l-r'r-m :$■;!■ :'■■;';''. ■^"i' aV -. ^ * , -/^^ ■% -.0* \ \>.,^^ .^^% \' . --v ^/ ^ /< ^<^■ 4^\* .>^^ « I \ " \^ ^f a\ , N c -7;^ >0 Q. -0' ^ ■^^ ^\ >^^ '^- '^\ ,0 o ^^ -* sC^- v-^' N^^y: .-0^ '<*' ' "k ^ ' .^" ^0^ ^\-'> *0o xO° v$74 'Z-'Z-^ LIPPINCOTT'S EDUCATIONAL GUIDES EDITED BY W. F. RUSSELL, Ph.D. DEAN, COLLEGE OF EDUCATION, UNIVERSITY OF IOWA \ ''lippincott's educational guides EDITED BY W. F. RUSSELL, Ph.D. DKAN, COI.MiOK OK EDUCATION, UNIVERSITY OF IOWA 'brightness and dullness in children BY HiaiBERT ^yOODROW, Ph.D. ASSOCIATE I'UOKESSOK OK l'SYCHOLO<.Y IN TME UNIVEKSIIY OI- MINNESOTA / ILLUSTRATED IMHT.ADKLPTTIA " CTTICAGO :: LONDON :: MONTREAL J. B. LIPPINCOTT COMPANY LB//3I COPYRIGHT, 19 1 9, BY J. B. LIPPINCOTT COMPANY w*' DEC 31 <91d PRINTED BY J. B. LIPPINCOTT COMPANY AT THE WASHINGTON SQUARE PRESS PHILADELPHIA, U. S. A. i ©C!,A56i288 sy" CONTENTS CHAPTER PAGE I Introduction 9 II The Measurement of Intelligence 19 Pioneer studies in the measurement of intelligence. The Binet-Simon measuring scale. Evidence of the accuracy of the revisions of the Binet-Simon scale. Criticism of the Binet-Simon scale. Group tests. III Brightness and Dullness 41 Distinction between mental age and brightness. The lowest degrees of brightness : Definitions in terms of social status and definitions in terms of mental age. Years of retardation as a basis for definition of degrees of brightness. Intelligence quotients. Application of intelligence quotients to the definition of all degrees of brightness. Race, class and sex differences in in elligence. IV Brains 61 The relation of mind to body The relation of brain development to the evolution of animal intelligence. The development of the brain in children. The relation of the brain to differences in intelligence in adults. V Physical Defects 81 The relation of physical defects to intelligence. Defec- tive vision. Defective hearing Non-sensory defects. Stigmata of degeneracy. Medical inspection and its relation to the teacher. VI Anatomical Age : 97 The various child ages. Anatomical age. Indices of anatomical age. The eruption of teeth. The ossifica- tion of the wrist boft,eg;'fVaVaatiGn in the anatomical age of children. Sex dififerences. Anatomical age and mental ability. Relation of height and weight to anatomical age and to mental ability. The educa- tional value of measurements of anatomical age. VII Pedagogical Age .^ ,% ^^^ Definition cA pedagogical age on the basis of "normal" ages. The prevalence of pedagogical retardation and advancement. Elimination as studied by^ age and grade distributions. The relation of elimination to pedagogical retardation. Causes of pedagogical retarda- tion. Remedial measures. 6 CONTENTS VIII Simple Mental Processes 147 Intelligent behavior and mind. Methods of measuring sensory capacity and estimating its relation to intelli- gence. The relation of sensory capacity to intelligence. Comparison of the senses of primitive and advanced races. Perception. Imagery. Feelings. IX Association, Memory and Attention 171 Free association. Controlled association. Memory. Attention. X Complex Mental Processes 190 Reasoning. Instincts and emotions. Will: (i) Per- sistence; (2) Suggestibility and impulse. XI Mental Organization 213 The problem of the interrelationsliip of mental traits. Three psychological theories of mental organization. Corresponding theories of brain action. The evidence from correlations. Spearman's two-factor theory. A multifactor theory. XII Heredity 232 Definition of heredity and environment. Methods of investigation. Results of the correlational method. Pedigrees of the feeble-minded. The Kallikak family. The inheritance of superior intelligence. The Edwards family. Conclusion. XIII The Organization of Education 254 The relation of education to heredity and growth. The necessity for special education for bright and dull children. Provision for dull and superior children. The problem of the feeble-minded. XIV Educational Methods 275 The savage of the Aveyron. The physiological method. Critical estimate of the physiological method. Experi- ments in the education of children with exceptional abilities. The training of mental capacities. Index of Authors 311 Index of Subjects 3^5 ILLUSTRATIONS FIG. PAGE 1. Distribution of the Mental Ages of One Hundred Ten-year-old School Children 32 2. Growth in Mental Age 48 3. Diagrammatic Representation of the Cortical Layers and of the Different Types of Neurones' 64 4. The Growth of the Brain in Weight 68 5. Comparison of Sections of the Cortex of Normal and Feeble- minded Persons 76 6. The Permanent Teeth 102 7. Radiographs Showing the Variation in Anatomical Age of Ten-year-old Children i lO 8. Sex Differences in Anatomical Age of Ten-year-old Children 112 9. Tape Used in the Dotting Test 188 10. Ergograph Test 204 11. Children's Ergograph Curves 206 12. Showing Performance in Suggestion Test 209 13. Descendants of Martin Kallikak, Sr., by His Wife, and by a Feeble-minded Girl 246 BRIGHTNESS AND DULLNESS IN CHILDREN CHAPTER I INTRODUCTION The day before his fifth birthday, Francis Galton wrote the following letter ^ to his sister : My dear Adele : I am 4 years old and I can read any English book. I can say all the Latin Substantives and Adjectives and active verbs besides 52 lidts of Latin poetry. I can cast up any sum in addition and can multiply by 2, 3, 4, 5, 6, 7, 8, (9), 10, (11). I can also say the pence table. I read French a little and I know the clock. Francis Galton, Febuary 15, 1827. The only misspelling is in the word February. The numbers 9 and 11 are bracketed because one had been scratched out with a knife, and the other was covered by a bit of paper pasted over it. By the age of six, Galton was conversant with the Iliad and the Odyssey. At six and seven, he busied himself with collecting insects and minerals, which he is said to have classified and studied in more than a child- ish fashion. The following well-worded note proves that at the age of ten be was absorbed in religious questions : ^ From vol. i of Karl Pearson's " Life, Letters and Labors of Galton." Quoted by Terman in the American Journal of Psychology, vol. xviii, 1917, p. 210. 9 lo INTRODUCTION December 30, 1832. My dearest Papa: It is now my pleasure to disclose the most ardent wishes of my heart, which are to extract out of my boundless wealth in compound, money sufficient to make this addition to my unequaled library : The Hebrew Commonwealth by John 9 A Pastor Advice 2 Hornne's commentaries on the Psalms 4 Paley's Evidence on Christianity 2 Jones Biblical Cyclopedia 10 27 Notwithstanding his wonderful precociousness, this noted EngHsh scientist accompHshed his best work at an advanced age. Hereditary Genius was pubHshed in his fiftieth year; Natural Inheritance in his sixty-eighth. Galton is only one among a vast number of men of genius who are known to have displayed exceptional ability in childhood. The majority of poets and musicians show their genius at a very early age. Tasso was famous at the age of eight and Southey wrote dramas before that age; at the age of three, Mozart took piano lessons; at four, he played minuets and composed short pieces; and at five, he performed in public. In the field of science and philosophy, among those who were famous in their youth are Lord Bacon, Kant, Locke, Berkeley, Descartes, Spinoza, and Lord Macaulay. Macaulay read incessantly at the age of three. At seven, he began A Compendium of Universal History, and at eight he wrote A Treatise to Convert the Natives of Malabar to Christianity. All of these men lived to a fairly advanced age and continued their creative work through- out the greater part of their lives. I have referred particularly to Galton merely because INTRODUCTION ii he belongs to that group of geniuses of whom it is some- times alleged that they show no signs of exceptional ability until late in life. Clearly in Galton's case, the idea that genius develops slowly is based on ignorance : Galton was a genius even in his boyhood. Whether with more abundant information we should find all men of genius to have been exceptional children, it is impossible to say. On the other hand, of those placed at the opposite extreme of intelligence, the feeble-minded, it may be said with assurance that their careers as adults are faith- fully foreshadowed by the performances of their child- hood, even of their very early childhood. And since our interest at present is in differences in intelligence which exist in children, it is well worth our while to consider the contrast between the early record of Francis Galton and the following one of a girl named Abbie, a case typical of high-grade feeble-mindedness of the sort that is not uncommon in the special classes of our city schools. Admitted to the New Jersey Training School for Feeble-Minded Boys and Girls in 1900, at the age of eleven, Abbie was small for her age, left-handed, and awkward. She always put the same foot forward when going up or down stairs ; she knew her letters but could not read; she could count to ten; she knew some color and form ; and she sang a number of hymns that she had learned at home. Her sight and hearing were normal, and she was fond of play.^ Among Abbie' s more unfavorable characteristics were a bad memory and a poor povv-er of imitation. She was gluttonous, untidy, untruth- ful, sly and profane. Three months after her admission she could thread ' The Training School, vol. vii, 1910, p. 182. 12 INTRODUCTION a needle and sew on buttons, could dust and rub floors a little, had learned to read A man ran and / see a man (sometimes), counted to twenty, and, with help, could do such number work as this : J i _i. For ten years she went to school. *' For ten years," runs the report, '' her teachers struggled heroically to give her the mastery of something. Little less than mar- velous is the optimism and faithfulness of those teachers ! We see them struggling on month after month, not in that perfunctory way born of discouragement or con- scious failure, but with that courage and cheerfulness which comes from grasping at every straw of encourage- ment, of progress, of fancied improvement. Had these teachers become discouraged, we would have to admit that perhaps the result might be due to that fact. But there is no sign of giving up in all these years. Within the last few months, however, there has appeared the feeling that Abbie has reached her limit. She will be twenty-two years old before long. " To-day she is still small for her age. She can braid corn-husks a little; can make a bed; can iron an apron; cannot count the cost of three one-cent stamps and three two-cent stamps, with the stamps before her; cannot repeat five figures or a sentence of fifteen words; defines only in terms of use; can read a few sentences, spell a few words and write about twenty-five words from memory ; knows the days of the week, but not the months of the year; and does not know how many fingers she has on both hands." Francis Galton and little Abbie represent opposite poles of human intelligence; they typify the extremes and between them are any number of variations. The differences existing between individuals in regard to INTRODUCTION 13 common sense, mental ability and character are enormous. Obviously, they are of the utmost importance in deter- mining the constitution of society and the aims of educa- tion. These differences come most clearly to view in the successes and failures of adult life. What is opportunity for one man is discouragement for another ; as one climbs to eminence, another, starting v^ith equal opportunities, treads a path that leads him to the poor-house. The struggle of life constitutes the test, a test which some pass gloriously and others utterly fail. Adult life, how- ever, merely emphasizes the existence of individual dif- ferences in endowment ; it does not create them. For the most part these differences, determining factors in the careers of men and women, are present in early childhood. In almost any American school the children 'display nearly every degree of intelligence between the brilliant Francis Galton and the feeble-minded Abbie. Psychological and pedagogical investigations con- ducted during the last decade have clearly demonstrated the fact that children of the same age and the same amount of schooling vary from one to five years or more in mental capacity as well as in their school grade, and that the number of children who differ widely from what may be termed the normal is very much greater than has been generally supposed. Of course the factors which determine the rank a child takes, whether in school or out of school, are innumerable. One child may enjoy better health than another, be better nourished and less easily fatigued, or have fewer physical defects. One may study harder or with more interest and concentration of attention than another. Home environment is of great importance. A child reared in a slum, by ignorant or wicked parents incapable of training him properly, cannot 14 INTRODUCTION fairly compete with one who is influenced from the first by culture and sane discipline. Again, the quality of a child's companions is a crucial element. Differences in intelli- gence may depend upon ability or disability in some particular mental function, such as the capacity for visualization or for rote memory. Countless circum- stances and conditions affect a child's success in the innu- merable performances which make up his life; but the most comprehensive and fundamental of them all, to which the tests must inevitably return, is, finally, his innate brightness or dullness. Now brightness and dullness refer merely to a child's comparative intelligence. A bright child is one with more than ordinary intelligence and a dull child one with less than ordinary intelligence. Evidently, then, if we wish to act wisely in guiding the development of our children, we must understand the nature of intelligence, the factors affecting it, and the consideration that must be given it in the choice of educational aims and methods. These sub- jects are discussed in the following pages. Our knowledge of them has greatly advanced since 1908, when Binet and Simon perfected their famous method of measuring intelligence. This information is practically new, and is constantly and rapidly increasing, but it already constitutes one of the most important chapters of modern science. Although, as I have said, a child's success in school is not determined solely by his intelligence, but depends on a great many other factors, every one of these stands in some relationship to intelligence. Consequently they must be included in any thorough study of brightness and dullness. One cannot understand the nature of intelli- gence without studying its relation to health, to the development of the brain and the rest of the body, its INTRODUCTION 15 relation to the senses and to the various mental processes such as attention, memory and judgment and to defects in these, the degree to which it is modifiable by learning and by the environment and, on the other hand, the degree to which it is fixed by heredity. It is evident that the subject of intelligence is a broad one, as broad as the whole field of psychology, and that it touches upon other sciences as well. It deals with fundamental problems to be met with in all branches of human activity. Heretofore the lower degrees of intelligence, dullness and feeble-mindedness, have forced themselves most strongly upon the attention of investigators. Because more is known about the lower end of the scale than the higher, I have purposely emphasized, in this discussion, the higher. To be* sure, the problem of feeble-mindedness is enormously important. "Feeble-mindedness," wroteAmos Butler, " produces more pauperism, degeneracy and crime than any other one force. It touches every form of chari- table activity. It is felt in every part of our land. It affects in some way all our people." ^ But facts concern- ing feeble-mindedness constitute only a small part of our knowledge about intelligence. We are beginning nowa- days to study the exceptionally bright child as well as the dull one, realizing that, if it is worth while to dis- cover the best training for a feeble-minded girl like Abbie, it is many times worth while to seek out adequate prepara- tion for the future leaders in literature and art, science, business, and government. But in dealing with bright children or with dull, there are certain laws and relation- ships which are fundamental, and which hold for all *"The Burden of Feeble-Mindedness." Proceedings of the 34ih Conference of Charities and Corrections, 1907, p. 10. i6 INTRODUCTION degrees of intelligence. There has grown up a science of general intelligence. This book is intended to serve as an introduction to that science. By the science of intelligence I do not mean simply the art of applying a modern scale for the measurement of intelligence. To apply these scales is the task of the specially trained expert. The scales themselves are still in the experimental stage, and so are constantly being modified. Therefore, it requires a prohibitive amount of time and study to keep abreast with the latest develop- ments, to say nothing of the time necessary to give the tests so that no one but a specialist has the opportunity and skill to be a good intelligence tester. However, no matter how successfully the tests of intelligence are con- ducted, the immediate results in themselves have little • value. They by no means constitute an adequate mental diagnosis. They must be interpreted in connection with other data before any definite conclusions can be drawn. The intelligence tester needs, in addition to his technical skill, a knowledge of intelligence in all its aspects and relations — a veiy broad and tliorough knowledge. And to the average worker with children, to the educator, whether administrator or teacher, just this broader knowledge is of infinite value. It is with this material that the following pages are concerned ; they do not comprise a manual of intelligence testing. Some account, it is true, is given of the methods for measuring intelligence. This is done, however, for tlie light that a knowledge of these methods throws upon the meaning of intelligence, and upon the many important conclusions to which their use has led. The topic of intelligence is naturally of the utmost INTRODUCTION 17 concern to the educator, because education deals primarily with the development or training of intelligence. The teacher must grapple with problems of the development of intelligence, and of individual differences in intelli- gence, not occasionally and incidentally, but constantly. These are the very gist of her work. Without a thorough understanding of the modern investigations along this line, and their significance, it is impossible for the teacher to know what she should aim to do or what methods she should employ in the accomplishment of her aims. The teacher of to-day needs a knowledge of the modern psychology of intelligence. She must know when it is desirable to try to bring a backward pupil up to grade, and when it is not, and why it usually is not. She should realize that the exceptionally bright child who seldom troubles her may be her greatest problem. She should understand the sources of the errors teachers often make in their estimates of brightness and dullness, such, for instance, as the failure to take properly into account differences in age. She should be familiar with the con- cept of mental age and with the method of classifying children as superior, dull, or normal by its aid more accurately than in any other manner, f The teacher should know that intelligence has a physical basis, and should understand the relation of intelligence to the brain and to physical defects.] This relation places heavy respon- sibilities upon her. Further, she ought to understand the part played by the various mental processes in the make-up of intelligence, and the interrelationship and organization of these processes. She should comprehend the relation- ship between mental ability and success and failure in school work, in order to determine upon the proper treat- i8 INTRODUCTION ment of over-age pupils, and in order to value the great problem of preventing children from dropping out of school before they have received the education that is their right. She must know that innate brightness and dullness can be recognized at an early age, and that they demand recognition as fundamental factors in the deter- mination both of the general school organization and of educational methods. Clearly, the science of education depends upon, and finds its surest foundation in, the science of intelligence. CHAPTER II THE MEASUREMENT OF INTELLIGENCE The successful measurement of intelligence, first accomplished by the method of Binet and Simon, is per- haps the most brilliant achievement of modern psychol- ogy. It supplied an imperative need long felt by all discerning persons engaged in work with children. The science of psychology has been vitalized and rejuvenated by this achievement, which, in its far-reaching and ever- growing developments in the fields of psychology and education, has exceeded the most sanguine expecta- tions of those men of clear vision labored towards its culmination. Pioneer Studies in the Measurement of Intelligence. — Work earlier than that of Binet, and, indeed, much of the earlier work of Binet himself, was directed not so much towards the measurement of intelligence as a whole as towards the development of tests for measuring various elementary features of human capacity. The great pio- neer in this sort of work was Francis Gal ton, who, in 1883, pubHshed an elaborate account of individual and racial differences.^ The object of his tests and measure- ments, he described as follows : " It is to obtain a general knowledge of the capacities of a man by sinking shafts, as it were, at a few critical points. In order to ascertain the best points for the purpose, the set of measures should be compared with an independent estimate of the man's ^ " Inquiries into Human Faculty." 19 20 THE MEASUREMENT OF INTELLIGENCE powers. We may thus leani which of the measurements are the most instructive." ^ Galton gathered much of his data by rather crude methods, such as mere casual observation. In some cases, however, he followed quasi-scientific procedures. He studied differences in mental imagery by elaborate ques- tionnaires ; the ability to make discriminations in weight, he tested by careful experiment; and for determining sensitivity to high pitches, and the limit at which pitches become too high to be audible, he devised a kind of whistle. One of these, he tells us, he had set into the end of his walking-stick, with a bit of rubber tubing concealed under the handle. A sudden squeeze of the tubing forced a little air into the whistle and caused it to sound. On his walks through zoological gardens, he amused himself by sounding this apparatus as near to the ears of the ani- mals, as he safely could. If the animals pricked up their ears, he concluded that they had heard the whistle; if they did not, that the tone was inaudible. Galton was followed by a large number of investiga- tors, who, while perfecting the precision of mental tests and increasing their number, made observations regard- ing their applicability to various practical problems. In Germany, Kraepelin inaugurated studies of the differ- ences between the mentally normal and the insane. In America, Cattell devised a set of tests which for a number of years were given to freshmen entering Columbia Uni- versity. These tests were designed to measure such capaci- ties as the following: Strength of grip, or the greatest possible squeeze of the hand; sensory discrimination by the skin, indicated by the distance that must separate two * Remarks, following an article by Cattell, on " Mental Tests and Measurements," in Mind, vol. xv, 1890, p. 380. PIONEER STUDIES 21 compass points in order that they may be felt as two; the sense of pain, measured by the amount of pressure on the ball of the hand required to produce a painful sen- sation ; the ability to discriminate weight marked by the least difference noticeable ; reaction time, the time elapsing before a stimulus, e.g., a loud sound, calls forth a move- ment made in response to it by the finger; visual space perception, determined by the ability to bisect a 50 cm. line; time estimation, shown in the ability to reproduce an interval of 10 seconds by taps made on the table; and memory, manifested by the number of letters that can be repeated correctly after one hearing.^ As measures of ability, Cattell's tests were chiefly negative in value.^ Other tests, however, which were directed primarily to the study of children, were some- what more successful. Gilbert, for example, established by a number of tests, norms of performance for school- children of all ages from 6 to 17. Besides finding an increase in ability with advance in years, he found some of his tests to correlate with the brightness of the children as estimated by their teachers. " The curves for reac- tion time gave the most positive results, showing that the brighter the child the more quickly he is able to act." ^ These tentative beginnings continued until finally it ap- peared possible to estabHsh norms whereby a child could be readily classified for pedagogical purposes.^ The work of American investigators was criticized by ^ " Mental Tests and Measurements." Mhid, vol. xv, pp. Z7A-Z77- * See Wissler, " Correlation of Mental and Physical Tests." Psychological Review Monograph Supplements, vol. iii, 1901, No. 16. ' ^ " Researches on the Mental and Physical Development of School Children." Studies from the Yale Psychological Laboratory, vol. ii, 1894, P- 94- ® See Kelley, " Psycho-Physical Tests of Normal and Abnormal Children." Psychological Review, vol. x, 1903, p. 371. 2 2 THE MEASUREMENT OF INTELLIGENCE Binet and Henri/ the distinguishecl French psychologists, on the ground that the tests employed measured mental processes which were too simple — which did not suffi- ciently involve the '* superior mental faculties." They accordingly prcKceded to devise a large number of tests, which, although simple in application, involved more com- plex mental activity. Instead of measuring the ability to distinguish slightly (Hft'erent weights or colors, they sought io obtain an appreciation of such i>owers as tluxsc of judgment, synthesis, imagination and aesthetic appreciation; often the mental finictions tested could not l>e exactly analyzed; it could only be said that they were complex. The Binet-Simon Measuring Scale. — The Binet-Simon scale represents a crystallization of the experience acquired through many years of exi)erimentation. For years before the perfection of this scale, Binet had studied the value of mental and physical tests. He had covered an extensive lield, including measurements of the head, height and weight, and tests of ixn-ceptiiMi. uienuM-y and attention. He had for years been experiuienting among the children in the schools of Paris, until he had acquired an expert knowledge of child psychology. The practical necessity of devising some means lor the measurement of intelligence was brought home to him with great force when, in iqo^, the French IMinister of Public Instruction made him a member of a com- mission appointed for the purpose of organizing classes for subnormal children in the public schools of Paris. How were subnormal children to be positively distin- guished? Very hazy notions surrounded the matter, and ' " La psychologic individuelle." L'AmUc psychologique, vol. ii, 1805. p. 4-*^». THE BINET-SIMON MEASURING SCALE 23 it was important that the selection of children for special classes shonld not l>e left to the nncertainties of personal opinion. It was under the incentive of this pressing and practical difficulty that Binel, in collaboration with Dr. Simon, produced the hrilliant synthesis known as the Jjinet-Simon measuring;- scale of intelligence. This scale, in its earliest j;uise, was published in 1905 and in its ])erfecte(l form in 1908. The Ih'net-Simon scale comprises a large number of intelligence tests arranged in a series of increasing diffi- culty. The tests re(iuire the answering of brief, direct (juestions and the performance of simple tasks, all bearing upon matters of every-day life. They manifest great variety and demand many different mental i)rocesses, as the following list shows. Subjects are asked to execute simple orders; to name familiar objects; to repeat short series of digits and short sentences; to compare lengths, and weights; to count, naming pieces of money, and mak- ing change; to define familiar, concrete terms and abstract terms; to point out similarities in the meaning of two words; to point out differences; to tell what they see in a complex picture; to copy geometrical figures or reproduce them from memory; to tell what ought tO' be done in various situations; to put together the words of a dissected sentence so that they make sense; and to recognize absurdities. Some authorities are of the opinion that the success oi the Binet and Simon tests is due to their preoccupation with the higher and more complex mental functions. Although there is some truth in this contention, many of Binet's tests are exceedingly simple; as simple as any of the older tests. Taken individually, Binet's tests have not been proved superior to, nor greatly different from the 24 THE MEASUREMENT OF INTELLIGENCE older tests. Indeed, some of the Binet tests, such as those calHng for weight discrimination and memory feats, are survivals of the oldest psychological tests in existence. The real secret of Binet's success lies in the fact that, after long years of experimenting with separate tests, he finally decided to use a large number of tests in combination. Intelligence, he decided, is too complex to be measured by any one test ; but by using in combination five or six quite dissimilar tests, he found immediately that he could obtain significant results. While the success of the Binet and Simon tests is due fundamentally to the use of a number of tests in com- bination, the world-wide popularity they so rapidly attained must be attributed largely to their arrangement by ages. They are all classified according to the age at which the average, or normal, child can pass them. Thus, tliere are five tests for four-year-old children, five others for children of five years, five, still different, for children of six years, and so on. The idea is simply that at each age the ordinary, normal child can do certain things which he could not do at an earlier age; and that by arranging a system of tests to test ability to do these things, one can determine to what age of a normal child the ability of any tested child corresponds. The age of the normal child whose ability is equalled by the tested child is said to be the mental age of the latter. It is thus an easy matter to understand just what the Binet tests do : they measure intelligence in terms of mental age. The desirability of obtaining an estimate of intelli- gence in terms of mental age had long been recognized.^ ^ See Rogers. " The Classification of the Feeble-Minded Based on !NIental Age." Reprinted from the Bulletin of the American Academy of Medicine, vol. xiii, 1912, No. 3. THE BINET-SIMON MEASURING SCALE 25 As far back as 1828, Esquirol, the first writer clearly to define the term idiocy, called attention to the fact that an idiot was incapable of acquiring the knowledge of other persons of his own age placed in similar conditions with himself.^ Duncan and Millard, in 1866, plainly ^thought in terms of mental age, when they wrote, concerning the various classes of feeble-minded, '' It is a very striking method of showing the mental deficiency of a member of any one of these classes to compare its mental gifts with those of children of perfect mind at younger ages." ^^ In the same vein, we find Down, in 1887, discussing as follows the classification of backward and feeble- minded children : '' In any given case we have to ask ourselves, can we in imagination put back the age two or more years and arrive thus at a time perfectly con- sistent with the mental condition of our patient? If he be a backward child, we shall have no difficulty in saying what period of life would be in harmony with his state. If, however, he be an idiot, there is no amount of imag- inary antedated age to which the present condition of the child corresponds." ^^ The concept of mental age is clearly implied, though not definitely formulated, in these passages. Mental age means a certain degree or amount of intelligence. A year's growth in mental age is a unit, although one which changes with age, for the measurement of intelligence. Each mental age stands for the degree of intelligence possessed by the normal child of the corresponding ® " Observations pour servir a rhistoire de I'idiotie." Les maladies mentales, Paris, 1828. 10 " A Manual for the Classification, Training, and Education of the Feeble-Minded, Imbecile, and Idiotic," p. 13. ""Mental Affections of Childhood and Youth," 1887. 26 THE MEASUREMENT OF INTELLIGENCE chronological age. To say that a child has a given mental age means simply that he behaves in the manner of the average, or normal, child of that age — that he is capable of doing the same things. Thus, if a child ten years of age can do only the same things that a normal eight-year- old child can do, if he passes only the same tests, then, in spite of the fact that his chronological age is ten, his mental age is only eight ; he is two years mentally retarded. On the other hand, if a child of ten is found to be capable of the same mental performances as the average twelve- year-old child, we say that his mental age is twelve and that he is two years mentally advanced. Binet and Simon adopted this concept of mental age, and arranged their tests in such a manner as to measure it. In order to determine what normal children of each chronological age could do, they tried out their assort- ment of tests on children of all ages and thus settled upon those which could be passed by a majority of children of each age. In this way, they secured certain tests which six-year-old children could pass, but which most five-year-olds could not; others which most seven- year-olds could pass, but most six-year-olds could not, and so on. It is such a series of tests, classified in sets according to the age at which normal children ought to pass them, that constitutes the Binet-Simon scale for the measurement of intelligence. It extends from the age of three to the age of fifteen. To illustrate the arrangement of these test-perform- ances by years, I may cite the original list of accomplish- ments, in an abbreviated form, for children of the ages three to twelve.^ ^ "Goddard, " The Binet-Simon Measuring Scale for Intelligence." The Training School, vol. vi, 1910, pp. 146-154. THE BINET-SIMON MEASURING SCALE 27 Mental Age Four Years 1. Gives sex of self. 2. Names familiar objects (key, knife and penny). 3. Repeats correctly three digits, e.g., " 7-2-9." 4. Tells which of two lines is the longer (5 cms. and 6 cms.). Mental Age Five Years 1. Correctly compares 3 and 12 grams and 6 and 15 grams. 2. Copies a square of 3 or 4 centimeters well enough to recognize it as a square. 3. Repeats 10 syllables, e.g., " His name is John. He is a very good boy." 4. Counts four pennies placed in a row. 5. Re-forms a visiting card from the two pieces made by cutting one diagonally. Mental Age Six Years 1. Tells whether it is morning or afternoon. 2. Defines by use at least three of the following: fork, table, chair, horse, mama. "At four years, half the children define by 'use': it in- creases a little at five, and at six practically all define this way. Not before nine do the majority give the definitions that are * better than by use.' " 3. Executes three simple commissions given at once. 4. Indicates right hand and left ear. 5. Chooses the prettier of two heads, one pretty, the other very ugly, when they are shown in pairs. Mental Age Seven Years 1. Counts thirteen pennies placed in a row. 2. Tells what he sees in pictures. Describes instead of simply naming things. 3. Tells what is lacking when shown pictures of a head lacking an eye, a mouth or a nose, or of a head and body lacking arms. 4. Copies a diamond. 5. Names promptly four colors— red, blue, green and yellow. Mental Age Eight Years 1. Tells difference between a butterfly and a fly; between wood and glass; between paper and pasteboard. 2. Counts backwards from 20 to i, in 20 seconds. 3. Names days of the week in 10 seconds. 4. Tells how much they are worth, when shown three one-cent and three two-cent stamps. 5. Repeats correctly five digits, e.g., *' 4-7-3-9-5 " 28 THE MEASUREMENT OF INTELLIGENCE "Mental Age Nine Years 1. Makes change — 9 cents out of 25. 2. Gives definitions better than by use. 3. Names the day of the week, the month, the day of the month, and the year. 4. Recites the months of the year in 15 seconds. 5. Arranges in correct order a series of weights of 6, 9, 12, 15 and 18 grams. Mental Age Ten Years 1. Names nine different pieces of money. 2. Draws two simple geometrical designs from memory, 3. Repeats six digits. 4. Answers intelligently simple problem questions, e.g., " What ought one to do before undertaking something important?" 5. Uses three words, as New York, money and river, in one sentence. Mental Age Eleven Years 1. Detects the nonsense in absurd statements." 2. Uses three words in one sentence (given also at age ten). 3. Gives sixty words in three minutes. 4. Finds three words in one minute which rhyme with words like day, mill or spring. 5. Forms a sentence in one minute out of ten printed words in dis- connected order, as the following: started — the — for — an— early— hour — we — country — at — . Mental Age Twelve Years 1. Repeats correctly seven digits, once in three trials. 2. Defines charity, justice, goodness. 3. Repeats a sentence of twenty-six syllables. 4. Resists suggestion. 5. Solves problems of facts, (a) "A person who was walking in the forest of Fontainebleau suddenly stopped much frightened and hastened to the nearest poHce and reported that he had seen hanging from the limb of a tree a — what? " (Zj) " My neighbor has been having strange visitors. He has received one after the other a physician, a lawyer and a clergyman. What has happened at the house of my neighbor ? " It must be clearly understood that not all children of a given mental age will pass all the tests for that age. Owing to the unequal degree of development of the differ- ent mental functions, it nearly always happens that a child "See Chapter X, p. 190. REVISIONS OF THE BINET-SIMON SCALE 29 who fails on one or two of the tests of one age can pass some of the tests for the next higher age. Consequently the rule for determining the mental age of a child is to take the highest mental age for which all tests are passed plus one-fifth of a year for each additional test. Evidence of the Accuracy of the Revisions of the Binet-Simon Scale. — The Binet tests were promptly intro- duced into America, chiefly through the translation and revision of Dr. Goddard, who used the tests extensively and gave them an enthusiastic endorsement. The pub- lished data clearly indicated, however, that the tests were capable of improvement. At the lower ages they showed far more children advanced than retarded, whereas at the upper ages they rated the majority of children as retarded. Plainly, they were too easy at the lower ages and too hard at the upper ages. No sooner were these imperfections recognized than psychologists in various parts of the country undertook their elimination. Elaborate experimental work was carried on, and the standards to which these tests had to conform in order to be entirely reliable, were taken under consideration. As the criteria of reliability were established, the tests were revised to conform to them.^* Some of the tests were shifted to different ages and others replaced by better ones. The amount of painstaking, scientific work done upon these tests was enormous. As a result, the Binet tests, in their latest form, have an " Kuhlmann, " A Revision of the Binet-Simon System for Meas- uring the Intelligence of Children," Journal of Psycho-Asthenics, Monograph Supplements, vol. i, No. i, 1912, and "The Measurement of Mental Development," Faribault, Minnesota, 1917; Yerkes, Bridges and Hardwick, " A Point Scale for Measuring Mental Ability," 1915 ; and Terman, "The Measurement of Intelligence," 1916, and "The Stanford Revision and Extension of the Binet-Simon Scale for Measuring Intelligence," 1917. 30 THE MEASUREMENT OF INTELLIGENCE unquestioned validity. An examination of the evidence makes this clear. There is scarcely an important criterion of accuracy with which the tests do not comply. The accuracy of the tests is to be judged in two ways : First, by the results witli groups of children, and, second, by results with individual children. Groups of children who are all of the same age offer the advantage that, when they are large, it is safe to assume that the older the group the greater the average intelligence. We can be sure that we have ranked the age groups according to intelligence when we have ranked them according to age. We thus obtain through the use of groups a natural scale of intelligence by which to test our methods before applying them to individual children. The first problem, then, was to shape the scale for measuring mental age so that it was reliable with groups. By definition, mental age should equal chronological age in the case of the average or median child. The median child is one who stands at the middle of a large group of children of his own age. Thus, after we have meas- ured the mental age of a large group, all of the same chronological age, and arranged the mental ages in a column from highest to lowest, if we count down from the top to the middle of the column, we should find at the middle a mental age exactly equal to the chronological age of the group. That is, the middle or median mental age of a group of children who are equally old in years should agree with the chronological age of the group. The agreement should be exact and must be established for all ages. After* many revisions, this agreement has been secured; sO' that now a user of the scale may be confident that with a large group of six-year-old children the median mental age obtained will be six, and that REVISIONS OF THE BINET-SIMON SCALE 31 with a large group of seven-year-old children, it will be seven, etc. It is very important to note the distribution of chil- dren's mental ages about the median. Most children have a mental age very close to the median. The others are usually one or two years above or below it, and taper off in numbers gradually and symmetrically. This characteristic distribution is illustrated fairly well by the following results obtained with one hundred Minneapolis school children, between ten and eleven years of age, chronologically. Mental Ages of One Hundred Ten-Year-Old Children Mental Age Number of Children From 7.5 through 8.0 i From 8.0 through 8.5 o From 8.5 through 9.0 3 From 9,0 through 9.5 11 From 9.5 through lo.o 19 From lo.o through 10.5 '. 30 From 10.5 through ii.o 17 From II.O through 11.5 9 From 1 1.5 through 12.0 6 From 12.0 through 12,5 i From 12.5 through 13.0 3 The average chronological age of the group is ten years and five months, and the average mental age very nearly the same, namely, ten years and four months. The boys and girls in the group average about the same in chronological age, but the girls are ahead of the boys in mental age. The average mental age of the fifty-three girls is ten years and six months ; that of the forty-seven boys is only ten years and one month. We may chart the distribution of these one hundred children along the scale of mental age, by constructing a figure in which the mental ages are represented along its base line and the number of children having each of 32 THE MEASUREMENT OF INTELLIGENCE the mental ages by its height. We thus obtain the accom- panying figure (Fig. i). The irregularity in Fig. i is due to the fact that it is based on a comparatively small number of children and that it does not take into account fractions of less than one-half year in mental age. With a very large group, and with measurements in terms of very small fractions ^. ^ :^ ::^ Fig. I.- -Distribution of the mental ages of one hundred ten-year-old school children. of a year, we should get a smooth curve, resembling what is known as a normal distribution curve. This curve would be smooth and symmetrical, fitting, as well as possible, the outlines of Figure No. i. It would show, even better than the figure, that the number of children above the median mental age is equal to the number below it ; and that as the distance above or below increases the number of children decreases. It is sometimes consid- ered a sign of accuracy when the mental ages of a large group of children to whom the tests are applied turn out REVISIONS OF THE BINET-SIMON SCALE 33 to be distributed symmetrically, in accordance with nor- mal distribution, around the median mental age. As a matter of fact, however, the distribution curves do not prove the accuracy of the tests. Rather they have value only insofar as we may assume that accuracy has been attained. We know that the tests are accurate in regard to the average result with large groups. This is proved, as I have indicated, by the equality between the median mental age and the chronological age of the group. To prove their accuracy in individual cases is much more difficult, for there is no way to make certain 'that a measurement of any particular child's intelligence is correct without knowing beforehand how intelligent the child is. And how are we to determine the intelligence of a child except by the use of our measuring scale? There is no certain method. We must go ahead and make our measurements, then watch to see whether or not the future success of the child harmonizes with them. Of great aid is the rating given the child by his teachers and the progress he makes in school. The most accurate rating of the intelligence of chil- dren that can be secured from school work is that obtained by classifying children of the same age according to their grade. In any school system, children of one certain age are scattered over four or five grades ; and it is reasonable to suppose that those who are in the lower grades are less intelligent than those of the same age in the upper grades. Certainly there are many objections to assuming a perfect correspondence between school grade and intelligence; but it is reasonable to expect a considerable correlation. Investisratlon shows that this correlation exists. The revised Binet tests show for children of each age a regular 3 34 THE MEASUREMENT OF INTELLIGENCE increase in mental age with the grade attained. For example, eleven-year-old children who are still in the second or third grade instead of the fourth or fifth, will usually be found to be several years below eleven in men- tal age, whereas eleven-year-old children who have reached the sixth or seventh grade will be found to aver- age a year or so above eleven in mental age. Similar results have been obtained for all the school ages.^^ Exceptions to the correspondence between mental age and school standing are very common indeed. A careful study of these exceptions, however, usually leads to the strongest possible proof of the accuracy of the intelli- gence tests. There are two cases very frequently met with: One, that of the child who has been promoted because of his age regardless of scholastic attainments, the other, more serious, that of the child who has lost interest in his work and has been retarded because his teacher failed to understand his personality or to appreciate his mental gifts. The promotion of childrem simply on account of their age is a phenomenon with w^iich all teachers are familiar; the holding back of really brilliant children is not so commonly recognized. By the study of these latter cases, however, more readily than in any other way, will one acquire respect for the Binet intelli- gence tests. As a striking illustration, consider the case of Louis R. Louis was nine years and ten months old. When tested, he was found to have a mental age of twelve years and nine months, nearly three years aliead of his chrono- logical age. So high a mental age is very unusual for " See Kuhlmann, " Some Results of Examining a Thousand Public School Children, with a Revision of the Binet-Simon Tests of Intelligence by Untrained Examiners." Toiirnal of Psycho- Asthenics, vol. xviii, 1914, Pp. 242-245. REVISIONS OF THE BINET-SIMON SCALE 35 a nine-year-old child. It indicated that he had sufficient mental ability to do work of the fifth or sixth grade. Actually, he was in the *' B " class of the fourth grade. Now which was the true indicator of his intelligence, his school grade or the mental age given by the intelligence tests? His record will show. The following extract was taken from the teacher's report to the superintendent in January : Louis R. was not promoted to the "A" class of the fourth grade, because his work in the " B " class does not show continu- ous improvement, but is erratic. If he would apply himself he could do the work fairly well, but he will do one or two problems in arithmetic and let the rest go. He spends most of his time trying to make aeroplanes, etc., out of paper, or by whittling them from little blocks of wood which he brings to school. He loses interest in all school work after a few minutes. He learned to do long division with only one explanation — did two problems correctly — then quit trying and failed systematically after that. The cause of the boy's failure is obvious. His teacher could not establish a point of contact between his active mind and his school work. He is a healthy, energetic German boy whose father is well known all over the state as a wealthy and successful cattleman. His parents want the boy to have every advantage possible. Louis was tested in January, 19 18, and recommended for special promotion. He was also transferred to another building where the fifth grade teacher was an expert with children. Inquiry was made in May, 191 8, regarding the boy's progress, and the fifth-grade teacher said he had again been promoted on trial to *' B " sixth grade — except in arithmetic ; she was giving him special help in arithmetic out of school hours, so that by fall he could enter the "A" sixth class without condition. Cases like that of Louis R. are not uncommon. Many 36 THE MEASUREMENT OF INTELLIGENCE such children, considered dullards in school, have devel- oped into men of undoubted genius. ^^ Oliver Goldsmith was regarded as a stupid blockhead by his earlier teacher ; it was only when he went to a second school that he found a teacher who realized his powerful intellect. Byron was the butt of his class because he did not learn his lessons. Yet at Harrbw, he found a teacher who recognized his talents. " I soon found," said this teacher, *' that a wild mountain colt had been committed to my care. But there was mind in his eye." Clearly there is a great field of use- fulness for the Binet tests in the discovery of superior mental abilities which might otherwise pass unnoticed. Considering all the evidence, one must concede to the Binet tests a high degree of reliability. Their accuracy with groups can be demonstrated with mathematical pre- cision, and their accuracy in the individual case becomes more convincing with use. They certainly offer the best means at hand for the appreciation of child intelligence. With their aid a more accurate rating can be secured in forty minutes than through the teacher's estimates based on a year of observation. At the same time, they are not perfect ; and now that we have considered the proofs of their accuracy, it will be wxU to give attention to some of their limitations. Criticism of the Binet-Simon Scale. — One of the most serious charges made against the Binet tests is that the ability to pass them depends too much upon the accidents of schooling and of environment, that it is not wholly decided by ingrained capacity which alone is properly called intelligence, but upon the favorableness of the child's early training. It is said that a child who has not been to school at all could not pass some of the tests "Swift, "Mind in the Making," 1908, pp. 95-115. CRITICISM OF THE BINET-SIMON SCALE 37 which a child who had been in school could manage with- out difficulty. That the tests are not altogether free from this error may be admitted, but the charge is not so serious as it might seem, for the Binet tests are not concerned with those things which a child has to be taught, but only with those things which a child naturally learns as he grows older. After all, whether or not a child acquires knowledge depends largely upon his innate intelligence. Any ordi- nary environment offers abundant opportunities for the acquisition of all the knowledge required by the revised Binet tests. Whether this little knowledge is acquired or not may then be simply a question of the child^s capacity to take advantage of his opportunities ; and it is precisely this capacity to take advantage of opportunities which, is meant by intelligence and which it is the aim of the tests to measure. It may in general be said that a child's mental age is determined by growth of capacities rather than by what he learns. I have found that feeble-minded children of nine years mental age improve with practice in simple mental operations just as rapidly as do normal children of the same mental age.^^ Yet in spite of this ability to learn, the feeble-minded children did not increase in men- tal age. Practically they remained at the mental age of nine years. They averaged fourteen years chronologically and probably had reached their maximum mental age. Evidently, then, the ability to change from a low mental age to a higher is not a matter of learning power. It is a capacity for mental growth. What a child can learn and " Woodrow, " Practice and Transference in Normal and Feeble- Minded Children." Journal of Educational Psychology, vol. viii, 1917, pp. 85-96 and 151-165. 38 THE MEASUREMENT OF INTELLIGENCE how fast he can learn, depends upon his mental age; but learning does not greatly affect the rate of growth in mental age. This is true of adults. They continue to learn throughout their lives; but they do not continue to increase in mental age after they have reached the adult stage. Another consideration, sometimes urged as a short- coming of the Binet tests is that they fail to detect all mental abnonnalities. They do not serve for the diag- nosis of such disorders as epilepsy or hysteria, nor for the measurement of criminal tendencies. They do not always bring to light such defects of character as lazi- ness, ungovernable temper, uncontrollable sex impulses, and openness to suggestion. These are not valid objec- tions, however. The aim of the Binet tests is solely to measure intelligence. The analysis of character is a differ- ent matter. Nevertheless, the Binet tests have been of great value in making clearer the relationship between intelligence and character. By their use it has been estab- lished that a considerable percentage of persons con- victed of crime and immorality are of very low mentality. They arc widely used in juvenile courts, where they are of great value in enabling the judge to form an idea of the probable future of the cliild. They have even saved the lives of youthful murderers by proving that the mur- derers were imbeciles who could not possibly understand the nature and seriousness of their act.^® One other limitation of the Binet tests which should be kept in mind is that they do not entail a rigid mechani- cal procedure which does away with the personality of the one who uses it. It is of course true that not the slightest " Goddard. " A Brief Report on Two Cases of Criminal Imbe- cility." Journal of Psycho-Asthcnics, vol. xix, 1914, pp. 32-35. CRITICISM OF THE BINET-SIMON SCALE 39 detail of the tests may be changed; the directions for giving tliem must be strictly followed. Even so, the influence of the tester's personality cannot be entirely eliminated. And when the measurement is completed, the result should never be regarded as an end accomplished, but merely as one means toward a better estimate of the child's mentality. The Binet tests must always be sup- plemented by further observations, and interpreted in the light of all the knowledge that can be obtained concerning the child's health and physical condition, his school record, his parents and his home life. The Binet tests do not suspend the need for expert insight into child nature nor the need for common sense on the part of the person who is to realize their full value. All in all, the Binet measuring scale is a wonderful achievement. Psychology has made no other single con- tribution that is of such great practical value to the science and the art of education. The Binet scale has not only afforded the means of proving the absolute necessity for greater adaptation of education to the possibilities of the individual pupil, but it stands as the most serviceable in- strument for the determination of those possibilities. It is the confident prediction of many educators that intelli- gence tests will soon become part of the necessary routine of the schoolroom; and in all probability the day is not far off. Already they are in extensive use throughout the schools of many nations. During the war, it was de- cided to give intelligence tests to all soldiers in the United States Army. These army tests, being intended for adults rather than children, differ from the Binet tests in all respects except their aim^ — the measurement of intelligence. Intelligence tests are now given by the University of Minnesota to all its freshmen, in the pro- 40 THE MEASUREMENT OF INTELLIGENCE fessional schools as Avell as in the academic college, and have been found of real value. Group Tests. — Anticipating the extension of mental testing to all school children, psychologists have for some time been at Avork on the perfection of group tests for children. Group tests cannot take the place of the indi- vidual examination. The idea is that they can be made sufficiently accurate for rapid surveys to determine those who should be tested individually. One such system of group tests ^^ is largely an ingenious adaptation of various revisions of the Binet tests to group work. It is now being used in a survey of the schools of an entire county in Minnesota, to locate all cases of doubtful mentality. Another system, intended only for children who can read and write, is constructed along lines quite different from the Binet scale.-^^ Instead of giving different tests at each age, it gives the same tests at all ages. These tests, how- ever, are not tests which a child either passes or fails, but tests in which he obtains .a certain score, which may be either high or low, as in a spelling test or an arithmetic test. The intelligence of the child is evaluated by com- paring tlie scores he malvcs in the various tests Avith norms that have been established by giving the tests to a large number of children of each age. " Frances Lowell, " A Preliminary Report of Some Group Tests of General Intelligence," Journal of Educational Psychology, vol. x, 1 91 9, No. 6. ''Arthur and Woodrow, "An Absolute Intelligence Scale," Journal of Applied Psychology, vol. iii, I9i9> No. 2. CHAPTER III BRIGHTNESS AND DULLNESS Distinction Between Mental Age and Brightness. — The word intelligence has two quite distinct meanings, which-need to be carefully distinguished. In one sense, intelligence is something which increases in amount with age. It is that which is measured bj. mental age. In this sense of the term, a child of ten years of age has much more intelligence than a child of three years of age, even if the ten-year-old child is dull and the three-year-old is bright. In the other sense of the term, intelligence is something that remains more or less constant throughout life. This is the sense in which one employs the term when he speaks of a child as highly intelligent without specifying his age. What one really means, in this case, is that the child has more^intelligence than other children of his own age. In the first sense of the term, intelligence is an absolute amount, like height described in inches; in the second, a relation, like height described as tallness or shortness. Throughout the present discussion the term intelli- gence, if unqualified, is used only in the first sense, in the sense of mental age. This makes it necessary to decide upon a different name for intelligence in the second sense. The proposal has been made to use the term brightness, meaning by brightness any degree thereof from extreme idiocy to genius of the highest order. I have adopted this proposal, and shall use the word brightness in this broad sense. It is less awkward than the term relative intelli- 41 42 BRIGHTNESS AND DULLNESS gence. Children who are ordinarily called bright, that is, children who are the opposite of dull, we shall term superior. Thus, according to this terminology, both dull- ness and superiority are degrees of brightness, dullness being a low degree of brightness and superiority a high degree of brightness. I The mental age of a child does not tell us how bright \he is. Two children may have the same mental ages and yet differ enormously in brightness. Obviously, the mean- ing of a given mental age depends upon the clironological age that goes with it. If a child's mental age is much less than his chronological age, he is dull; if it is greater, he is superior. But if we ask how much less or how much greater, we immediately raise the w-hole problem of the classification of children. The problem is an important one. Sensible planning of a child's education must pre- suppose an estimate of the degree of his brightness. In borderline cases, the whole educational procedure often depends upon whether the child is feeble-minded or not; and in the case of any child, it is impossible intelligently to plan his future and to decide upon the best educational methods unless the child has first been properly classified as regards his degree of brightness. The Lowest Degrees of Brightness. — Definitions in Terms of Social Status. — Until recently, the classification of children was in a chaotic condition. Particularly in tlie case of normal and supernomial children little effort was made to distinguish the different grades. These children were left to look out for themselves. It was only in the lower grades, where the educational and social probleins were acute, that the need for classification appeared imperative. Here effort centered upon the distinction THE LOWEST DEGREES OF BRIGHTNESS 43 between the normal and the mentally defective, and between the various grades of the mentally defective. Until the introduction of the Binet tests, the most widely accepted definitions of mental defectiveness and its degrees were those suggested by the Royal College of Physicians in London, and adopted by the Royal Commis- sion on the Care and Control of the Feeble-minded.^ These definitions distinguish three degrees of mental defect, namely, idiocy, imbecility, and feeble-mindedness. The feeble-minded person, the highest of these three grades, is defined as " one who is capable of earning a living under favorable circumstances, but is incapable, from mental defect existing from birth, or from an early age, (a) of competing on equal terms with his normal fellows; or (b) of managing himself and his affairs with ordinary prudence." The imbecile, a grade below the feeble-minded, is defined as incapable of earning his own living, but able to guard himself against common physical dangers; the idiot, as unable to guard himself against common physical dangers. These definitions are not only indefinite, but they could not be applied very well to chil- dren. For feeble-minded children, another definition was framed : They are " those children who, not being imbecile, and not being merely dull and backward, are, by reason of mental defect, incapable of receiving proper benefit fronl the instruction in the ordinary public ele- mentary schools, but are not incapable by reason of such defect of receiving benefit in special classes or schools." These definitions of the British Royal Commission emphasize the social aspect of mental defect. There is little doubt that social inefficiency is the most important * " Royal Commission on the Care and Control of the Feeble- Minded." Reports and Minutes of Evidence, 8 vols., 1908. 44 BRIGHTNESS AND DULLNESS practical manifestation of the condition. In an adult, social inefficiency means inability to conduct one's self without the guardianship of another, and inability to perform work sufficiently remunerative to supply one's needs. An adult of the highest class of the mentally defective can support himself, but only under favorable circumstances. In a child, social inefficiency means pri- marily inability to profit from the ordinary classes of the public schools. The social criterion of mental defective- ness calls attention to an important aspect, but beyond that it is vague. Moreover, social incompetence may be due to other causes than mental weakness.^ Definitions in Terms of Mental Age. — Accurate defini- tion was clearly impossible without the aid of mental measurement. Binet and Simon gave the world a means for defining in their scale for measuring mental age. The possibility of measuring mental age having been estab- lished, tentative definitions of mental defectiveness and its degrees, in terms of mental age, were promptly formu- lated by the committee on classification of the American Association for the Study of the Feeble-minded.^ These formulations applied the term feeble-minded- ness to all degrees of mental defect, and then divided the feeble-minded into three classes, as follows : (a) Idiots : Those so deeply defective that their men- tal development does not exceed that of a normal child of about two years. (&) Imbeciles: Those whose mental development is higher than that of an idiot, but does not exceed that of a normal child of about seven years, (c) Morons : Those whose mental development is above that * See Doll, " Clinical Studies in Feeble-Mindedness," 1917, pp. 23-26. '"Report of Committee on Classification of Feeble-Minded." Journal of Psycho-Asthenics, vol. xv, 1910, p. 61. DEFINITION OF DEGREES OF BRIGHTNESS 45 of an imbecile but does not exceed that of a child of about twelve years. The term moron, a Greek word, is a new term,^ adopted upon the recommendation of Dr. Goddard, and now in common use throughout the country. It signifies a person conspicuously lacking in judgment and good sense. The desirability of this new term arose from the fact that the term feeble-minded, which is used in England to designate only the highest class of mental defectives, had long been used in America to include all three classes, so that it seemed best to continue this use, rather than to adopt the English term amentia. A feeble-minded per- son in American usage is an ament in the English; and a moron, in the American usage, is a feeble-minded per- son, in the English. Both countries agree in the use of the terms imbecile and idiot. I shall hereafter follow the American usage. Years of Retardation as a Basis for Definition of Degrees of Brightness. — The above definitions of grades of feeble-mindedness in terms of mental age are only tentative and not entirely adequate. They are workable only in regard to adults, for until an individual is fully matured, we do not know what mental age he may finally attain. To avoid this difficulty, feeble-mindedness has sometimes been defined in terms of years of retardation, found by subtracting the mental age from the chronologi- cal age. It is necessary to remember, however, that years of retardation at an early age are much more serious than at a later one. Thus, a child of four who is three years * It conforms with the term morosis, used over a century ago by Linnaeus to designate the condition of severe feeble-mindedness. Nowadays, to express the condition of a moron, the term moronity is used in place of morosis. 46 BRIGHTNESS AND DULLNESS retarded, and therefore one year old mentally, is far more defective than a child of ten who is retarded a like number of years, and consequently of mental age seven. The for- mer child, by the age of ten, will have a mental age far below seven, very likely one of not over three. In general, the degree of retardation increases as a child becomes older. His normal companions leave him farther and farther behind. This is illustrated by the following diagram (Fig. 2), representing growth in mental age. This diagram is largely schematical, though based on experimental data concerning the decrease in the size of the step from one age to the next as the higher ages are reached. That this decrease actually exists can be easily observed. For example, the difference in mental attainments between a three-year-old and a four-year-old child are plainly greater than that between a fourteen- year-old and a fifteen-year-old. In both cases, it is true, the difference is one year of mental age, but a year of men- tal age at the younger ages means a bigger change than it does at the higher ages. The verdict of common observation in this matter is corroborated by the results of scientific tests. This may be seen by a comparison of the percentages of children passing certain tests. For example, a mental test which fifty per cent, of three-year-olds can pass will be passed by almost all four-year-olds, at any rate, by ninety per cent, of them. On the other hand, it is practically impos- sible to find a test which only fifty per cent, of fourteen- year-olds can pass which can yet be passed by ninety (or even seventy) per cent, of fifteen-year-olds. Considerable actual data exists on this matter. Thus Bobertag, who gave a number of the Binet tests to both seven- and eight- year-old children, found that while the average percentage DEFINITION OF DEGREES OF BRIGHTNESS 47 of seven-year-olds passing the tests was only 45, the aver- age percentage of eight-year-olds was over 76, an increase of over 31 per cent. He then tried the same experiment with another selection of Binet tests upon children aged eleven and twelve. In this case, he found that the per- centage of twelve-year-olds who passed the tests was only 16 greater than the percentage of eleven-year-olds pass- ing. Since the increase in the percentage of children passing the tests is twice as great between the ages of seven and eight as between the ages of eleven and twelve, we are entitled to conclude that the differences in mental ability between the former ages is greater than that between the latter. In general, the difference between two groups of children of different ages, in the percentages passing the same tests, serves as a measure of the differ- ence in mental ability between the two groups. On this basis, it is possible to arrive at an estimate of the size of the step in mental ability between any two ages. It is from such estimates that the accompanying diagram is derived. The diagram shows that the difference between the dull child and the bright one becomes much greater as they grow older. Not only does the difference when measured in years of mental age become greater, but even allowing for the fact, as I have done in the diagram, that a year's mental growth at the higher ages amounts to less than it does at the lower ones, the difference in intelligence still increases with age. This is shown in the diagram by the fact that the three curves become farther apart as they ascend to the right. A small distance between the curves at the age of one or two becomes a large distance at the age of fifteen or sixteen. This means that slight mental retardation at the age of two, when measured 48 BRIGHTNESS AND DULLNESS in terms of years, is as serious as great retardation a the age of fifteen. One year of retardation at two year of age is many times as serious as one year at fifteen year of age. Because a year of mental retardation means dif ferent things at different ages, it is not very convenien to describe the brightness of children in terms of such ; 5 6 7 8 9 10 U 12 13 14 J5 16 17 15 19 dO Chronological A^ — ► Fig. 2. — Growth in mental age. unit. This consideration led to a very helpful proposa by several authorities for the adoption of the " in telligence quotient." Intelligence Quotients. — The intelligence quotien represents a comparison between the intelligence of ; particular child and that of normal children of his owi age. It is the quotient obtained by dividing a child' mental age by his chronological age. It thus expresse a child's intelligence as a fraction of the intelligence tha INTELLIGENCE QUOTIENTS 49 is normal for his age. If he has more intelligence than normal, his intelligence quotient is more than one; if he has less intelligence than normal, it is less than one. For example, if the mental age of a child ten years old is twelve, his intelligence quotient is the quotient obtained by dividing twelve by ten, or 1.2; if his mental age is ten, he is normal, and his intelligence quotient is i.o; but if his mental age is only seven, his intelligence quotient is 0.7. A mental age expresses an amount of intelli- gence, whereas an intelligence quotient expresses a degree of brightness. The worth of an intelligence quotient depends largely upon the extent to which it remains constant throughout the years of childhood. If the intelligence quotient of a child remains constant, there is no other item of infor- mation that is of greater interest to his parents or of greater value in directing his education, for at any age his mental age will be the same fraction of his chronologi- cal age, and we can predict very early just what intelli- gence he will have when he is grown. Thus if, at the age of four, a child's mental age is three and his intelligence quotient is seventy-five per cent., we can predict that at the age of sixteen his intelligence quotient will still be seventy-five per cent, and that consequently his mental age will be seventy-five per cent, of sixteen or twelve. The data at hand indicates that intelligence quotients tend as a rule to remain sufficiently constant for practical purposes.^ We still need many more measurements of the same children at several different ages; for only by such measurements can we determine how often and how ^ Kuhlmann, " What Constitutes Feeble-Mindedness ? " Journal of Psycho- Asthenics, vol. xix, 191 5, p. 232; and Terman, "The Stan- ford Revision and Extension of the Binet-Simon Scale for Meas- uring Intelligence," 191!^ pp. 51-61. 4 50 BRIGHTNESS AND DULLNESS much the quotients change as the children grow older. Such tests as have been made, however, indicate that chil- dren with a high quotient retain that high quotient as they grow older ; that those who are average remain average ; and that those with a low quotient retain their low quo- tient. In the feeble-minded — tliose with very low quotients — there is some tendency for the intelligence quotient to decrease with age. The facts, then, offer little basis for the common hope that a child who is lacking in brightness at an early age will " catch up " later, perhaps by a spurt at the time of puberty. On the other hand, there is every reason to expect that a child of a high degree of brightness will maintain his mental superiority all along the way into adult life. There must of course be some age at which the intelli- gence quotient begins to decrease. This is the age at which the growth of intelligence ceases, beyond which there is no increase in mental age. Now since chrono- logical age, which is the divisor used in obtaining the intelligent quotient, must continue to increase as long as the individual lives, it is evident that when mental age, the numerator, stops increasing, the intelligence quotient must begin to decrease. For example, suppose the mental age of the average person does not increase after the age of sixteen; then an individual who was just normal at sixteen and hence had an intelligence quotient of i.o at that age, would at the age of thirty-two have a quotient of only one-half, since he would at the age of thirty-two still have the same mental age of sixteen, and conse- quently have for his intelligence quotient tlie quotient obtained by dividing sixteen by thirty-two. It may seem curious to speak of the cessation of growth in intelligence before the prime of life, usually INTELLIGENCE QUOTIENTS 51 not reached before the age of thirty-five or forty. This is because people commonly overlook the distinction between capacity and the acquisitions of experience. Intelligence refers only to the former. It means mental power, and not knowledge acquired by the use of that power. It is general ability, not expertness along some one line. The age at which intelligence reaches its maximum is the age at which there is no further growth of such abilities as those of memorizing, of concentrating attention, learn- ing, or reasoning about new topics. It is certain that, for the average individual, this age is below twenty. He may go on acquiring knowledge and wisdom all his life, but he works always with the same mental tools. The cessation of growth in intelligence is so gradual that it has not yet been possible to determine with precision at what age it takes place. There is some evidence, how- ever, that, while individuals vary considerably, on the average they reach their maximum intelligence at the age of sixteen. Evidence is offered by the fact that average persons sixteen years of age have been found to pass the same tests as can average persons of any age beyond six- teen. Or, putting it the other way around, we may say that the average adult has the same mental age as the average sixteen-year-old. For example, the majority of a group, made up of business men of little education, and of high school students over sixteen years of age, were found to have the mental age of sixteen.^ Now if the normal adult does not reach a mental age higher than that of sixteen, how are we to state in terms of mental age the brightness of a superior adult? Since any mental age is defined as that degree of intelligence 'Terman, op. cit., p. 50. 52 BRIGHTNESS AND DULLNESS possessed by the average normal individual of that age, and the average normal individual does not reach a mental age above sixteen, it seems impossible to have mental ages above sixteen. Strictly speaking, it is. The difficulty may be arbitrarily overcome, however, by taking as tests for seventeen-year-old intelligence a set of tests which, can be passed by only a certain percentage of tliose who pass the sixteen-year-old tests. By similar procedure, tests may be established for still higher, theoretical, mental ages. In calculating the mental quotient of an adult, then, one would proceed as usual, except that he would divide the obtained mental age by sixteen, no matter how much above sixteen the chronological age might be. On the whole, the intelligence quotient serves as a fairly satisfactory index of brightness in children. The difficul- ties which it offers with adults do not exist with children up to the age of fifteen or sixteen. One should of course be extremely cautious in making predictions. One cannot say tliat because a child has a mental age of four at six that he will have a mental age of eight at twelve. All that can be said is that at twelve he is more likely to have a mental age of eight than any other mental age. The intelligence quotient can not be expected to remain constant except for the average. Even so, it offers the best basis at hand for the classification of children in regard to brightness. It can be used to describe any degree of brightness from idiocy to genius. Application of Intelligence Quotients to the Definition of All Degrees of Brightness. — Before applying tlie intelli- gence quotient to the definition of various classes of chil- dren, it is necessary first to consider what variation in this quotient exists among children of a given age. Meas- APPLICATION OF INTELLIGENCE QUOTIENTS 53 urements by means of the Binet-Simon scale have clearly established the fact, strongly suspected before/ that there is no gap or sharp line of separation between any two grades of brightness. The distribution of mental quo- tients is the same as that of mental ages.^ At each chronological age, we find children of each degree of brightness from idiocy up to genius. They occur in num- bers which gradually increase as we pass from idiocy to the medium degrees of intelligence, and then gradually fall off again as we pass on up to the highest grade. Because decrease in the number of any class, as we proceed in either direction from the average, is gradual, the boundary lines between one class and another are some- what arbitrarily drawn. Wherever we draw them, there will always be a large number of '' borderline cases." For example, what mental quotient we select as the bound- ary between the feeble-minded child and the " dull but normal '* one, depends merely upon what percentage of the population we wish to term feeble-minded. If we agree to define feeble-mindedness as the dullest one per cent.,^ then we will take as its upper boundary an intelli- gence quotient of seventy per cent., since one per cent, of children have an intelligence quotient of seventy per cent, or below. Admitting the arbitrariness of all definitions, we may tentatively accept the following system of classification. ^ Norsworthy, " The Psychology of Mentally Deficient Children,'' 1906, p. 80. See previous chapter, p. 32. ' See Pintner and Paterson, " A Psychological Basis for the Diag- nosis of Feeble-Mindedness," Journal of Criminal Law and Crimi- nology, vol. vii, 1916, and J. B, Miner, " A Percentage Definition of Intellectual Deficiency," Proceedings^ of the Twenty-fourth Annual Meeting of the American Psychological Association. Psychological Bulletin, vol. xiii, 1916, p. 89. 54 BRIGHTNESS AND DULLNESS Classification of Brightness Degrees Class /. 0." Percentage of all children included " Near" genius or genius Very superior Superior Nomial, or average Dull, rarely feeble-minded Borderline, sometimes dull, often feeble-minded Feeble-minded . Moron Imbecile Idiot Above 1.40 1. 20-1. 40 1.10-1.20 .90-1.10 .So- .90 .70- .80 Below .70 .50- .70 .20 or .25- .50 Below .20 or .25 0.25 (^■75 13.00 60.00 13.00 6.00 1. 00 •75 .19 .06 * I. Q. is a common abbreNnation for intelligence quotient. The above table shows that the majority of children, namely, sixty per cent., belong in the class called normal. Above and below the noniial are the superior and the dull, each composing- thirteen per cent, of the total number. In place of the tenn superior, we could substitute that of bright. In ordinar}^ usage, brightness means superiority, but, as I have explained, the term brightness is needed in order to include all degrees of relative intelligence. Consequently, for brightness in the narrow sense, the word superiority is preferable, because it prevents confusion. There are several classes of children not mentioned iti die table. These are usually not defined with any accu- racy. One of these is the backward class. The term backward would be a useful one to designate children who appear to be dull, but whose dullness, there is reason to believe, is only apparent or temporary. Then the term dull would be used when the inferiority was innate and presumably permanent and the tenn bavkzcard when there was reason to believe that it was only temporary, and would be outgrown. The class called mentally retarded, APPLICATION OF INTELLIGENCE QUOTIENTS 55 and that called subnormal, includes all the classes below the grade of normal. Occasionally one hears the rather ambiguous phrase, dull but normal. This expression is intended to emphasize the fact that the child is not feeble- minded. It means dull but not feeble-minded. In this classification of brightness degrees, it will be observed that the significance of a mental quotient is some- times doubtful. This is indicated in the table in the case of quotients falling between seventy and eighty, and jbetween eighty and ninety. The reason for this is that the exact diagnostic significance of a mental quotient is always doubtful. This is chiefly because of three considerations. First, all systems of tests yet devised are somewhat ambiguous in respect to what they measure. They aim to measure intelligence; but, admitting that they succeed fairly well in this aim, it must yet be conceded that the measurements are not entirely free from error. To meas- ure intelligence, they would have to measure capacity altogether apart from learning, practice, or opportunity, and apart from any effects due merely to the chronological age of the child, that is, to mere maturity. A second consideration is that, entirely apart from the question of what the tests measure, there is always present in a particular case the possibility of a large error in the accuracy of the measurement. It is impossible to be positive in any individual case that the real mental age does not differ considerably from the one actually obtained. This remains true no matter how carefully the tests are given, for there remains the possibility that the particular tests used are not well adapted to testing the intelligence of the particular case at hand. The third consideration affecting the interpretation 56 BRIGHTNESS AND DULLNESS of intelligence quotients is that standards are different in different groups of people. They vary with race, social class, and sex. I shall therefore discuss the effect of each of these. The facts are very interesting and of immense importance in the understanding of social questions. Race, Class and Sex Differences in Intelligence. — The matter of race differences obviously raises important questions. One of these is the age at which the different races reach their maximum development of intelligence. There is some evidence that races vary considerably in this respect. For example, it appears that the aboriginal chil- dren of South Australia complete their growth in intelli- gence several years earlier than do white children.^ ^ Another question is that of types or kinds of intelli- gence. It may be that there are no racial differences in type, so far as general intelligence itself is concerned. But we can measure intelligence only through the perform- ances in which it is manifested; and it is certain that dif- ferent races manifest their intelligence in different ways. If different races show different types of intelligence, or rather, if they show their intelligence in different ways, it becomes necessary to have different sets of tests for dift'erent races. In America, where the race problem is acute, the dif- ference between white and colored children is an inter- esting subject. In an investigation conducted in Colum- bia, South Carolina,^^ it was found that, as we should expect, the majority of white children tested " at age." The largest number of colored children, on the other ^° Porteus, " Mental Tests with Delinquents and Australian Aboriginal Children." Psychological Rcvieiv, vol. xxiv, 1917, p. ^2. " Strong, " White and Colored Children Measured by the Binet- Simon Measuring Scale of Intelligence." Pedagogical Seminary, vol. XX, 1913, pp. 485-513. RACE, CLASS AND SEX DIFFERENCES 57 hand, tested one year below age. It follows, then, that if we take tests that have been standardized for white chil- dren and apply them to colored children the latter will not do so well as the white children. If we use such tests in the diagnosis of brightness, we obtain a very much larger percentage of feeble-mind edness for the colored popula- tion than for the white. Some people, no doubt, would find no objection to this result ; and, in itself, it is extremely valuable information. Yet, whatever we may think of the relative intelligence of the negro and the white man, in diagnosing the case of an individual negro, it hardly seems proper to call him dull if, as a matter of fact, he is a normal negro. Fully as important as race differences are those due to social status. It has been well established that, on the average, children of the " lower '' classes — the labor- ing classes — the wage earners and the men of small busi- ness — have a lower mental age than children of the ** higher " classes — the professional classes, and the suc- cessful business men, always providing that the chrono- logical ages are the same. One interesting study of this highly important matter was conducted by the school teachers of Breslau, Ger- many. This city maintained two elementary public schools, one called the Vorschule and the other the Volk- schule. The Vorschule was attended by children of the higher social classes, whereas the Volkschule was made up of children of the laboring and lower business classes. Children could enter the gymnasium, with its nine-year curriculum preparing for the University, after three years of preparation in the Vorschule, but only after four years in the Volkschule. Now, upon the demand for a common school for all classes to replace the Vorschule and the S8 BRIGHTNESS AND DULLNESS Volkschule, an investigation was made of the intelligence of children in the two schools by means of a revision of the Binet scale. It was found that the children of the select Vorschule did much better than those of the Volk- schule, nine-year-old boys in the former attaining the average of ten-year-old boys in the latter.^ ^ In the United States, the situation is similar to that in Breslau. For example, in Cambridge, Massachusetts, a comparison was made of children in the kindergarten and first grade of two schools, one of which was located in a " good " neighborhood and the other in one of the poorer sections of the city. Six-year-old children from the good neighborhood were found to do better than seven-year-old children from the poorer one.^^ Another investigation consisting of a study of the brightness of children according to the occupation of their fathers was made in Columbus, Ohio.^^ The results obtained are summarized in the accompanying table. On the whole, the data at hand indicates that the dif- ference in brightness between children of tlie lower and upper classes is marked. The difference increases with the age of the children, until at the age of fourteen the children of the superior classes are about one year of mental age in advance, and those of the inferior classes about one year of mental age behind, the average. ^^ " Hoffman, " Vergleichende Intelligenzpriifungen an Vorschiilern und Volkschiilern." Zeitschrift filr Angewandte Psychologie, vol. viii, 1914, pp. 102-120. " Yerkes and Anderson, " The Importance of Social Status as Indicated by the Results of the Point Scale Method of Measuring Mental Capacity." Journal of Educational Psychology, vol. vi, 1915, pp. 137-150. "Bridges and Coler, "The Relation of Intelligence to Social Status." Psychological Review, vol. xxiv, 1917, pp. 1-31. " See Terman " The Measurement of Intelligence," p. y2. RACE, CLASS AND SEX DIFFERENCES 59 Mental Age of Children According to Social Status of Parents Social status Professional : Profess- ors, doctors, law- yers, editors Salesmen : Including insurance and real estate Proprietors: Also managers, officers and contractors . . . , Clerical workers: Clerks, boolckeep- ers, accountants, cashiers Skilled laborers: Mechanics, metal workers, building trades . . Unskilled laborers. . . Teamsters No. chil- dren tested 32 39 34 17 63 60 18 Chronological 7 yrs. 3 mos. 7 yrs. 6 mos. 7 yrs. 10 mos. 7 yrs. 10 mos. 8 yrs. o mos. 8 yrs. o mos. 7 yrs. 10 mos. Mental age 9 yrs. 8 mos. 9 yrs. 2 mos. 9 yrs. I mo. 9 yrs. I mo. 7 yrs. 10 mos. 7 yrs. I mos. 7 yrs. o mos. Intelli- gence quotient 1.33 1.22 1. 16 1. 16 .98 .89 .89 Similar conclusions have been reached regarding the school success of children. One study, made in Pitts- burgh, finds that fifty per cent, of the children who are well advanced in their school work come from homes which have telephones, and that only nineteen per cent, of those who are below grade come from such homes. ^^ If we can consider a home's possession of a telephone of any value as an index of its economical standing, clearly those children coming from the homes financially com- fortable do better in school than those from poor homes. This finding agrees perfectly with the fact that children from better homes have a higher level of intelligence. " Kornhauser, " The Economic Standing of Parents and the In- telligence of Their Children." Journal of Educational Psychology, vol. ix, 1918, pp. 159-164. 6o BRIGHTNESS AND DULLNESS Besides a child's race and social class, we have to take into consideration his sex. There is a slight difference in type of intelligence between boys and girls. The boys seem to excel in some tests and the girls in others. The latest studies indicate, moreover, that girls are slightly superior to boys in brightness at all ages from the very earliest up to fourteen. The difference is slight, and amounts, at most ages, to not more than three or four per cent. Up to the age of fourteen, the intelligence quotient of boys standing at the middle of their age group is usually about ninety-seven or ninety-eight per cent, whereas that of girls at the middle of their age group is one or two over one hundred per cent.^'^ In spite of all these complications, the intelligence quotient affords a very useful and easily understood medium for the expression of a child's brightness. It should never be regarded as a mathematically exact diag- nosis of mentality. It is but one item, and needs careful interpretation, not only in the light of the child's race, social class, and sex, but also in the light of his physical condition and his entire past history. " Terman, op. cit., pp. 62-83. CHAPTER IV BRAINS The Relation of Mind to Body. — One of the striking features of modern psychology is the attention given to the relation of intelligence to the bodily organism. An extremely close connection has been found between the activity of the body and tliat of the mind. This connec- tion is due primarily to the inseparable association of the mind with that part of the body, enclosed within the upper portion of the skull, known as the brain, or cere- brum. The brain is connected with the rest of the body through the nervous system, of which it is a part, and through the circulation of the blood. Intelligence is con- nected with the body as a whole, but solely through the agency of the brain, so that the most fundamental of the relations of intelligence to the body is its relation to the brain. This relation is discussed in the present chap- ter. The relation of intelligence to other bodily fea- tures and to general physical development will be discussed in the two following chapters. It is a well-established fact that all mental processes are dependent upon accompanying brain processes. No mental process can occur without a corresponding brain process; no sensation can be felt, no object can be per- ceived or remembered, and no problem solved through the aid of judgment and reason excapt through the function- ing of the brain. In view of this intimate association of all mental processes with brain processes, we should expect to find a close parallel between Intelligence and brain 6i 62 BRAINS development. Many able scientists have investigated the matter. They have sought to find out just what are the differences between the brains of beings possessing differ- ent degrees of intelligence. A great deal more work needs to be done to make our knowledge definite and complete in detail, but the main features of the correlation be- tween brain and intelligence are beginning to be fairly w-ell established. The Relation of Brain Development to the Evolution of Animal Intelligence.— The relation of the brain to intel- ligence may be studied in various ways. Most studies have dealt either with brain weight or with brain struc- ture, particularly with its minute structure as revealed by the microscope. Of these two types, the latter has proved much the more enlightening ; but both are valuable. Both types of investigation have been made on animals, on children and on adults. Those on children deal with the changes that occur in the brain wath growth in in- telligence, and it is with these that we are most concerned. The studies on animals and adults, however, also de- serve attention. Examination of the brains of animals, as we follow the path of their evolution from those of lowest intelli- gence up to man, discloses a direct relationship between the development of the brain of a species and its intelli- gence. This relationship is show^n in the increased w^eight and the increased complexity of structure of the brains of the higher animals. Concerning brain weight, little needs be said. It Is directly related to Intelligence, but only in a rough w^ay, and only after corrections are made for a number of factors such as body w^eight, proportion of fat, and size of the skeleton. - "Studies of the microscopic structure of the brain deal EVOLUTION OF ANIMAL INTELLIGENCE 63 mainly with the structure of its outer shell. This shell, called the cerebral cortex, is known to be the part of the brain, or cerebrum, most intimately associated with the operations of the mind. It contains millions of nerve cells, called neurones. Each of these neurones has a large cell body from which extend a number of branches or fibres, which connect the cells with each other and with other parts of the nervous system. The neurones are arranged in several more or less distinct cortical layers, of which the thickest are the pyramidal layers, so called because they contain cell bodies which are shaped like pyramids, with their apex pointing towards the brain's surface. There is considerable evidence that these pyra- midal layers are the ones which are most closely con- nected with the higher mental processes. Besides the pyramidal cells, there are numerous other types, most of which are shown in Fig. 3. Ascending the scale of vertebrates, an investigator finds a number of very decided changes in the cerebral cortex. There is an increase in the number of distinguish- able layers of neurones and an increase in their thickness. At the same time there is an improvement in the structure of the individual neurones. The cell bodies of the neu- rones acquire a more finished appearance and show a marked increase in the number and length of the fibres branching from them.^ The differences in the cortex between the lower and the higher animals are most decided in the case of the pyramidal layer. The increase in thickness is far greater in this layer than in the others. This layer in the dog IS one-half as thick as in the monkey, and in the monkey * Ramon y Cajal, Revue Scientifique, 4th series, vol. iv, 1895, p. 706. // /// tv Pig. 3. — Diagrammatic representation of the COTtical layers and of the different t^^pes of neurones. (After Starr, Strong and Leaming, "Atlas of Nerve Cells," 1896, p. 72,) /, superficial layer; //, layer of small pyramidal cells; ///, layer of large pyramidal cells; / F, deep layer; F, white matter made up of connecting fibres. EVOLUTION OF ANIMAL INTELLIGENCE 65 it is three-fourths as thick as in the human being. *' As a very rough analogy," writes Bolton, " the pyramidal layer of the dog may be compared with that of a still- bom infant; and the pyramidal layer of the rheisus (monkey) with that of an imbecile." ^ He claims that very striking differences between man and the animals exist in the pyramidal layer of the anterior portion of the cortex known as the frontal lobes. The pyramidal layer of the higher animals differs from that of the lower ones, not only in its greater thickness and the greater number of its component cells, but also, far more than does any other layer, by the degree of development of its cells. Development of a nerve cell can be followed by the increase in the size of the cell body, and change in its shape and texture, and also in the number and length of its fibres. Great variation exists in the degree of development of the pyra- midal cells in different species. In lower species, the development of these cells is very rudimentary, and even in the adult brain of these species they show little change from their primitive embryonic condition. That the degree of development of the individual cells is as important as the thickness of a cortical layer, is well illustrated in the guinea-pig. The guinea-pig's intelligence is of a low order; yet the animal possesses a pyramidal layer of considerable thickness. According to the observations of Watson, however, the cells of this layer in the adult are advanced but little beyond their condition in the new-born animal, and development in most cases is so incomplete that it is difficult to credit I ± .i » ». 1 1 ' — — — — — — -"^ — '■ ■ ■ ' ' ' " ' " A Contribution to the Localization of Cerebral Function, Based on tlie Ginico-Pathological Study of Mental Disease." Brain, vol. xxxiii, 1910, pp. 106-115. 66 BRAINS them with much functional vahie. This similarity between the pyramidal layer of the adult and the new-boni animal, writes Watson, '* affords a ready explanation of Miss Allan's observation that there is in the case of the guinea- pig" no increase in complexity of psychological processes after the third day of life. It also affords a striking example of the fact that actual depth alone of a cortical layer is not to be altogether relied upon, when endeavoring to compute the functional significance of such a layer." ^ Thus, from the study of the weight as wxll as the microscopic structure of the brain, it is evident that the intelligence of an animal species depends upon its brain development. The higher animals have a greater relative brain weight and a better developed cortex. The cortical layers, particularly the pyramidal, are thicker and contain more numerous and better developed cells. The Development of the Brain in Children. — It has long been established that the stages in the development of a human being run roughly parallel to those in the evolution of animal species. Consequently, we should expect to find that changes occur, in the brain of an indi- vidual human being as he develops into an adult, similar to those met with in passing from the lower animals to the higher ones. This expectation, we shall find, is entirely justified. As regards the changes iia the brain which occur with the growth of the human child, we have to consider again both brain weight and microscopic structure. European cases furnish tlie most reliable and extensive data on increase in brain weight. Dr. Richard Scammon, profes- ' " The Mammalian Cerebral Cortex, with Special Reference to Its Comparative Histology." Archives of Neurology, vol. iii, 1907, pp. 49-117. BRAIN DEVELOPMENT IN CHILDREN 67 sor of anatomy in the University of Minnesota, has recently gone over all the existing data with great care. On the basis of all reliable material, excluding cases of disease known directly to affect brain weight, he has con- structed a curve of brain growth which is probably the most accurate ever drawn. This curve, as yet unpub- lished, he has very kindly furnished me, and it appears in figure No. 4. The irregularities in the curve at the higher ages in all probability have no significance. They are due simply to an insufficient number of cases and the fact that the weights for different ages are necessarily those of the brains of different children. The curves of growth in brain weight show some points of very great interest. The most striking thing about the growdi of the brain is the very early age at which the greater part of it is completed. Even at birth, the brain is relatively large. It has already attained the fourth part of its final weight, whereas most of the organs of the body at birth have only the tenth to the fourteenth part of their ultimate weight. During the first year of life, the brain grows much more rapidly than at any later time and increases two and one-half times in weight. During the next few years, it continues to grow at a reduced but still rapid rate, until hy the middle of the fifth year, it has reached over ninety per cent, of its final weight. After the age of five there is only a very small increase, which takes place very slowly, and which is completed at the age of fifteen. According to Scammon, there is probably no increase in brain weight after fifteen years, and in some cases the entire adult brain weight is acquired by the seventh year. A period of increased brain growth at puberty has been described, but Scammon*s 68 BRAINS examination of practically all tlie published data on brain weights in children fails to confirm this observation. 1500 10 11 [I O 14 15 le 400'- 300- m 100 J L T I — I — I — I — r 1 L L J L J L 1 £ 3 4 5 6 7 ft 9 10 U 12. 13 H 15 IS Age inYeara — > Fig. 4. — The growth of the brain in weight (by Idndness of Dr. Scammon). The continuous line is the curve for boys and the dotted line the curve for girls. A feature of the cerebrum of children which is quite distinctive in tlie relatively poor development of the BRAIN DEVELOPMENT IN CHILDREN 69 frontal lobes. In the new-born child these lobes are comparatively inconspicuous, and consequently have a greater growth to accompHsh after birth than have the other parts of the cerebrum.* The fact that the brain completes such a large propor- tion of its total growth during the first few years of life explains why it is that feeble-mindedness always appears, if at all, at a very early age. Although most feeble- minded children are born so, it is known that a consider- able percentage become feeble-minded after birth. But it is a remarkable fact that no child ever becomes feeble- minded after the age of four of five, the age at which the brain reaches almost its full weight. Now if the brain of a child who is not born feeble-minded is well nourished during the first four or five years, by that time it will have completed most of its growth. At that age, then, he is comparatively safe, for his brain will already have developed into whatever is in keeping with the potentiali- ties present at birth. It cannot be too strongly emphasized that the really critical years of a child's life are the years before he enters school. The age of puberty is often spoken of as a critical period, and no doubt it is; but it is incomparably less critical than the first few years of life. There is strong evidence indicating that the level of brightness of a child is determined during these years, whether he be dull or normal. This is indicated by a tendency on the part of intelligence quotients to remain constant after the age of five, or earlier. As long as an intelligence quotient remains constant, the brightness of the child is not changed, for, as the preceding chapter explained, bright- * Pflaunder and Schlossmann, " The Diseases of Children," 2d edition, 1912, vol. iv, p. 124. 70 B1>L\1NS ncss is nirasuivd hy the intelligence qnotient. Now the constancy oi intellii^ence (jiioticnts may he far from per- fect ; hnt. it is i^ieat enini«;h to indicate thai the htij^htness of chilihen, in the i;reat majority of eases, is snhstantially lixetl hefore they ever enter school. Brightness, then, appears to (lepiMid solely npon heredil\' aiul the proper completion oi those hrain chani;es which are rellected in i;ro\vth in hrain weight ; and these hrain, chan5;es, as Dr. Scammon's cm^ve shows, are ptaclically completed hy the ai;e o\ live. iMnMher relations helwcen hrain weight and intelli- gence come io lii^ht if we compare their i;rcnvth cnrves. C'm"vcs i.)i i;ro\vth in intelligence, slunvini;' the increase in intellij;ence with chronological ai;e, are «;ivcn in the pre- ceding' chapter.'' The i;ri)\\ th cnrves for intelligence and brain weii;ht ai^ree in slunvini;- a. mnch more raj)id rise in the tirst few years than in the later years. They ai;ree also in that In^th Inn'ome i>ractically le\el at ahont the a^e ol tifteen ov sixteen. The intellii;ence enrve, however, dif- fers from the hrain em-ve in that it ccMitinnes to rise considerably, loni;- after the brain cnrve has become prac- tically level. There are two pc^ssible explanations for this dilTerence. (^ne is that in reality the two cnrves shonld correspontl, bnt that they dit not bccanse i>nr methods of mcasnrini;- intellii;ence are so lari;ely inlhienced bv learnini;-. h^-om this point c^f view, it mis^ht be allei;etl that what we chart beyond the ai;e oi t"ive as a i;"rowth in intellit;ence is merely the elTect oi practice and experience in increasini;- the success achieved with an intelligence already tWed. at least in rei;ard io nine-tenihs o[ its Ihial valne. The other explanation is that the growth shown by the intellii;ence cnrve in the later years of childluHHl ' See page 4^ BRAIN DEVELOPMENT IN CHILDREN 71 has its brain counterpart in certain microscopic changes in the cortex which are not reflected in brain weight. Here, however, we would have to distinguish carefully l^etween the brain changes corresponding to learning, which con- tinue at a good rate throughout life, and those corre- sponding to growth of intelhgence, which certainly come very nearly to a stop at an age not much beyond sixteen. Between these two explanations it is not now possible to decide with certainty; but in all probability the latter is nearer the truth. We may now turn to the microscopic structure of the brain and consider the changes it shows as the child grows older and more intelligent. Studies in human embrycjlogy indicate that after the third or fourth month of f(jcital life, the numl>er of cells in the cerebral cortex does not increase. Their number, then, is determined well before birth. It follows that the growth changes shown by the microscope consist chiefly either in increase in the size, and change in shape and texture of the cell-lx)dies, or in the number and structure of the fibres. The cell-bodies at birth are denser and smaller and lack somewhat the profuseness of fibres characteristic of the adult cortex. They are also lacking in a certain pigment which they later acquire. Many of them, particularly the pyramidal cells, have not yet attained their characteristic shape. They appear embryonic and imperfectly formed. As the child grows older, the cortical nerve fibres acfjuire an enveloping sheath. The significance of this sheathing process, however, is not well understood. It is supposed to aid in the conduction of the nervous impulse along the fibres. The aquisition of sheaths on the part of the cortical fibres continues through middle life; accord- ingly it probably has little to do with the determination of ^,2 BRAINS the individual's brightness or the fundamental powers of his mind. It appears rather to be correlated with the learning and knowledge that come with experience. Though very few systematic studies have been made of the changes in the cell structure of the cortex that occur with increase in age, it has been established that the most significant development is that which occurs in the pyramidal layer. The cortical layers lying below the pyramidal complete their development very early. In the six months' foetus they are as thick as at birth and very nearly as thick as in the adult. The pyramidal layers, on the other hand, are only one-half as thick in the six months' foetus as at birth and only one-third as thick as in the adult. It is in the thickness of the pyramidal layers that the cortex of man differs most from that of the lower animals; and it is here that we find the greatest difference between the cortex of the new-born infant and the adult. The fact that the pyramidal layers, which are so poorly developed in the new-born child and in the lower animals, are the ones which are the slowest to reach maturity in the human being, is regarded as evidence that these layers are the ones most closely associated with intelligence. The pyramidal layer, to quote from Watson, *' subserves the higher associations, the capacity for which is shown in the educability of the animal. It has therefore to do with all those activities which it is obvious that the animal has acquired or perfected by individual experience, and with all the possible modifications of behavior which may arise in relation to some novel situation, hence with what is usually described as indicating intelligent as apart from instinctive acts." ^' ® *' The Mammalian Cerebral Cortex, with Special Reference to Its H^stolog}^ I. Order Insectivora." Archives of Neurology, vol. iii, 1907, p. no. BRAIN AND INTELLIGENCE IN ADULTS 73 The Relation of the Breiin to Differences in Intelli- gence in Adults. — In confirmation of the results obtained by the study of animals and of the growing child are those obtained from the comparison of persons of differ- ent degrees of brightness. The brains of lower and higher animals, as we have seen, differ as regards certain features of their brains in the same manner as do younger and older children. Now if these features really are those which correspond to intelligence, then we should find a marked difference in these same features upon com- paring the brains of persons of widely different levels of intelligence. Brain weights of adults have been determined both for normal individuals and for men of great eminence. The normal male brain has a weight averaging something over 1360 grams. The extreme range, if we exclude idiots, is probably l:>etween 1000 and 2000 grams with the majority of cases falling" between 1300 and 1500 grams. The weight of the female brain is about 10 per cent, less than that of the male. However, when the weight of the female brain is taken in proportion to physi- cal development, as shown by the weight of the body and the skeleton, it is greater than that of the male. Thus neither sex can claim preeminence from the point of vie\V of cerebral development. The relation of brain weight to physical development in the female is somewhat like that in an undersized male; for in either sex, the smaller the stature, the greater is the relative brain weight. A comparison of the brain weights of normal men with those of eminently able men is not uninteresting. A number of great men have realized the value to science of post-mortem examination of their brains and have therefore directed that their brains be made available for 74 BRAINS study. The brain weights of over one hundred of these men have been determined. They range from about 1200 to 2000 grams, thus overlapping the range of brain weights of ordinary men. On the average, however, they weigh about 1470 grams ; "^ that is, over one hundred grams more than the average of ordinary individuals. The brain- weights of some of the well-known men is given in the following list: Grams Cuvier, naturalist 1829 Thackeray, novelist 1658 Spurzheim, anatomist and phrenologist iS59 Daniel Webster, statesman 1516 Agassiz, naturalist 1495 Grote, historian 1410 Bertillon, anthropologist 1398 Liebig, chemist 1352 Gambetta, statesman 1294 The brains of exceptionally intelligent men tend to average greater in weight than those of ordinary men, and those of the feeble-minded average less. It has been observed that a brain weight below about 1000 grams is seldom found with an intelligence above the grade of feeble-mindedness. The average brain-weight of adult idiots is probably not over 1200 grams. It should be emphasized, however, that a very large and heavy brain is not incompatible with idiocy. Its size may depend mainly upon an overgrowth of non-nervous tissue at the expense of the nerve cells, or it may be due, as in hydro- cephalus, to the accumulation of a large amount of fluid within the brain cavities. Although a rough correlation between brain-weight ^ Spitzka, " A Study of the Brains of Six Eminent Scientists." Transactions of the American Philosophical Society, 1907. In this paper are gathered together all previous data on the brain-weights of eminent men. BRAIN AND INTELLIGENCE IN ADULTS 75 and intelligence evidently exists, it is not close enough, in different individuals, to indicate that brain-weight in itself is the important factor. The reason for this is obvious, v^hen we remember that only two per cent, of the brain is composed of nervous tissue. The rest is made up of the cells of supporting tissue, of blood- vessels, and of fluid. The real anatomical basis of intelli- gence, without doubt, is found only in the strictly nervous tissue of the brain cortex. In the study of the relation between the microscopic structure of the cortex and intelligence, efforts have cen- tered on determining the difference between the normal brain and that of the feeble-minded person. One of the earliest investigations, as well as one of the most careful and elaborate, is that of Hammarberg. This Swedish scientist, who died at an early age and before his great work^ was published, made careful microscopic studies of the brains of normal and feeble-minded persons, con- cerning whose intelligence during life he had fairly accurate data. His drawings, some of which are repro- duced in figure No. 5, show only the cell bodies, and not the cell fibres. They clearly demonstrate the striking correspondence between mental deficiency and deficiency in the number and size of the cell bodies. The drawings represent for both normal and feeble- minded individuals the appearance of thin sections of the cortex as seen under the microscope. Sections la, Ila, and Ilia, are from three different localities in the cortex of a normal man, a merchant, who died from abdominal typhoid at the age of twenty-eight. Beside each of these sections are sections of the same localities from the brains of feeble-minded individuals. Section Ih shows the cor- '"Studien iiber Klinik und Pathologic der Idiotic," 1895. 76 BRAINS ■i I 1 ' t • ' >'., w l\\i ■vi- ', \- ■Hi o lb Ic i ila a. ii lib !/' ;■>» A Ilia lei* II 'I .1 / lllb Fig. 5. — Comparison of sections of the cortex of normal and feeble- minded persons, by drawings of the cell-bodies (after Hammarberg). la, Ila, Ilia, normal; lb, imbecile; Ic, lib, Illb, idiot. BRAIN AND INTELLIGENCE IN ADULTS 77 tex of an imbecile, aged one year and ten months, and Ic that of a twenty-two-months-old idiot, in the same cortical region as that represented in section la. The sec- tion of the imbecile brain, Ih, according to Hammarberg, resembles that of a normal child during the first year of his life. That of the idiot, Ic, corresponds in development to tliat of a normal child between the sixth foetal month and the beginning of the first year of life. Sections Ilh and I lib are taken from the same localities of the brains of idiots as II a and Ilia. Section Ilh is from the same brain as Ih. Section Illh is from the cortex of an idiot who died at the age of fourteen. The greatest portion of this cortex, Hammarberg states, was not more developed than the normal cortex in the last part of embryonic life. It has been noted by Bolton and others that the cells of the feeble-minded cortex are undeveloped.^ Their small size and the great scarcity of their fibrous branches show this. In the pyramidal layer, the cells, though well outlined, are lacking in angles, and so appear globular and poorly formed. Such poorly formed cells may be found in all parts of the cerebral cortex, but they are most frequent in the anterior part of the frontal lobe. Similar cells were noted by Bevan Lewis in the cortex of the ape. Since the lack of development of the cells involves a scarcity of fibrous branches, or association fibres, it fol- lov/s that in the feeble-minded cortex there is a marked shrinkage in the bands of association fibres. Indeed, it is quite possible that the scarcity of fibres rather than the underdevelopment of the cell bodies is the fundamental cause of mental weakness. The underdevelopment of the fibres and of the cell body are, however, both parts of the 'J. S. Bolton, "The Brain in Health and Disease/* 1914, pp. 79-99- 78 BRAINS general underdevelopment of the cells as a whole, and both are most obvious in the front part of the brain. According to Bolton it is only in this frontal region that the degree of underdevelopment varies strictly in accord- ance with the grade of feeble-mindedness. Bolton believes that differences in the intelligence of normal individuals are due to variation in the same cortical features as those by which feeble-mindedness is so clearly shown. ''As a final remark," he writes, " I would add that there is reason to believe that this physical basis of the cerebral functions . . . exhibits equally import- ant though less extensive variations in the cases of pre- sumably normal individuals ; and thus indicates the likeli- hood of a structural origin for individual differences in mental endowment." ^^ This opinion is unquestionably sound. It being established that an underdeveloped cortex is the cause of feeble-mindedness, it is safe, even in the absence of post-mortem examinations, to conclude that it is the degree of development of the cortex which deter- mines the degree of intelligence of any individual. Aside from the deficiencies revealed by the microscope in the brains of the feeble-minded, there often exist gross defects of structure of such a severe and extensive nature as to be obvious to the naked eye. Important structures may be entirely absent. There may exist great divergen- cies from the normal configuration of the cortical folds or convolutions and the fissures between them. The con- volutions are likely to be fewer in number and less com- plex, so that the brain presents a simpler and smoother appearance. Often the cortex is reduced in thickness. Great bands of association fibres running beneath the cortex may be entirely absent. I once sectioned an idiot's " Op. at., p. 99. BRAINS AND INTELLIGENCE IN ADULTS 79 brain in which the great band of association fibres con- necting the two cerebral hemispheres was almost entirely absent. The cortex itself was very much thinner than in the normal brain. In the small headed cases, called microcephalic, such as are sometimes exhibited in '' side- shows " as the '' last of the Aztecs," the brain cortex is greatly reduced in area. These specimens, as a rule, show a narrow, rapidly receding forehead which corresponds to the underdevelopment of the temporal and frontal lobes. In the back part of their brains, however, the insufficiency in the amount of cerebral cortex is still more noticeable. f^ Although these gross malformations of the brain are frequently associated with the more serious degrees of mental deficiency, they are not so important as the defects that can be seen only by the aid of the microscope, and they should not be regarded as the essential basis of imperfect mental development. There are many instances on record in which just such gross malformations have existed in individuals whose mental condition was appar- ently normal.^ ^ It is now established beyond all doubt that the really essential basis of defective mentality is defective development of the cerebral neurones. " What- ever may be the relation of mind to brain," writes Tred- gold, " it is now fully recognized that the manifestation of mental activity is indissolubly connected with the cells of the cerebral cortex. Mind develops pari passu with their growth, and fails with their decay. Dementia is coincident with their degeneration and death, and amentia (feeble-mindedness) is associated with their incomplete development." ^^ Summing up, then, the salient points concerning the " See Tredgold, " Mental Deficiency," 2d ed., p. 74. "0^«7.,p.73. 8o BRAINS relationship between brain development and intelligence, through the evolution of the lower animals and the growth of the human being, we find Nature utilizing throughout the same fundamental principles. Thus, in all strata of development, the correspondence depends to some extent upon brain-weight, but mainly upon the complexity of structure displayed by the cerebral cortex. In animals and people, advancement in intelligence is accompanied by increased number and improved size and structure of the pyramidal cells, with richness of connecting fibres. The chief fact to be carried from this part of the discus- sion to the perusal of succeeding chapters, is that the men- tality of a child is based, primarily, upon the development of his cerebral neurones. CHAPTER V PHYSICAL DEFECTS The Relation of Physical Defects to Intelligence. — I have discussed the relation of intelligence to brain development somewhat in detail because it is funda- mental. But the development of the brain does not occur independently of the rest of the physical being. The brain, like all parts of the body, is dependent for its nutrition upon the food we eat and the air we breathe, and so is dependent upon the processes of digestion and of respiration. And for the nervous currents which stimu- late it to action, the brain is dependent upon the sense organs and the nerves which connect it with them. In turn, the brain exerts a far-reaching control over the body. It controls the movement of the muscles in the execution of acts, and it exerts a powerful influence over many of the internal bodily processes, such as those of secretion, diges- tion, circulation and respiration. Not only is the brain connected with the rest of the body through this mutual dependence of functions, but also through the fact of a common origin. All parts of the body develop from the same germ cells. It is therefore not surprising to find that many bodily defects are very frequent in mentally retarded children, and that, on the other hand, a well- developed body is something of an index of intelligence as well as an aid to its development. The correlation between intelligence and physical defects is not so close, however, as many people have 6 81 82 PHYSICAL DEFECTS supposed. Ayres conducted an investigation in New York City to determine the relation between the degree of mental development as shown by school attainments and such defects as adenoids, enlarged tonsils and glands, defective teeth, poor vision, and poor hearing.^ The children were divided into two groups, normal and retarded. Those who were in the grade they should have been in, had they entered school at the age of six or seven and progressed at the rate of one grade per year, were called normal, and those who were behind their grade were called retarded. The comparison was thus between the older children in a grade, the retarded ones, and their younger classmates, the nonnal, ones. The outcome was that the percentage having physical defects Avas larger for the normal children than for those who were retarded ! In order to find an explanation of this unexpected result. Ayres retabulated his data, classifying all the chil- dren by their ages instead of by their school grade. It thereupon appeared that there exists a steady decrease from the age of six up to the age of fifteen in the per- centage of children having each sort of defect, with the exception of bad vision. This explains the presence of more physical defects among the normal children than among the retarded. The nomial children were younger than the retarded children of the same grade •with whom they were compared, and consequently showed more defects. Ayres, still using the same data, proceeded to make a comparison, not between normal and retarded children in the same grade, but, for children of each age, be- tween those of higher and lower grades, thus eliminat- ing the influence of age upon the comparison. Children * Ayres, "Laggards in Our Schools," 1909, pp. 1 17-132. PHYSICAL DEFECTS AND INTELLIGENCE 83 of the same age were divided into superior, normal and dull, aeeording to whether they were advanced, average, or retarded in their school grade. It then appeared that the percentage having physical defects was larger for the dull children than for the superior. The difference in the percentages of physically defective children in the three classes — dull, normal and sui)crior — was slight, but the difference in the degree of defectiveness was found to be rather marked, the dull child showing on the average considerably more defects than the superior one. Ayre's investigation shows, then, that in general dull children are more likely to have physi- cal defects than are superior ones, and that the defects in the dull child tend to be more numerous and more serious than those in the superior child; but it also brings out the fact that the difference between dull and superior children, so far as physical defects are concerned, is less than that between younger and older children. Now, although the degree of correspondence between intelligence and freedom from physical defects is slight, physical defects exert a marked influence upon the activ- ity of intelligence. A child with physical defects may l)e either superior or dull; but, whichever he is,, the removal of his physical defects will help him mentally. Physical defects, of little importance as causes of poor intelligence, and, only in small part due to the same fac- tors as dullness, nevertheless constitute a severe handicap to efficient mental activity, causing the child to do his mental labor under difficulties. They affect intelligence somewhat as hamperin.cf clothing does the efficient exercise of physical strength. There mip:ht be only a slight corre- lation with the weight or fit of a child's shoes and the strength of his legs; yet a child with sufficiently heavy 84 PHYSICAL DEFECTS and misfitting shoes would certainly be handicapped in a foot-race. The proper treatment of physical defects is an import- ant educational measure, a measure that enables the child to make the best use of his abilities. Removal of a child's adenoids, or the provision of proper eye-glasses, may be of greater importance to his mental achievements than the difference between the best and worst of school teach- ing. I may say that the presence of remedial physical defects in an apparently dull child is an almost hopeful sign; it allows his parents to believe that his dullness is only apparent — that his intelligence is normal but handi- capped. There are many striking cases on record of improvement in a child's school work as the result of the removal of adenoids or tonsils, or the fitting of glasses, followed by special, individual teaching.^ The account here given of sensory and other defects is limited to the minimum that is compatible with a broad understanding of the educational needs of children. I shall point out merely how the presence of the commoner defects, particularly those of vision and hearing, may be ascertained and indicate some of the chief ^consequences. Defective Vision. — Visual acuity, or the ability to see, is ordinarily tested by having the child read letters at a distance. These letters are printed in nine lines on a chart, the letters of each line being smaller than those of the line above it. Such a chart is commonly known as a Snellen test card, and may be procured from any oculist. Usually the top line contains just one letter, which is of a size ordinarily distinguishable at a distance of 200 feet. ^See Witmer, "The Treatment and Cure of a Case of Mental and Moral Deficiency," Psychological Clinic, vol. ii, 1908, p. 153; and Smith, " Sixty-two Days* Training of a Backward Boy," Psychologi- cal Clinic, vol. ii, pp. 5, 29 and 134. DEFECTIVE VISION 85 The next line of letters is large enough so that it may normally be read at 100 feet, the next at 70 feet, and so on down. The line next to the bottom is usually one that should be read at 20 feet, and the bottom line one that can be read only at 12 feet. The distance at which each line ought to be read is printed beside it on the test card. To test a child's vision, this card is hung on the wall in a good light a distance of 20 feet in front of the child. The child reads the letters as the teacher points them out, beginning at the top line and going down to a line where he misses more than one letter. The result of the test is recorded as a fraction, of which the numerator is the distance at which the child is standing from the chart and the denominator the distance at which the smallest line he can read should be legible, as indicated by the distance printed beside it. Thus, if a child, standing at the standard distance of 20 feet from the chart, can read all the letters of the 20-feet line, or all but one of them, with his right eye, but can read only those of the 40-feet line with his left, the vision of his right eye is l^, or normal, while that of his left eye is |J, or one-half. Each eye must be tested separately, and the eye not being tested kept open, but covered by a card held close in front of it. Visual acuity oi }i to }^ is not regarded as particu- larly bad. The percentage of children having various degrees of defective vision varies greatly from class to class. On the average, results something like the follow- ing may be expected : A visual acuity in one or both eyes of ys or worse in 6 or 8 per cent. ; of >^ or worse, in 10 to 15 per cent. ; of ^ or worse, in 15 to 35 per cent. The test for visual acuity detects all those who have defective vision at the distance of twenty feet; but it 86 PHYSICAL DEFECTS misses many whose vision is very poor at the ordinary reading distance. It cannot be counted upon to detect those who are suffering from one of the commonest as well as most serious visual defects, namely, far-sighted- ness. The reason is not hard to understand. The far- sighted person sees as well at a distance as the possessor of nomial vision; he is merely unable to see clearly objects which are close at hand. At a distance as great as twenty feet, the far-sighted person may see as easily as anybcxly else, and if he cannot see as easily, he can yet manage to see as well, simply by straining his eyes a little. He may even succeed in reading at the ordinary distance — but only by straining his eyes to a very excessive and injur- ious degree. Such a person suffers greatly in using his eyes for reading, for they must work constantly under an enormous strain. Clearly, far-sightedness is more serious than near-sightedness. The near-sighted pupil cannot read well at a distance of twenty feet but he may not be bothered at all in near w^ork; whereas the far- sighted pupil, who passes the reading test at tw^enty feet, with little or no eye-strain, may yet be utterly unable to read print close at hand. When we consider that in. school children far-sightedness is several times as common as near-sightedness, it is obvious that the Snellen chart test has to be supplemented by one for far-sightedness. The simplest way of especially testing far-sightedness is to have the child read through a weak convex lens or magnifying glass, or through a pair of spectacles with two diopter lenses,^ such as may be had from any spectacle dealer. If these convex lenses do not make his vision worse, it is likely that the child is far-sighted. ' Sec Dnimmond, "An Tntroduction to School Hygiene," p. 135. A two diopter lens is one of low power, whose focal length is one- half meter. DEFECTIVE VISION 87 Even the lens test may fail, if, from habit, the far- sighted child refuses to relax his eyes. It is necessary, therefore, to have the child examined by a specialist when- ever there is any reason to suspect that his vision is defec- tive, even though he passes the tests. In this connection, the teacher should be alert to notice the symptoms of eye- strain in her pupils. These symptoms consist in an aching or tiring of the eyes with prolonged reading, smarting or itching, and a blurring or running together of the letters. Frequent headaches are in themselves a sufficient symptom. According to Cornell,^ " the only considerable cause of habitual headache in children is eye-strain." It is not sufficient that children suffering from defec- tive vision receive proper examination and treatment by an oculist. When glasses are prescribed, the teacher must see to it that they are worn. The child should be impressed by the notion of their value. Spectacles are a great invention, due, it is said, to Sal vino d'Armati of Florence, who died in 13 17. At one time, the cost of a pair of glasses, was equal to 50 to 100 dollars, and even if they cost that to-day they would be cheap at the price — as one may perceive by considering the earning ability of those men who, but for their glasses, would hardly be self-supporting. Besides making sure that children wear their glasses, the teacher should guard against glasses that are not properly fitted. She can do this by watching care- fully for symptoms of eye-strain. Vision may change. There is a tendency for far-sightedness to diminish and for near-sightedness to increase as children grow older; so that it is necessary from time to time to have the eyes examined, even though they may be already fitted with " " Health and Medical Inspection of School Children," 1912, p. 221. 88 PHYSICAL DEFECTS glasses. Various eye defects, frequently associated with defective vision, should not go unobserved. Styes, squints and swollen or reddened eyelids are readily noted ; but in addition the teacher should watch for cliildren who have a tense facial expression and a tendency to screw up their eyes when looking at the blackboard, who hold their books close to their eyes, or stoop down close to their work, or who show excessive blinking and over-sensitivity to light. Defective Hearing. — Almost as important as defects of vision are those of hearing. They affect in the neigh- borhood of five per cent, of all children, and are often attended with serious results. Besides his direct loss, a child with defective hearing may suffer a number of indirect bad consequences. Speech is likely to be peculiar, as the mutism that accompanies total deafness indicates. The continual leaning forward to hear may cause stoop shoulders and flat chest, and these, in turn, increase a liabil- ity to tuberculosis. Inattention may become pronounced, merely because of the great effort required to hear, and may lead to an undeserved reputation for dullness. Par- tial isolation from normal play and social intercourse with other children leads to the acquisition of a peculiar temperament, shown in a tendency towards self -analysis and suspiciousness of others. Numerous statistics prove that school work is seriously handicapped by deafness. While children with defective hearing are by no means always retarded, a much larger percentage of such chil- dren is found among those who are retarded than among those who are advanced. To some extent this may be accounted for by the association of deafness with other defects, such as adenoids and even with dullness itself. It is for the most part, however, due directly to the obvious handicap of defective hearing. DEFECTIVE HEARING 89 Hearing ability may be l^est examined by what is known as the whisper test. As conducted by Kirkpatrick, a number of children may be tested at the same time. He describes his procedure substantially as follows : ^ The children take seats in three rows, tliree or four or even five children in a row. They are supplied with pencil and paper and asked to keep their eyes to the front. The teacher stands to the right, opposite the middle pupil, and pronounces in a low, distinct whisper a series of numbers which they are asked to write after her, one at a time, as in a dictation exercise. After four or five numbers have been given, the children change seats; those in the row nearest the teacher take the seats of those in the farthest row ; those in the farthest row move to the mid- dle; and those in the middle move to the nearest row. Then the teacher whispers another series of numbers. The moving is repeated, and the teacher whispers a third series. This completes the test for the right ear — all the children having been tested at three distances, near, far and medium. The left ear is tested in a similar way, the teacher standing to the children's left. She collects the papers and grades them by taking the total number of digits written correctly. The totals for the right ear and left ear are averaged for the class. The hearing ability of each ear for each child is then recorded in the form of a fraction, the denominator of which is the aver- age for the class and the numerator the number of digits correctly written by the individual child. The record shows the acuteness of hearing of each child in comparison with that of his classmates. With this record before her it should not be hard for the teacher to tell which children require the attention of an ear specialist. ^Psychological CUnic, 1909, pp. 96, 97. 90 PHYSICAL DEFECTS Defects of hearing must, imperatively, be recognized early in life. Long-standing cases are likely to be rather obstinate. Small children almost never complain on their own initiative of inability to hear, and older children may frequently conceal their infirmity on account of timidity. Such symptoms as mouth-breathing and earache, apparent stupidity, or even slowness or hesitation in executing commands, should be regarded as sufficient to necessitate an examination by the physician. A discliarging ear should be given immediate attention. If chronic, it indi- cates an inflammation of the middle ear, within the skull, which may result in very serious consequences. Non-sensory Defects. — Among the most frequent of the non-sensory physical defects met with in school chil- dren are the following: Defective glands; enlarged ton- sils; adenoids, consisting of little swellings which grow in the passageway connecting the nose with the throat and block it up; nasal catarrh and nasal obstructions of one sort or another; stuttering and lisping; malnutrition; defective teeth, particularly frequent in the younger chil- dren; nervous disorders; diseases of the heart, lungs, and skin; and diseases or deformities of the skeleton. Many of these troubles can be recognized only by the physician. Note, however, that a number of them are located in the neighlx^rhood of the mouth and throat. For this reason, a teacher should be familiar with the normal appearance of this region. " Look into the children's mouths " is good pedagogy aiid sound psychology. It stands for the principle of careful individual observation of children, a principle which one must follow if he is to guide cliildren successfully in their mental development. The removal of adenoids and of tonsils is not infre- quently accompanied by a marked improvement in general^ STIGMATA OF DEGENERACY 91 health and a decrease in susceptibility to colds and sore throat. Marked improvement in mental ability may also result. A num.l)er of studies indicate that children who are retarded in school may do better work after the removal of these sources of infection. In fact, the majority of all cases of sudden improvement in mentality are those in which adenoids or tonsils have been removed. Removal of adenoids may lead to a much improved facial expression, by permitting- the child to breathe through his nose instead of a wide-open mouth. It may also result in better attention by removing the distraction caused by mouth-breathing. When the adenoids have been respon- sible, as they sometimes are, for catarrh in the ear, their removal may result in improvement in hearing. However, in numerous cases, no mental improvement at all follows. In an investigation of the effects brought about by removal of adenoids in a group of children retarded in their school work, Cornell found that according to the opinion of the teachers a considerable number were not benefited men- tally, and that the entire group received 52 failures to 32 promotions during the year after the operation.^ Stigmata of Degeneracy. — Before leaving the subject of physical defects, I must mention the so-called " stig- mata of degeneracy." These have been widely discussed and have attracted a great deal of notoriety as signs of criminality, insanity, and feeble-mindedness. Certain defects have been given this name on the theory that they originate in defects in the germ cells from which the individual develops. Needless to say, it is often extremely difficult to decide whether a physical defect owes its origin to defective germ plasm or not; and it is conse- *" Health and Medical Inspection of School Children," 1912, pp. 276-278. 9'^ PHYSICAL DEFECTS i[iiont!y not siirprisiiii; that there exists i;Teat cUsai^ree- inent between anthiM'ities as to what slu)uKl be ennnierated as stii;niata oi tlei;eneraey. Ahnc>st every tleviation from the normal has been inehuled by some writer or other; and lliere is no hst that diH\s not inchule defects that may not be due to other factors than defective i^erm phism. riie followini;^ hst is perhaps fairly representative: 1. I'ndersized cm* misshaped liead. 2. Oefeetive heii;ht and weii;ht. ^^ Misshaped ears: IVenharities of form and size of the external ear and its varions parts. 4. IX^formities connected with the eyes : Crossed eyes; nystai;nms. a rapid movement of the eyes from side to side, especially noticeable when the child tries to fixate an object lyini;" in a new direction; small, c^blicpie (^jHMiini;- between the eyelids, etc. 5. Nose, lips and palate: Tecnliarities oi size and l\^rm; slavering;-: protnulini^- jaw; small and recedini;* jaw ; adenoids. (\ Teeth : Irrci^iilarities oi position, nnmber. form and si.-e; delay in a[>pearance cU" either temporarv or jvrma- nent teeth. 7. Oefective circnlation and respiration. 8. Oe feels oi the alimentary or digestive svstcni. o. Hair: Its absence from customary places or its presence in nnnsnal places. 10. Oefective facial expression. Now any of the above defects may appear in persons who are otherwise perfectly normal. Nevertheless, they are far more numerous in persiMis of a degenerate type, especially the feeble-minded. In an examination of two hundred morons. Lapage found stig^nata in all but nine- STIGMATA OF DEGENERACY 93 teen, and, not uncommonly, three or more stigmata in the same individual. They are more numerous in imbeciles and idiots, than in morons. Clouston found deformed palates in nineteen per cent, of the ordinary population, but in sixty-one per cent, of idiots. It is now fairly well established that there exists a rough correlation l^tween the number, severity and extensiveness of stigmata and innate defectiveness of the central nervous system.*^ One or even two of these stigmata may be of no particular importance; but if they are more numerous, they are significant. By themselves, stigmata of degeneracy should never be taken as evidence of dullness or feeble-mindedness. They are quite too unreliable. They have significance only in those cases in which, as the result of mental tests or other observations, mental subnormality is already known to exist. In these cases, stigmata have some signifi- cance as regards the cause of the mental subnormality. The stigmata, while never conclusive, are a sign of defec- tiveness in the germ cells from which the child has devel- oped. When, then, the child is already known to be retarded, the presence of stigmata may be regarded as evidence that his retardation is inborn, that it is dullness rather than mere backwardness, that it is not due to tem- porary causes which may be either easily remedied or out- grown, but that on the contrary it is an ingrained, permanent feature of his constitution. All in all, soundness of body is correlated with sound- ness of mind. With regard to any other part of the body than the central nervous system, however, the correlation is so slight that all our elaborate measurements scarcely 'Bosbauer, Miklas unci Schiner, " Handbuch der Schwachsin- nigenfiirsorge," 1909, p. 30. 94 PHYSICAL DEFECTS do more than establish its existence. In the case of the central nervous system, there is abundant evidence of a very high correlation, particularly with certain features of the cerebral cortex. Here, owing to the diflficulty of access, we are still greatly in need of more precise data. Enough is known, however, so that we may be confident that brightness is much more highly correlated with the number and development of the cortical cells than with any other bodily features. The correlation is at least so high, that, in the absence of any information concerning a child except that he is superior or dull, we may assume as the most probable cause of his mental condition the state of his cerebral cortex. Medical Inspection and Its Relation to the Teacher. — • In concluding this chapter on physical defects, I shall add a few comments on medical inspection and its relation to the teacher. To some people, who greatly exaggerated the connection between physical defects and mentality, the results of medical inspection have been a disappointment. They were disappointed to observe that children still con- tinued as usual to fail in school work in large numbers. To those who better understood the true relationship between mind and body, medical inspection appeared not only successful but indispensable. In the United States, medical inspection has had to fight against considerable prejudice. Its desirability, however, is beyond debate ; the only problem, now, is how to make it more efficient. In the solution of this problem, a great deal depends upon the cooperation of the teacher. Medical inspection is now nearly a century old. It originated in France, where, in 1837, a royal ordinance made it the special duty of the female supervisors of kindergartens to watch over the health of the children. MEDICAL INSPECTION 95 It is now well-nigh universal. Medical inspection has been adopted by all the nations of Europe as well as in many other parts of the world. The Argentine Republic is said to have one of the most thorough systems of medi- cal inspection in existence ; and Japan has a system which embraces the entire empire, including the most remote rural districts.^ In the United States, since the inception of the movement in Boston in 1894, its expansion has been very rapid. Medical inspection has a twofold aim : First, the detec- tion of communicable diseases, which has as its main object the protection of the community; and, second, physical examination, which aims to discover defects and dis- eases, and to note the general physical condition of chil- dren. In both these aims the cooperation of the teacher is invaluable. The teacher should be familiar with the symptoms of infectious diseases,^ and constantly on the watch for them. In the physical examination, also, the teacher may cooperate by testing vision and hearing and by looking out for other physical defects. In some states, teachers are required by law to make tests of the vision and hearing of their pupils. Even in cities which have an adequate system of medical inspection, it is desirable, even though not required, that the teachers should be able to make such tests. The object, of course, is not to arrive at a diagnosis of causes, but merely to determine whether vision or hearing is defective, so that a thorough, examina- tion and proper treatment may be given by a specialist and so that the teacher herself may arrange for proper seating and methods of instruction. * See Gulick and Ayres, " Medical Inspection of Schools," 1908, pp. 18-26. • A convenient description of these is given by Lapage, '* Feeble- Mindedness in Children of School Age," 191 1, pp. 16&-178. 96 PHYSICAL DEFECTS The greatest of all the teacher's responsibilities, how- ever, in connection with the physical welfare of her pupils, is in the follow-up work that is necessary if medical inspec- tion is to be made successful. Parental indifference and neglect is, at present, the greatest obstacle to the success of medical inspection. In a great many cases it is very diflicult, if not impossible, to persuade parents to act upon the notification received from the medical examiner. The medical examiner himself can not remedy the defects he finds. His duty ends when he has notified the child's parents of the existence of defects; he is not permitted to correct them. However unsatisfactory this state of affairs may be, it will probably continue for a long time to come. In the meantime, follow-up work is clearly necessary, unless a large part of the medical inspector's labor is to be wasted. Sometimes it is made the special duty of the school mu'se to see to it that proper measures are taken for the correction or treatment of physical defects ; but the respon- sibility of the teacher is never entirely removed. If the school is fortunate enough to possess an efficient school nurse, it may never be necessary for the teacher to deal directly with the child's parents. All that may be required of her is strict insistence against neglect. In less fortunate circumstances, the teacher must take more active measures. The teacher, by virtue of her position of direct authority over the education of children entrusted to her care, must hold herself responsible for the proper treatment of every remedial physical defect present in her pupils. The correc- tion of physical defects is as nuich an educational measure as the correction of illiteracy. The teacher nuist accept the responsibility for both, whether or not the administra- tive authorities ask her to do so. CHAPTER VI ANATOMICAL AGE The Various Child Ages. — According to psychology, every child has a number of different ages, each of which represents an appraisement of some one of the factors comprising his complex existence. The four most import- ant are the chronological, mental, pedagogical and physiological, or anatomical, ages. Each of these ages has different implications. The chronological tells only how long the child has lived. The mental age states his amount of intelligence. The peda- gogical age gives his school grade. It is merely a sub- division of what may be termed his acquisitional age, the age which tells how much he has acquired in the way of information and serviceable habits. His physiological age records the extent to which his bodily functions have developed. It is distinguishable from anatomical age, which expresses the stage of growth of the bodily struc- tures, but physiological and anatomical age are so closely related that for educational purposes they may be united under the head of anatomical age. Each of these ages is to a large extent independent of the others. We have already seen that a child's mental age may be far beyond or behind his chronological age. Like- wise, pedagogical age and anatomical age may differ widely from chronological age. Pedagogical age, which refers to a child's school grade, might be supposed insepa- rable from mental age, but, unfortunately, it does not always prove to be so. The grade a child attains in school 7 97 98 ANATOMICAL AGE depends upon his age at entering, upon the flexibiUty of the grading system to which he is subjected and other factors, as well as upon his intelligence. Pedagogical age and mental age not only differ from each other, but are both quite distinct from anatomical age. This dis- tinction is most striking in idiots and imbeciles, who may be fairly well developed physically and yet possess prac- tically nothing of intelligence or information. While the various ages are distinct and to a certain extent independent, their true significance is clear only when they are considered in relation to each other. To know a child's mental age, for example, is of compara- tively little value, unless his chronological age is also known. If, however, we know the relation of the former to the latter, we can form some idea of the child's bright- ness, to some extent can predict his future, and begin to plan his education with some measure of wisdom. Thus considered in relation to the other ages of the child, both the anatomical and pedagogical age contribute immensely to the understanding of the child's nature — his needs and his potentialities. Anatomical Age. — The measurement of any of these ages, except the chronological, requires that norms or standards be first established, because the measurement is made by applying a scale showing the attainments of normal children at each of the chronological ages. Thus, as heretofore stated, a child has the mental age ten if he manifests the amount of intelligence of an average ten- year-old child ; so that mental age may be defined as that degree of intelligence shown by an average child of the corresponding chronological age. Anatomical age is defined and measured in a similar manner. It is an age which represents the degree of physical development ANATOMICAL AGE 99 attained by the average child of the corresponding chrono- logical age. If a child has not attained the anatomical development of normal children of his own chronological age, he is anatomically retarded; if he has attained a stage reached on the average only by children older than himself, he is anatomically advanced. By the stage of a child's physical development is meant neither his health, nor his strength, nor even his size, but simply the point at v^hich he has arrived in that series of changes by which the body of a child is trans- formed into that of an adult. It is well known that the development of the body is marked by numerous definite changes in the structure of its parts, and that in all per- sons a certain condition is finally reached which marks the end of these changes. For example, everyone acquires a certain number of teeth and no more. We know that a child who has only one or two of his permanent teeth has a larger number of stages still to traverse than has the child who has already four or five of his permanent teeth, and a much smaller number of stages yet before him than has the child who has not acquired any permanent teeth. When all the teeth have appeared, anatomical development with respect to teeth is complete, no matter whether the teeth are good or bad, and no matter whether the child's body is large or small, strong or weak. It is clear that stages of this sort are quite different from such things as strength or height. When a boy has two per- manent teeth, we know how many more he will eventually possess ; whereas when he has reached four feet in height, we do not know how much more he is to grow. We know the height of the average man, but we do not know the height any particular boy will attain when he becomes a man. Perhaps we can estimate what his final height will loo ANATOMICAL AGE be, but his actual height does not directly represent a definite stage in a known series of developmental changes, leading to a known final stage, as does the number of teeth. Both mental and anatomical ages measure something in the child by comparison with the attainments of normal children ; but they differ in a very important respect, apart from the fact that one measures something mental and the other something physical. This difference has often been overlooked with the result that great confusion has existed concerning the use to be made of the knowledge of a child's anatomical age. The word age has a quite different meaning in the two cases. In mental age, the term indi- cates an amount, in anatomical age, a proportion. Mental age tells us how much intelligence the child has ; it does not tell us what proportion of his final intelligence he already possesses. Anatomical age, on the other hand, does not indicate the amount of physical development, but merely the proportion of the final development reached at a given period. Of course it does not give this proportion directly in the form of a fraction; but it does give directly the stage reached in a known series of vStages. We know what stages have gone before and what remain to be traversed. The Indices of Anatomical Age. — To the question, then, what is the best way to determine a child's anatomical age, different answers have been given. In the main, reliance has been placed on one or the other of three indices. Dr. Bean emphasizes the value of the time when the permanent teeth appear as a measure of anatomical age.^ Dr. Crampton, who, while assistant director of *"The Eruption of the Teeth as a Physiological Standard lor Testing Development" Pedagogical Seminary, vol. xxi, 1914, pp. 596-614. THE ERUPTION OF TEETH loi physical training in the pubhc schools of New York City, was one of the first to call attention to the impor- tance of a knowledge of anatomical age, uses the onset of puberty as a sign.^ Dr. Rotch and others have argued that the most reliable index of anatomical age is the degree of development of the skeleton.^ Dr. Rotch and Dr. Pryor ^ have established the fact that the degree of skeletal development may be used with a high degree of accuracy at all ages from birth to maturity, as an index of anatomical age. All three of these indices show sub- stantial interagreement. The Eruption of Teeth. — ^The most convenient means of determining anatomical age is afforded by the eruption of the teeth. The teeth can be counted and identified by almost anyone, after a little experience, and they are, obviously, either definitely absent or present; conse- quently, their use as measures of anatomical age does not call for much interpretative ability! Some students of anatomical age regard dentition as the best single indi- cator, particularly at the earlier school ages.^ From the age of entering school until the age of twelve, a child's anatomical age can be fixed within quite narrow limits solely by inspection of his teeth. The first permanent teeth are the lower molars. These normally ' " Anatomical or Physiological Age Versus Chronological Age," Pedagogical Seminary, vol. xv, 1908, pp. 230-237 ; and " Physiological Age," American Physical Education Review, vol. xiii, 1908, pp. 141- 154, 214-227, 268-283 and 345-358. ^ " Rontgen-ray Methods Applied to the Grading of Early Life. American Physical Education Review, vol. xv, 1910, pp. 396-420. * Bulletins of the State College of Kentucky : 1905, " Develop- ment of the Bones of the Hand," pp. 30 : 1906, " Ossification of the Epiphyses of the Hand," pp. 35 ; 1908. " The Chronology and Order of Ossification of the Bones of the Human Carpus, pp. 24. *See Beik, "Physiological Age and School Entrance." Peda- gogical Seminary, vol. xx, 1913, p. 302. I02 ANATOMICAL AGE apprar at the ai;c of six. They appear just behind the rearmost temporary teeth, and thus, eountiug from the middle hue of the front of tlie mouth, occupy the sixth place. Hieir position in the mouth as well as that of the other teeth is shown in the accompanying- hgiu-e, No. 6. Fui. 6.— The ixTinaiiont tooth (after Tostut and Jacob, "Traits d'anatoinio txMH\j;rapluquo," vol. i, 190*), p. 206). 1,1, central incisors; 2, 2, lateral incisors; 3, 3, canines; 4, 4, iirst premolars; 5, 5, second pre- molars; 6, 6, first molars; 7, 7, second molars; 8, 8, third molars (wisdom 1 colli). About six months after the fu-st molars come the two lower central incisors. The remaining teeth appear in reg-ular order from the front Ixickwards, except that the first premolars may erupt Ix^fore the lower canines, and both the first and second premolars before tlie upper canines. THE ERUPTION OF TEETH 103 riic normal aj^c of eruption for any tooth varies. I'art of this variation is (hie to race and sex (hfferences. I lie teeth of French children mature more ra|)i(lly, and those of German children less rapidly than those of y\m,erican children." (Jirls acciuire thcii^ teeth earlier than do boys. But even in individuals of the same race and sex, there is a considerable variation in the a^e of eruption of the teeth, and on this account, it is not alto- j^cther easy to construct a normal scale. I lowever, sufli- ciently extensive investij^^ations have been made that it is ])()ssible to state within a month or so at what age one-half of all children jKissess a j^^^iven tooth. 'J'his aj^e is rela- tively the normal age. If, then, a child's teeth erupt at the chronological ages indicated in the following table as Taiili'; Sii()\vin<; iiikAcik of ICkui'tion ok tmic Pickmanicnt 'ri';i':Tn * A SCALE FOR MEASUKINCJ ANATOMICAL AGE Name of tooth Lower first molar Upper llrsl molar Lower c:enl,r.'il incisors. Upper eeiiUal iiieisors. Lower lateral incisors.. UjjpcM- laUM-al iticisors. . Upp(!r first premolai's. . Lower first pn^molars. . Lowi;r canines Upper second i)remoIars lAtwv.r sec^ond jiremolars Up|)er canines L()W(>r se("on(l molars. . lJpp(>r second molars. . Third molars Normul ajco (premint in SO \n'.r c.(Mit.) 6yrs. J710S. 6yrs. 3 mos. 6yrs. () mos. 7 yrs. 6 mos. 7 yrs. mos. H yrs. 6 mos. 10 yrs. o mos. 10 yrs. C) mos. 10 yrs. mos. 1 1 yrs. o n)os. 1 1 yrs. 6 mos. 1 1 yrs. 9 mos. 1 1 yrs. 9 mos. 12 yrs. 6 mos. 17th to 24th year PrcHont in 25 jxrr rent, of cliilflren 5 y»"'^. 5 y»'-^. (i yrs. 7 yrs. 7 yrs. H yrs. « yrs. 9 ys. 9 yrs. 9 yrs. 10 yrs. 10 yrs. 10 yrs. 1 1 yrs. 6 mos. 9 mos. o mos. omos. omos. omos. 9 mos. Omos. 9 mos. 9 mos. 3 mos. 9 mos. 9 mos. 6 mos. PreBont in 7S t)«ir c«mt. or children 6 yi'S. 7 yrs, 7 ys. 8 yrs. 8 yrs. 9 yis. 10 yrs. 1 1 yrs. 1 2 y rs. 1 2 y rs. 1 2 yrs, 1 2 yrs. 14 yrs. 14 yrs. 6 mos. o mos. mos. 3 mos. mos. 3 mos. f9 mos. 9 mos. 3 mos. omos. 6 mos. 9 mos. o mos. 3 mos. * Thi<« tuhlf! is h(isc ('hildrcn, Arch under Twelve," I'mrerdinRS nf the Royal Sorirty of Mrdirinc, vol. v. 1012. Tt agrees atibstantially with the data of Tivan on dentition in American school childrrn. ' Bean, op. cit., pp. 603-605. 104 ANATOMICAL AGE normal, he is normal in anatomical age; if his teeth erupt at a later age, he is anatomically retarded, and if at an earlier age, anatomically advanced. The table does not give different norms for the different sexes, for it is desirable to have one standard for both sexes, just as in the scale for measuring intelligence. Then, by applying the same standard of anatomical development to each sex, the difference l^etween the sexes can easily be measured. The Ossification of the Wrist Bones. — The stage of skeletal development is best judged by the bones of the wrist. The wrist contains eight small bones, the carpal bones, the development of each of which, from cartilage into bone, occurs at a different age. The change from cartilage to bone, known as ossification, is readily fol- lowed by means of Rontgen ray photographs. The first ossification, that of the os magnum, occurs towards the end of the first year of life, and the last, that of the pisi- form bone, occurs normally during the eleventh year. The ossification of the other wrist bones is distributed over the inteniicdiate years. In addition to the stages formed by the development of the wrist bones, there are others, marked by certain changes in the wrist end of the bones of the forearm, the tdna and the radius. The ossification of a bone such as the ulna or the radius begins in its middle portion, or shaft. The shaft grows in length by an extended ossification of the cartilage towards both ends. While the shaft is thus growing towards the ends of the bone, ossification begins at new starting points in the ends and progresses towards the centre. Thus at one stage in the formation of a bone like those of the forearm, the shaft is separated from the ends of the bone by a zone of cartilage. The shaft and the ends, the latter known as epiphyses, continue THE OSSIFICATION OF THE WRIST BONES 105 to grow towards each other until there is a complete bony union. The different stages of development of the ends, or epiphyses of the ulna and radius form a valuable supple- ment to the scale of anatomical age afforded by the devel- opment of the wrist bones. The development of the end of the ulna is particularly valuable, because complete bony union with the shaft is not established until long after the last of the wrist bones has ossified. Additional information concerning anatomical age may sometimes be gained by studying the degree of development shown by the ends of the bones in the palm of the hand, and in the fingers and thumb. All the bones of the hand and wrist, as well as the ends of the ulna and radius, are easily included in one radiograph. Consequently, by a single, objective impression, an accurate record of a child's anatomical age may be obtained. The record may be taken as often as desired, and at any age from birth to maturity. Of all the indicators of anatomical age, the stages of development shown by the skeleton and the teeth are the most reliable. The development of the skeleton, in par- ticular, is very little affected by adverse circumstances. This has been shown by several studies on the effect upon the growth of the various bodily organs, brought about by underfeeding of animals. These studies estab- lish the fact that the bones form the most stable part of the body. Dr. Jackson, studying the growth of young white rats, found that the skeleton continues to grow even when, by means of underfeeding, the weight of the body as a whole is kept constant. " The increase in the skeleton during constant body weight," he writes, *' appears to involve the ligaments as well as the cartilages io6 ANATOMICAL AGE and bones. ' The skeletal growth tends to proceed along the lines of normal development, as indicated by the decrease in water-content and by formation and union of various epiphyses." '^ Like results have been obtained by investigations of the calf, the dog and the cat. Like- wise it has been found that malnutrition in children retards growth in length (consequently, skeletal growth) less than growth in Ixxly weight, so that the skeleton may continue to grow even while the weight of the body re- mains practically at a standstill. rh()togra])lis of the wrist bones have been compared with those of other parts of the skeleton, such as the elbow, shoulder, knee, and ankle. The result has been general agreement that the development of the wrist bones affords both the most reliable and the most prac- tical single index of general skeletal development. " It has been determined," writes Rotch, '' that the appearance of the carpal bones and the epiphyses of the radius and ulna represent the stage of development of all the other epiphyses throughout the skeleton, so that the bones of the wrist may be relied upon to judge of epiphyseal development without having to take Rontgen pictures of the other epiphyses." ^ Variation in the Anatomical Age of Children. — 1 have already pointed out that children of the same chrono- logical age vary enormously in intelligence, or mental age. 1 have indicated that in an average group of one hundred ten-year-old school children, we may expect to fmd chil- dren of all mental ages from seven to thirteen. Simi- ' " Changes in the Relative Weights of the Various Parts, Sys- tems and Origans of Younp: Albino Rats TTeld at Constant Rody Weight hy Underfeeding- for Varions Periods." Journal of Experi- mental Zoology, vol. xix, 1915, p. 153. " O/). cit., p. 397. VARIATION IN ANATOMICAL AGE 107 larly, as is proved by data in the following chapter, in any large school system, ten-year-old children may be found in all grades from the first to the sixth, and this in spite of a certain tendency of the schools to force all children along at a uniform rate. Thus, both in mental age and school grade, ten-year-old children are found distributed over a range equal to that covered by normal children differing by five or six years in chronological age. This variation in the mental ability of ten-year-old children, large as it is, is almost equalled by that in ana- tomical age. Measured by whatever index, the anatomical ages of ten-year-old children distribute themselves over a distance which it takes the average child five or six years to traverse. Such great deviations from normal make it highly important that anatomical age be taken into con- sideration in estimating the child's potentialities. With- out a knowledge of a child's anatomical age, we cannot properly appraise his mental ability. I have stated that mental age has significance only when compared with chronological age. It acquires its true significance, how- ever, only when compared with anatomical age. It is con- sequently well to realize how greatly children of the same chronological age vary in anatomical age. I shall give illustrations of the extent of this variation in the case of all three of the commonly used indices — dentition, pubes- cence, and ossification of the wrist bones. In the table showing the age of eruption of the various permanent teeth, it is indicated that the chronological age at which a given tooth will erupt in twenty-five per cent, of children is considerably lower than the age which must be reached before it will be present in seventy-five per cent, of them. The difference between the two ages io8 ANATOMICAL AGE is about one year for the first molars and the incisors, but increases to two years or over for the remaining teeth; so that we may say that with fifty per cent, of chil- dren, each tooth makes its appearance during an age inter- val of one or two years. The total range of ages, however, at which a tooth may appear is much greater than this. The upper central incisors, for example, appear in some children as early as the age of live years and three months. and in others as late as nine years and nine months, thus covering a range of four years and six months. The upper lateral incisors cover a range of over five years, and the upper premolars and canines a range of over six years. The older the normal age of appearance of a tooth, the greater will be the range of years at which it may appear. This is simply one aspect of the general law that differ- ences between individuals measured in terms of years of development tend to increase as the individuals grow older. Just as a slight difference in mental age at the earlier ages is the equivalent of a large one at the later ages, so does a slight difference in anatomical age at the earlier ages predict a large one at later ages. In regard to pubescence, Crampton has found that some boys cross this landmark of physical development as early as the age of twelve and a half, while others do not do so before the age of seventeen and a half to eighteen. There is a variation, then, in the male sex alone, of five years. Crampton distingtiishes three stages, which he calls the pre-pubescent, the pubescent and the post- pubescent. The percentage of boys which he found in each of these three stages is shown in the following table, covering the ages of twelve and a half to eighteen.^ ■ • Pedagogical Seminary, vol. xv, 1908, p. 232. VARIATION IN ANATOMICAL AGE 109 Age of Pubescence in Boys Age in years Pre-pubescent Pubescent Post-pubescent (per cent.) (per cent.) (per cent.) I2.5-13.O 69 25 6 13-0-13.5 55 26 18 I3.5-14.O 41 28 31 I4.O-14.5 26 34 40 I4.5-15.O 16 24 60 15.0-15-5 9 20 70 I5.5-16.O 5 10 85 16.O-16.5 2 4 93 16.5-17.O I 4 95 17.O-17.5 2 98 17.5-18.O 100 To give an idea of the variation in anatomical age as measured by the development of the carpal bones, I cannot do better than to describe the results of an inten- sive study of one hundred ten-year-old school children undertaken at my suggestion by Mr. Severson, principal of a grade school in the city of Minneapolis. The Rontgen ray photographs of these ten-year-old children differed so greatly that we found it possible to distinguish ten different stages of anatomical age. The lowest of these classes corresponds to that shown by an average girl of about eight years of age (or boy of seven) and the high- est to that of an average girl of about fourteen years (or boy of twelve). The range in anatomical age of our ten-year-old group then, including both boys and girls, is about six years. The accompanying photographs show what radical variations exist in the anatomical development of these children, all ten years old chronologically. The highest class, represented by radiograph No. i, shows a good development of the pisiform bone, the last of the eight carpals to ossify. It shows, too, a very good develop- no ANATOMICAL AGE ment of the ends, or epiphyses, of the radius (the large forearm bone) and of the ulna (the small forearm bone). Ossification of the epiphyses has progressed so far that there begins to be a junction of the epiphyses with the shafts. All the carpal bones of the wrist are well devel- oped, so that there is little space between them. It may be noted, too, that this advanced stage of anatomical development does not necessitate a large hand. The hand shown in radiograph No. i is small, but better developed than the larger, Nos. 2 and 3. Radiograph No. 2 represents the sixth (counting up from the lowest) of the ten classes which we were able to distinguish in ten-year-old children. It is the lowest class in which the pisiform is plainly evident. The pisi- form shows simply as a dark spot lying below and to one comer of the cuneiform. The epiphyses, particularly that of the ulna, are very poorly developed compared with their condition in class ten (radiograph No. i). Radiograph No. 3 represents one of the least devel- oped hands in the entire group of one hundred. There is absolutely no trace of a pisiform bone, and, what is much more striking, scarcely more than a speck to repre- sent the epiphysis of the ulna. According to Pryor, the ulnar epiphysis appears typically at the age of six and a quarter in girls, and seven and a quarter in boys. This hand does not correspond to an age much above these. It will be noted, too, that some of the other bones are very poorly developed, so that there are large spaces left between them. Sex Differences. — It is well known that girls reach the age of puberty on the average about two and a half years earlier than boys. At this period the anatomical age SEX DIFFERENCES Hi of the girl is clearly well beyond that of the boy of the same chronological age. It is not so commonly realized that this difference between the sexes in anatomical age is well marked by the end of the first year of life, and that it is present in ever increasing degree from the first year up to and beyond the age of puberty. That, however, is the conclusion to which leads either of the measures, eruption of teeth or the ossification of carpals. A comparison of the sexes as regards anatomical age has been worked out in some detail by Pr>^or on the basis of carpal ossification. In round figures he finds the fol- lowing differences: From the age of one to the age of two, the difference in anatomical age is about one-half year. Anatomically, the girl of one and a half years is as old as the boy of two. This difference gradually increases. At the age of four the girl is anatomically as old as the Boy of five. By the age of seven and a half the girl is as old anatomically as the boy of nine, and by the age of ten and a quarter she is as old as the boy of twelve and three-quarters. This latter difference agrees with that displayed at puberty, with respect to which we may say that the girl of twelve and a half is as old as the boy of fifteen. These differences may be summed up in a little table, showing at what ages the two sexes are equal in ana- tomical age. The table shows that sex differences, like individual differences, increase with age. A similar table based on dentition would corroborate this fact. American girls at the age of eleven possess on the average 21.3 per- manent teeth; the boys can boast only 17.3.^^ ^° Bean, op. cit, p. 599- 112 ANATOMICAL AGE Sex Differences ix Anatomical Ace as Measured by Ossification of the Wrist Bones Girl's i»jo Anatonnortlly equivalent boys age Difference 1 NT. 6 inos. 2 NTS. mos. 6 mos. 2 NTS. I1K\>. 3 NTS. (> nu^s. 3 NTS. 3 mos. 4 NTS. 3 mos. 9 mt^. 9 mos. 4 yrs. g mos. yi-s. 3 mc\<;. 7 yrs. nu\^. 8 vrs. 6 nu^s. 5 yrs. 9 mos. 7 NTS. 3 mos. 9 yrs. mos. 10 vrs. o mos. 12 mos. 12 mos. 18 mos. iS mos. 10 yi-s. 3 iiK^s. I J NTS. mas. 12 yrs. 9 mos. 15 yrs. mos. 30 mos. 30 mos. To illustrate the difference in anatomical ago between the sexes. I have chosen two Ronti^en photographs. One of these shows the carpal development of the median girl and the other of the median Ix^y, Ix^th of the same cliro- nological age group, a group distnbuted closely around ten and a half. The ditterence between these two ront- genographs, here reproduced, equals alx^ut two years of chronological age. The pisifonn lx>ne in the girl's hand (No. 4") is of considerable size, though it does not stand out clearly in the photograph Ixx'ause it is behind the cuneiform lv>ne. It will be notet.!, too, tliat the general b.Mie development is much better in the girl's wrist. In particular, tlie epiphysis of the ulna is thicker, and more closely approaches union with the shaft. In tlie boy's wrist (No. 5) there is only a vague suggestion of the presence of the pisifonn (an indistinct, dark spot at one corner of the cuneifonn") and the development of the other carpal lx">nes is mucli less adN-anced than in the girl's wrist. Anatomical Age and Mental Ability. — Children of the same chronological age, as we have seen, ditter con spicuously in both anatomical and mental age. This fact ANATOMICAL AGE AND MENTAL ABILITY 113 suggests that a considerable part of the differences in mental age may be due to differences in anatomical age. Thus the differences in mental age may not always signify differences in brightness, but may l:>e due simply to dif- ferences in rapidity of growth — to a difference in the mental and physical stage already reached rather than a difference in the final level to be attained. Anatomical age gives in physical terms alone the stage of a child's development. The question is, Does his men- tal stage correspond to his physical? Before we attempt to answer this question, it is important carefully to dis- tinguish between mental age and mental stage. Children reach different final levels of intelligence, and at different rates. We may consider mental growth evi- denced by children of different degrees of brightness as following different pathways, some of which lead to much higher final levels than others. Now whatever the final level to which a pathway leads, progress along it may be either rapid or slow. Consequently, knowledge of the path the child is taking is a different thing from knowl- edge of the proportion of its total length which he has covered. Any measure which indicates whether or not the child is following a high path or a low path is a meas- ure of brightness ; whereas any measure of the proportion of the path already covered at a given time is a measure of mental stage. Mental age reports the amount of a child's intelli- gence, but not the proportion of his final intelligence attained. It is true that from mental age we may try to determine this proportion by use of the intelligence quo- tient. But when we do this, we assume that all children of the same chronological age have completed the same proportion of their mental development. We say, for 8 114 ANATOMICAL AGE example, that whatever a child's mental age at ten, it is ten-sixteenths of what it will be at sixteen. That this assumption, true for the average, is erroneous in indi- vidual cases, is demonstrated by the great variation in developmental stage of children of the same chronological age. We must seek a more reliable indicator of develop- mental progress than mere chronological age. Now anatomical age furnishes us with a good index of the stage of physical development. Can we not stretch its use to make it serve as an indicator of the stage of mental development? The surest way to solve this problem of correspond- ence between mental stage and physical stage is to follow out both the mental and physical development of each one of a large group of cliildren from an early age to maturity. Such an investigation requires a number of years and has not yet been made. In the meantime, light is shed on the question by ascertaining whether there is any considerable correlation between mental age and ana- tomical age in children of the same chronological age. Such a correlation would indicate that mental development tends to keep pace with the anatomical, and consequently that anatomical age may be used as an indicator of mental stage. As I shall show, there exists a very decided cor- relation. It cannot be explained simply on the assump- tion that a high degree of brightness is accompanied by an advanced anatomical age ; for there exists no evidence that superior children complete tlieir anatomical develop- ment earlier than the dull ones. Its explanation lies solely in the association of rapidity of anatomical development with rapidity of mental development. I shall first cite data on the relation of mental age to ANATOMICAL AGE AND MENTAL ABILITY 115 the degree of development shown by the bones of the wrist. In the case of ten-year-old children, Mr. Severson and I were able to distinguish ten anatomical classes. To indicate the correlation of anatomical stage with mental age, we made a table showing the average mental age of each of the ten anatomical classes. The lowest anatomical class (figure No. 7, radiograph No. 3) had an average mental age of exactly nine years. The highest class (figure No. 7, radiograph No. i) had an average mental age of over ten years and eleven months. Variation in anatomical age, in children of the same chronological age, thus produced a variation of about two years in mental age. Our observations are in harmony with those made by Rotch and others. Rotch cites an instance of three boys of the third grade. Their chronological ages were seven, eight and nine respectively. Thus, in mental ability, so far as could be judged from their school work, they were about equal, whereas in chronological age they differed considerably. The Rontgen pictures showed them all to be equally old anatomically, indicating that it is the ana- tomical age, rather than the chronological, which corre- sponds with mental ability. That mental age is related to anatomical is shown not only by its relation to skeletal development but by its rela- tion to the development of the teeth — as discovered by Bean, in a study of the children in the public schools of Ann Arbor, Michigan. Bean called that grade in which were found the majority of children of any given age the modal grade for that age. He then classified the children of all ages from seven to fourteen inclusive into three groups: those who were in the modal grade, those who were above it, and those who were below it. He sums up ii6 ANATOMICAL AGE his findings in the statement that children in the modal grade have an average of eight-tenths of a tooth less than those who are abcwe the modal grade, but nine-tenths of a tooth more than those who are below the modal grade. ^^ The relation of anatomical age to mental age is seen also in the relationship of pubescence to scholarship, on which very decisive data have been gathered by Cramp- ton.^- He shows that boys of the same chronological age group differ with respect to pubescence according to the high school term which they have reached. For exam- ple, among boys between the chronological ages of four- teen and fourteen and a half, the percentage of pre-pubes- cents in the more advanced terms is much less than that in the hrst term. The relation between scholarship and pubescence in these boys is shown in the following table, which is typical of the results obtained with other age groups : Relation of Pubescence to Scholarship in Boys Averaging 14.25 Years in Chronological Age High School Percentage of Term pre-pubcscents First 42.9 Second 2,7.^ Third 30.4 Fourth and Fifth 16.7 Crampton also compared post-pubescents with pre- pubescents of each age with respect to the percentage gaining promotion or failure at the end of the term. For each age group he found that the percentage gaining pro- motion was from seven to ten per cent, greater for the post-pubescents than for the pre-pubescents. The preceding studies show that in whatever manner " Op. cit., p. 613. ""Physiological Age," Section II. Amcrkan Physical Educa- tion Rdnnew, vol. xiii, 1908, pp. 224-227. HEIGHT AND WEIGHT 117 we measure anatomical age, we find it correlated with mental ability. We must conclude, therefore, that the development of the brain and of intelligence advances or lags with acceleration or retardation of general lx)dily development. Whether the brightness of a child is high or low, the rapidity with which he completes his mental growth is correlated with the rapidity of his anatomical development. Relation of Height and Weight to Anatomical Age and to Mental Ability.-— All investigators have found that height and weight are much more closely related to anatomical age than to chronological age. This is but natural. The more advanced a child's physical develop- ment, the taller and heavier will he be. Thus, Crampton found that children of the same age with a full set of permanent canines averaged from five to seventeen pounds more in weight and from one-half an inch to three inches more in height than those with none.^^ He found, similarly, that post-pubescents average twenty-four to thirty-three, per cent, heavier than pre-pubescents of the same age.^'* We have already seen that mental ability varies with anatomical age. It is reasonable, therefore, to expect some correlation between mental ability and height and weight. Such correlation is now well confirmed. Porter found that the average weight of eleven-year-old boys in the sixth grade was ten pounds greater than the average of those of the same age in the first grade. Similar results were obtained in the case of the other age groups.^^ •'•"The Influence of Physiological Age Upon Scholarship." Psychological Clinic, vol, i, 1907, p. 120. "O/). c%t.. p. 116. "" Growth of St. Louis Children." Transactions of the Academy of Science of St. Louis, vol. vi, 1894, pp. 263-380. ii8 ANATOMICAL AGE The average height and weight of the feeble-minded is less than that of normal children, and their divergence from the normal increases with the severity of their men- tal defectiveness/^ On the other hand, exceptionally bright children average somewhat above normal children in height and weight. *In this connection, it is interesting to note that the children of professional men are taller and heavier than those of the less favored laboring class.^^ I have already called attention to the fact that child- ren of the professional classes are brighter than those of the laboring classes. It is clear, then, that a higher degree of brightness goes hand in hand with a better physical development." The Educational Value of Measurements of Ana- tomical Age. — Knowledge of anatomical age has a decided value from the standpoint of education. It is useful in the diagnosis of a child's abilities, physical and mental, in the forecasting of his future development and in planning and regulating his education. It also solves some educa- tional problems that have hitherto been puzzling. Of first importance is the use that should be made of anatomical age in deciding whether or not a child's men- tal development is normal. The problem is just how to employ anatomical age in the estimate of a child's true brightness. Brightness, as here used, is measured by the intelligence quotient; that is, by mental age divided by chronological age. The question arises, should we not substitute anatomical age for chronological age in calcu- " Wylie, " Contribution to the Study of the Growth of the Feeble- Minded in Height and Weight," Journal of Psycho-Asthcnics, vol. viii, 1903, pp. 1-7; and Goddard, "The Height and Weight of Feeble- Minded Children in American Institutions," Journal of Mental and Ncri'ous Diseases, vol. xxxix, 1015. P- 217-235. " See Baldwin, " Physical Growth and School Progress." U. S. Bureau of Education, Bulletin No. 10, 1914, pp. M4-150. MEASUREMENTS OF ANATOMICAL AGE 119 lating the intelligence quotient? The answer must be negative. The relation between anatomical age and men- tal age is not close enough to justify substituting anatomi- cal age for chronological. A large difference in anatomical age in children of the same chronological age brings about only a comparatively small difference in mental age. The solution lies in the correction of chronological age by the anatomical, not the substitution of anatomical for chronological. It is difficult at present to state exactly what correction should be made. I wish, however, to emphasize that we should not expect the average or normal child's mentality to correspond to his anatomical age, if the latter differs widely from his chronological age. All that we should expect, if the child is normal, is that his mentat age should deviate somczvhat from his chronological, in the direction of his anatomical age. If I were to estimate how large this deviation of his mental age from his chronological should be, I would say about one-third as great as the deviation of his anatomical age from his chronological. This ratio is based on the data presented earlier in this chapter, showing that differences of anatomical age amounting to as much as six years in a group of one hundred children, entailed differences in mental age of only two years. If, then, by inspection of his teeth or by a radiograph of his wrist bones, we find that a child's anatomical age is above his chronological, we should consider the child to be somewhat older chronologically than he really is; whereas, if he is retarded in anatomical age, we should consider him somewhat younger than he really is. That a knowledge of anatomical age is also of great value in preventing mental and physical overstrain, has been pointed out by a number of authorities. According 120 ANATOMICAL AGE to Rotch, a very largo i)r()[)()rti()n of the nervous and physical troubles of children are due to overstrain caused by forced conf(jrniing with general surroundings and school work not adapted to their needs. It is probably con- servative to say that when a child's anatonn'cal age is less than his chronological, attention should be devoted pri- marily lo his hcallh. Such a child, no matter how precocious he may be, should not \yc urged on in his school work, but given plenty of systematic exercise and rest, a thorough medical examination, and, if needed, medical treatment. To illnslratc moiv iui detiiil the application of a Knowledge of anatomical age, Terman may be quoted: " Let us imagine," he writes, " tw(^ girls in a fourth grade class who are a little slow in their work and alxnit the advisabilily of whose year-end promotion the teacher is in some donbt. I'oth pupils, let us say, are not so low in their marks but that they might be expected, with con- siderable extra effort , to carry the work of the following grade i f promoted. Ihit wiMild it be wise to have the child risk the extra effort this wcnild require? We cannot answer this (|nestion on the basis of weight, height, strength of gi"i|), or the presence or absence of external ])hysical defecliveness. I'.nt if radiograi)hs should reveal (hat one of the girls is a year ahead of her age in the physiological devek^pment and that the other is a year in retard, there would then be little doubt alK")Ut the wisdom of risking promotion in the fc^-mer case and denying it in the latter. A few years hence," he concludes, ** may see the installation of the Rontgcn apparatus in the hygiene departments of all cities where school medical supervision is practiced." ^^ "'•The Hygiene of llic School Child." 1014. pp. 68-60. MEASUREMENTS OF ANATOMICAL AGE 121 P>csi{lcs e'lKihliiiL'; lis belter lo appraise a child's capaci- ties, analoinieal aj;e, as I have staled, offers an ex[)lana- tioii of some iHiz/.hni;- edneational problems. One of the most halllinL;' of these, a perennial sonrce of discussion, is the fact that, ;;irls do better in school than boys. Why do i;irls oblain belter marks, fail less often and show a smaller ])ercenlai;e of elimination from school than boys? J am convinced that these evidenices of mental superiority are more than accounted for by the superior anatonn'cal ai;e of the girls. We conslantly compare girls with boys who anatomically are a year or two younger. It is nnnecessai-y and altogether groundless to assume, as is so often done, that the schools are better adapted to a girl's ty])e of nniid than to a boy's, or that the prepon- derance of women teachers in our schools gives the girls an advantage over their classmates of the opposite sex. It is necessary, however, to concede that girls are more intelligent than boys, because an advantage in anatomical age could not account for superior scholarship unless it carried with it an advantage in mental ability. Now, is it conceivable that girls are more intelligent than boys? However reluctant the contident male may be to make this admission, the facts demand it. As I have pointed out in a previous chapter, the best data at hand show that throughout the grades girls have a slightly higher mental age than boys of the same chronological age. This surprising proof, that girls arc more intelligent than boys should not be nn'sunderstood. Ciirls are more intelligent than, boys only when the comparison is l)ased, as it usually is, on chronological age. I hit allowance must be made for the greater anatomical age of the girls. To be actually thcj mental equal of the l)oys, the girls should exceed them in mental age by at least one-third as much 122 ANATOMICAL ACUC as llh'y do in anatomical ai/c! Now, llio average girl ol" ten is ahoiil Iwcnly-foiir nionllis ahead of the average boy ill anatomical age. One-third of twenty- f(.)ur months is eight inonlhs. To he the hoy's meiil.il t'tinal, then, the (cn-year-olil girl shonld show a mental advance of eight months over the hoy. Ccrtalnlv, she is not this far ahead of him. She (.Uks not exceed him mentally by more than four or live months. C'onsecjnently, we may conclnde that when proper allowance is made for the girls' superiority in anatomical age, they will he fonnd slightly less intelligent than the hoys. CHAPTER VII PEDAGOGICAL AGE Definition of Pedagogical Age on the Basis of " Nor- mal " Ages. — 'J'hcrc lias long existed an educational tra- dition that the proper age for entering school is six, and lliat after entrance progress should be made at the rate of one grade a year. The officers of our schools are in Ihc hahit of speaking of the age of six as the ** normal " .'ige of a child in the first grade; of seven as the normal age in the second ; and so on, allowing one additional year for each additional grade. According to this theory, (here is a normal age for each grade. A child who is over the normal age for his grade is called retarded, or hclow grade, and one who is under the normal age is called advanced, or above grade. It is the usual thing to .allow an extra year in the way of a concession to the child. In this way, a child in the first grade is not retarded unless he is eight years of age or over. To concede this additional year is no more (hail fair, i)roviding the ages are taken in the month of June or near the close of the year, as they should be. This becomes evident if we consider what is meant by the statement that a child should enter school at the age of six. The age of six may mean anything from six to seven. A child entering at the age of six may, then, be entering actually at the age of six years and eleven months. At the end of the school year, he will be nine months older — seven years and eight months. It would hardly be fair to call this child retarded. If wc neglect fractions of a year 123 124 PEDAGOGICAL AGE we cannot call a child in the tirst grade retarded unless he is eight or over. Allowing the child an extra year, we obtain the fol- lowing standard of "normal" ages for each grade: Grade Normal ages 1 6 or 7 2 7 or 8 3 8 or 9 4 .J 9 or lo 5 lo or II 6 II or 12 7 1-2 or 13 8 13 or 14 This standard is more widely accepted than any other, and in spite of its lack of precision as compared with the norms that have been established for mental tests, it is a \cry useful one. It affords the best basis for a defini- tion of pedagogical age. On this basis, we may define the pedagogical age of a child as the '' normal age " of the school grade which he has attained. Thus, if a child is in tlie fourth grade, pedagogically he is nine or ten years of age, since nine and ten are the normal ages for the fourth grade. If tlie child's chronological age happens also to be either nine or ten, the child is said to be of normal pedagogical age, or in the normal grade for his age; if his chronological age is over ten, he is pedagogi- cally retarded, or below grade; whereas if his chrono- logical age is less than nine, he is pedagogically advanced, or above grade. It is impossible to be too careful in distinguishing between the terms above grade and below grade, on the one hand, and superior and dull on the other. Recent statistical investigations have shown that the theoretically normal ages are not quite those of the average cliild. The RETARDATION AND ADVANCEMENT 125 average child does not measure up to the ideal standard. Consequently, when a child falls below the grade in which he should be according to the theoretical standard, he is not called dull nor mentally retarded. He is simply peda- gogically retarded. While many mentally retarded chil- dren are below grade, certainly many are below grade who are not mentally retarded. It is probable that the children who are above grade are, for the most part, above normal in brightness; but many children who are above normal in brightness never rank above grade. It is clear, then, that the relation between a child's mental age and his pedagogical age always has to be determined by in- vestigation ; it can never be taken for granted. The Prevalence of Pedagogical Retardation and Advancement. — The pedagogical standing of school chil- dren has been the subject of several elaborate investi- gations. Careful inquiry has been made into the number of children pedagogically normal, retarded or advanced. Very serious conditions have been discovered which raise some of the most deeply rooted problems in psychology and education, problems which we are only beginning to solve. Ayres, in a now famous investigation, found that, on the average, about one-third of all the pupils in our city public schools belong to the retarded or above age class.^ The later results of Stray er ,2 based on investigations in 384 cities, agree substantially with those of Ayres, though, to be exact, they show a slightly greater percentage of retardation. The percentage of retardation is, of course, not the same in all schools, but shows great variation. ^ Ayres, " Laggards in Our Schools," 1909, p. 3. ' Strayer, " Age and Grade Census of Schools and Colleges," United States Bureau of Education^ Bulletin, 191 1, No. 5, p. 103. 126 PEnACOOTCAL AGK Ayrcs found iUc \)c\\c\\[Ai\c .is low .is y.^ in Mod ford, Massachusetts, and .is liiidi as ;tvS in ihr rolorod scIkh^Is (d Memphis, Tcnnossct'. To understand the real exieni ol i>edaiM),i;ie.il rel.irda- tii>n, let ns consider \vhat it means to say that one-third of American city school children are retarded. It meaius that prolKd)ly a decided majority of all the children enter- inj; the schools of the averaj;e city >vill not thiish the eij;hth i;rade by the ai;e at which they shonKl " normally " tinish. A nnmhei- who heciune hadly relaided siniph' ne\cr linish the ei«;hth i;i aile at all, hnt drop ont ; and i i to this nnmlxM' are added those who ^U) finish hnl only .after they are over ai;e, we lind usually that the tt>tal is well i)ver one half the nnmher of children enterini; the SNstem. Morex)ver, many chiKlren who are retarded heciune badly retarded. CM all retariK'd chiKlren in a school system nearly half show twi> or more years of letardation. I>y conntiui^ up the total of years of retardation, consecpiently, we obtain a much lander numUM- than the niunlKM- oi children retariled. Ketarvlation bei;ins in the tnst i;rade and increases rapidly. W hen we imnc the a\eiai;e <">[ retard. ititui as one- thinl, this means that one-third of all the children are retaiiled, incliulini; even those in the tirst i;rade. who have had little time ti> become retarded. Now statistics uni- formly slu)\\ that most oi the children who once become letarded stav ret.u'ded. Mi>reover. with each ailditional i^rade. additit>nal pupils, on account i>l l.nlure. become retardcil. Consequently, the percentage of retarded chil- dren in a i;rade coutimies to increase from the tirst j^rade up io the hii;her *;rades. It wmiUl keep ou increasing;" clear up {o the eii^hth j;rade, except iov the fact that manv retarded children (far move of the retarded than oi the RE'J"ARDATION AND ADVANCEMENT 127 others j drop (jut from one of the last two or three grades. In many schools, not over (jne-half the total number enter- ing finish the eighth grade. Discouragement, economic jjressure at liome, and the failure of the truancy laws jjerniit oi an extensive process of dropping out or " ehmi- nation." This elimination, and the further fact that elimi- nation is most marked among the retarded, accounts for the tendency of retardation jjcrcentages to remain con- stant or lo sIhav a shrinkage Ix^yond the fifth or sixth grade, 'fliat tl)(^ jjerccntage of retardation reaches its maximum as early as the fifth (jr sixth grade does not mean that in tlie last two f^r three grades there are no new children added to the ranks of the retardecl. New ones are added; but they merely take the place of others who have dropped out. Contrasted with the great mass of pedagogically retarded children, the numlx^r who are pedagogically advanced is diseouragingly small. According to statistics from Minnesota schools there are eight retarded children to one who is advanced;'' and according to the statistics of Strayer '* this ratio is alxjut the average for the cities of the United States. Thus, by the prevailing school standards, there are eight times as many retarded children as advanced children. A moment's thought shows that this is an extremely serious condition. We have seen in preceding chapters that so far as mental ability is con- cerned, there are very nearly the same numlxrr of children alxjve the average as l^elow it, the same number of superior as of dull. Clearly, then, when we find eight children who are below grade to one who is alxjve, we may l>e ' F. E. Lurton, " A Study of Retardation in the Schools of Minne- sota." Science, 191 1, p. 786. * Op, cit., p. 103. 128 PEDAGOGICAL AGE sure that childiTii arc not hcini;- properly classilicd in the grades of the puhlie sehools. Hie iigures would not be so alarming if the superior children, while nol advanced in grade, were yet given dif- ferent or more diriicnlt work, or held up to higher stand- ards. This is not the ease. As a rule, if any special pro- vision at all is made for the exceptionally bright children, it is simply some arrangement whereby they can skip a gratle or a half-grade. Our schools are plainly much better adapted to the discovery of dnllness than of exceptional brightness. If a child can cover one grade's work in one year, he can keep ste[) with the procession; there is little opportu- nity to do more; and if he cannot make progress at the standard rale, he must fall behind. The standard is a little too hard for the average, so that the number who fall behind exceeds the number who remain " normal/* The system in vogue in the public schools results in a. classi- fication of children whereby the majority are retarded by the age of rifleen, and the minority normal. The exist- ence of a large class oi children superior to the normal is [)racticalh' ignored. Elimination as Studied by Age and Grade Distribu- tions. — The subject i)^ i)edagogical retardation is clovsely related to that of eliminatij>n from school. It will be well, therefore, before proceeding to a further analysis of retardation, brielly to review the facts concerning" elimina- tion. These facts are best brought (nit by the study of tables, known as age and grade distributicms, which show for an entire school or an entire school system the number of children of each age in each of the grades. A fairly typical sample is the accompanying one, vshowing the age and grade distribution of all the white children in tlie AGE AND GRADE DISTRIBUTIONS 129 regular elementary schools of the city of St. Louis at the end of the school year.^ It will be observed that the totals at the right give the number of children of each age in the school system, or, in other words, the age distribution. The totals at the bottom give the number of children in each grade, or the grade distribution. The numl>er of children who are nor- mal in age for their grade is given in numbers between the heavy staircase lines. All those above the upper heavy line are advanced, or under age, and all those below the lower heavy line are retarded, or over age. The total number of advanced children is 2001, or 3.2 per cent., while the total number of retarded is just ten times as great, 20,227, o^ 32.2 per cent. Examination of the number of children of each age, reveals that, as in the great majority of American city schools, the number of children of each age is fairly con- stant from the ages of seven to twelve inclusive. Nearly all the children are in school by the age of seven, and nearly all remain there through the age of twelve. With a stationary population, then, it would be reasonable to expect the age groups seven to twelve to remain roughly the same. The only factor to cause variation would be the population factor. This factor is regulated by two elements, death, and the number of children born in each succeeding year. The population factor tends to bring it alx)ut that there are in the community fewer twelve- year-old children than seven-year-old children. This is partly because a larger percentage of children die by the age of twelve than by the age of seven, and because, if the community has been growing, a smaller number of " Sixty-Second Annual Report of the Board of Education of the City of St. Louis, Missouri, for the year ending June 30, 1916, p. 322. 9 130 i'KDAGUGlCAL AGE J % § 4 ^ 1 1 » 1. M .7 ? 1 I l^ ^"' " ' -1 N 1 - 1 . ' .4 y. H ;'. ;! '-' 1 - :■: ''•' 1 ;- ON to - '' IN •; '-' .;: ■1 1 to q >-< IN *N ."^ ^*, t - IN ^ <^) OS 1 - vS '^ ^ - ON -t 'i o 1 - -■ v"^ - - (N fO «f :: ^^ - vK^ 1 i 1 AGE AND GRADE DISTRIBUTIONS 131 children were born in it twelve years ago than seven years ago. Ay res calculates that, on account of these two factors alone, it is reasonable to exjxxt a decrease of over 10 per cent, in the numlxir of children as we pass from seven to fourteen years of age. In the average city, children Ixrgin to drop out of school at the age of thirteen. Usually only a small percentage are eliminated at as early an age as thirteen, but during the ages of fourteen, fifteen and sixteen, elimination is extensive. After the age of sixteen, only a small frac- tion remain.^ Age distributions are often used as a basis upon which to estimate the number of children entering the school system each year. This may h>e taken as approximately equal to the average of the number at each of those ages, usually seven to twelve, at which the number tends to remain constant. For example, from the St. Louis age and grade distribution we could determine the number of white children entering the system each year for the past few years by taking the average of the age groups seven to twelve inclusive. We would thus find that the number centering each year was al^>out 7600. Turning now to the distribution of children by grades, it is interesting to note how the size of each grade compares with the numlKT known or supposed to l)e each year entering the school. As a rule the number of children in each of the first four grades is considerably greater than the numl>er entering. All the children who enter remain at least through these grades, and they pile up in numh>ers because they are held back by failure to pass. The fifth grade is typically about equal in size to the num- f>er entering; the sixth grade usually shows a falling ofif; ' See Strayer, op. cit., pp. 29-44. 132 PEDAGOGICAL AGE and bcyoiul lliis, llic si/.c tvf each j;rade doorcases until in llio oiL;lilh i;rado tlioro arc on the avorago soarooly more than hall" llio luimhor ontoring. Those ligurcs moan that AiiKMioan city schools on llio average tend to carry nearly all (heir clnldion into the fil'th grade, hut scarcely more llian hall' ol ihcni through the eighth grade. 1m-oui ouc- tcnlh to onc-lwcnliclh ol" the nuniher entering the grades reach the lonrth year ol" the high school. Cities dilTer widely, lu)\vcvcr, with respect to their ahility to hold chil- dren llnonLdi the higher grades. The Relation ot" Elimination to Pedagogical Retarda- tion. — The lacts ol elimination, which have now heen hrietly reviewed, need always to he kei)t in mind in con- sidering statistics on pedagogical retardation. It is elimi- nation alone which keei)s the percentage of retardation from mounting up to well over i"ifty per cent, in the eighth gratle. in the St. Louis schools, for which I have given an age and grade distrihiUion, it, may he noted that, as early as the fourth grade, the percentage of retarded chil- dren has climhed up to .15. At the eighth grade it has come down to Ji*^. Now shall we C(^nclude that in the upper grades, a great many retarded children catch up to grade? Si>me do, ])ut they are the exceptions. The decrease in the percentage (^f retaniation is due not to catching up, hut to elimination. It is easy t(^ show that were it not for elimination, something like 55 per cent, of the children in the eighth grade wt>uUl he retarded, simply hy determin- ing what percentage oi the numher entering fi'nish the eighth grade at or helow the normal ages. The numher entering, as ahwuly pointed out, may he taken roughly as y6oo. The munlKM- in the eighth grade at ov heUnv the normal ages, as indicated hy the age and grade distrihu- tii>n, is ;^^^S^^. ^^^ ahout .}5 per cent, of the uuiuIkm' entering. CAUvSES OF PEDAGOGICAL Rr7J^ARDAT10N 133 The rcinaining 55 per cent, eillier never reach the ei^lilli grade or else are over age when they (l(j so In the St. J.ouis .scliools, then, which show a percentage of retardation of 52.2, certainly well over half of the children fail to complete the eighth grade hefore the age of fifteen. In the average American city school, the majority of children are retarded hy the time they reach the eighth grade or would Ix; did they stay in scho(jl until they reached that grade. In Minnesota, a state-wide investiga- tion was conducted several years ago by a joint committee of school sui)erintendents and ])sychologists. On the basis of age and grade distributions, it was concluded that over seventy per cent, of the children in the schools considered in the committee's report*^ failed to complete the eighth grade by the age of fifteen. It is conservative to say of schools which show a proportion of retardation as great as the average, namely, a proportion of slightly (jver one- third, that from fifty to seventy per cent, of the children are failing to meet the theoretical cx])ectation that they will finish the eighth grade at the age of fi fteen. To attack the problem of pedagogical retardation, therefore, is to attack the ])roblem of the fifty to seventy per cent, who do not fit our present scIkxvI system. Causes of Pedagogical Retardation. — Since pedagogi- cal retardation means sim])ly a lark of adjustment l)el ween the child and the school, we may regard as responsible for its causation either the child or the school. The causes attrihutable to the school are more easily changed than lliose witliin the child. We shall consider first the less remediable causes, those resident in the child. Of these, ' Iscport f)f II1C Joint CnniiniMce, loii. The meml)crs of tlie cam miltcc wore StiixTinttMidciils S. F.. Heeler and F. E. Lurtoii, Prin- cipal A. C;. GilcUc, anrl Jlcrhcrl Woodrow. 1^4 PEDAGOGICAL AGE those which have boon most carefully investigated are sex. health and treedom from physical defects, nationality, reL;tilarity oi attendance, intellii^ence and personality. As far as sex is concerned, it has been found tiiat girls make more regular progress through the grades than boys. The lx\vs show ;i larger percentage of repeaters and a larger percentage of retardation than the girls, while a smaller proportion of boys than girls remain in school to the eighth grade/"^ These facts establish the conclusion that the school achievements of girls are better than those of bc^ys. 1 referred to this matter in the discussion of anatomical age. In that connection an explanation was otYered. It is simply that the girls develop at a more rapid rate, so that as a rtile they are anatomically older than the lx\vs of the same chronological ag'e. And their greater success in school is fundamentally due to the fact that their mental development tends to keep pace with their anatomical development. Xo doubt other factors come in, particularly in the reasons why girls show a smaller percentage of elimination than boys. The girls are not subjected to the same economic pressure to leave school in order to take a money-earning job. The relation of physical defects to intelligence and, incidentally, to success in school, has been discussed in a previous chapter. All invest ig^ations agree that stich defects are important in helping to produce failure in school work. In general, those children who fail most frequently show the largest numl^er of physical deftnrts, and their defects are usually more severe. The child with- out physical defects has a slightly greater chance than the one with them, of passing through the grades without a failure. In certain cases physical defects may be the chief cause of pedagogical retardation. This is the case, for •Ay res, op. cit., p. 157. CAUSES OF PEDAGOGICAL RETARDATION 135 example, when a child with very bad vision is not pro- vided with glasses. On the other hand, regarding retarda- tion in general, physical defects are far from being the chief factor. This is shown clearly enough by the slight difference between retarded children and normal and advanced children in the percentage having physical defects. The nationality factor entails considerable divergence of results. Certainly in some localities children of one nationality may do better than those of another. Ayres concludes from his study of children of different nationali- ties in the New York City schools, that children of dif- ferent nationalities differ radically as to ability in school work. In Minneapolis, w^here there are a large number of children of Swedish and Norwegian parentage, as well as a fair sprinkling of Bohemian, English, French, Irish, Polish and German, nationality appears to be an almost negligible factor. A tabulation of the ages and grades of two thousand children representing all these nationali- ties as well as those who gave their parentage as American, showed no reliable difference as regards nationality.^ There is even disagreement concerning the importance in school success of ability to use the English language. Ayres writes that, '' Wherever studies have been made of the progress of children through the grades, it has been found that ignorance of the English language does not constitute a serious handicap." ^^ In support of this con- clusion, he cites the experience of the department of edu- cation of Porto Rico in changing its schools from the Spanish to the English basis. The change, it is alleged, *This data was R-athered in the course of a study of the mental associations of children. A list of the nationalities represented will be found in " Children's Association Frequency Tables," by Woodrow and Lowell. Psychological Monographs, No. 97, 1916, pp. 31-32. Op. cit., p. 116. 130 PEDAGOGICAL AGE was effected with little or no loss of time on the part of the pupils. Ayres' position on this point seems to accord with the lindings of tlie majority of investigators, though not with all of them. On the whole, the evidence found in the schools indicates a speedy assimilation of the foreign element, so that, althougli here and there nationality and ignorance of English may be a cause of failure in school, it is one which in most localities is not ver}' serious, and which in the long run will eliminate itself. The importance of regular attendance is emphasized by all students of pedagogical retardation. It is obvious that failure to attend school means failure to l)enefit by the instruction given therein. We do not need statistics to prove that absence from scliool is an important cause of failure and pedagogical retardation: but it is surprising what an enormous amount of absence from school the statistics prove to exist. An examination of school ropi^rts led Ayres to conclude that less than three-fourths of the children in our cities continue in attendance as much as three-fourths of the school year. Examination of school records shows that there is a certain minimum number of days of absence, which if exceedevi. nearly always results in failure. In the ^linneapolis schools, absence of ten to twenty days in a half-year, or even twenty to thirty days, may not result in failure, but absence totalling more than this is almost sure to do so. Now absence of more than thirty days in a half year is quite frequent, and since it almost certainly means failure, it is clear that a considerable proportion of pedagogical retar- dation, perhaps as much as fifteen per cent, can be attrib- uted solely to irregular attendance. Of course a much larger percentage is due to it in some part. Turning now to the factor of the child's intelligence CAUSES OF PEDAGOGICAL RETARDATION 137 and character, we find ourselves facing unquestionably the main causes of failure in school, in so far as these causes lie within the child. Whether intelligence, as such, or certain traits of character more or less separable from intelligence are the more important, it is hard to say ; but probably intelligence is the fundamental factor. So true is it that pedagogical standing is dependent upon intelli- gence, that a high correlation between the two is often set up as one of the main tests of the soundness of any method for the measurement of intelligence.^^ Grade standing and intelligence standing by no means run paral- lel, partly because of faulty classification of children in the grades, and partly because a number of factors other than intelligence have a great deal to do with pedagogical standing; but there is no single factor that has been shown to have anything like as high a correlation with pedagogical age as has mental age. It is clear that for each grade there is a certain mini- mal mental age, which the pupil must reach if he is to have a very good chance of success. For example, a child of mental age nine has not much chance of passing the fifth grade, at least without repeating it. As a reason- able minimum he should have a mental age of ten; and to have a really good chance of passing he should have a mental age of eleven. In general, to have a reasonable chance of success in the grade which is normal for his age, a child should not be much retarded mentally. His mental age should not be much below his chronological. A considerable percentage of children have a mental age less than their chronological, and so are in danger of becoming pedagogically retarded. At first, their mental age may not be low enough to fall below the requirements " See Chapter II, pp. 33 and 34. 138 PEDAGOGICAL AGE of the grade normal for their age. But, as we have seen, the retardation of a mentally retarded child, when meas- ured in terms of months or years, increases as the child grows older. Consequently, as children grow older a con- stantly increasing number must come to have a mental age too low for successful work in the grade which corre- sponds to their chronological age; and so a constantly increasing number will become pedagogically retarded. Children who have once failed in a grade because their mental age has fallen below the requirements, although they may still grow mentally and so in the course of years make another grade or two, will tend to fall farther and farther behind. Their mental quotient tends to remain constant, but their mental retardation, measured in years, tends to increase with age. Consequently their pedagogical retardation tends to increase until at last they drop out of school. Concerning the influence of character or personality, there exists very little accurate data. On general princi- ples there is every reason to suppose that success in school, like success in life, depends largely on conscientious and persistent application, upon industry and the ability for hard work, on the interest and enthusiasm brought to bear on the work, and even upon personal manners and appearance and ease of speech and action in the presence of others. Many of these traits no doubt affect the results of our measurements of intelligence, and to such extent as they do so, form a part of intelligence. On the other hand, they depend considerably upon the individual's emotional nature. For example, a child may take a dislike to one teacher and be friendly to another. Such factors escape any methods so far devised for their measurement. For the present, we must rest content with the knowledge REMEDIAL MEASURES 139 that there are a great many emotional characteristics and traits of character which are certainly vastly important, and to which the teacher and all those interested in the child's success must give the greatest consideration. Remedial Measures. — Having considered some of the main causes of retardation in so far as they consist in traits of child nature, we should, logically, proceed to point out the causes lying within the school. To recognize a cause of retardation in the school, however, means to recognize something which should be changed. It is by changes in the school that the problem of pedagogical retardation must be solved. Child nature can be changed but little ; and even this little has to be accomplished mainly by changes in education, and so by changes in the school. Consequently, instead of an abstract discussion of causes of pedagogical retardation in the school, I shall endeavor to make my criticism constructive by considering the more practical question of the changes that should be made in the school in order to meet the situation. Obviously there is no need for changing anything which is not to some extent a cause of the present unsatisfactory conditions. The^roblern of decreasing retardation in the schools is merely a part of the more general one of adapting educa- ■ tion to the capacities of children. It is a mistake to adopt, for the benefit of the child who fails, any measures that interfere with the amount of attention given to the brighter child, or to make special provision for the failing child without at the same time making special provision for the exceptionally bright child. To all children, bright or dull, the community is under the same obligation — that of determining the capacities of each one and developing them to the point of greatest possible serviceableness. Some persons, perhaps, imbued with the importance 140 PEDAGOGICAL AGE of paying more attention to the superior children might ask, " Why bother at all about failure? Why not simply have the child who fails take the work of the grade over and over until he passes it? After all, is this child not receiving as high an education as his intelligence and zeal will permit? " It is true that, in many cases, the child is receiving about all the education he can digest of the sort offered. The point to be kept in mind, however, is that "^^7//t' failing child is not receiving the rigJit kind of edu- cation. The real question is whether these children who /fail should not be offered work dift'erent in kind and / taught by different methods, in which they would not fail ' — in short, work to whicli they are better adapted. A chihVs failure to pass is merely a failure on the part of the educational procedure used to produce the expected restdt. Each failure constitutes a demand for education along new lines. Education must avoid doing the spiritual injury of branding the child a failure. Instead, it must cultivate the spirit of initiative and self-reliance, and the satisfaction and desire for further achievement which result ivom progress and the taste of success. The edu- cation that breeds these qualities will be the one which develops those capacities that the child does ])ossess, which finds some work in whicli the child will not fail and which, by training in this Avork, guides the child into a life of nia:ximal usefuliiess. The problem of changing the existing system in any city so as better to meet the needs of the children is always an exceetlingiy complex one, even aside from questions of expense. It is hard to name any one change that of itself will produce much improvement. A change in any one respect usually calls for other changes, upon which it depends for its success or failure. REMEDIAL MEASURES 141 Of all the measures that could be suggested, none lies so close at hand as a simplification of the curriculum. By simplification is meant a reduction in the amount of work that all the children, exclusive of the feeble-minded, are expected to take in common. Simplification is accom- plished by a stricter interpretation of what are the essen- tials, and a strict limitation of the common program to these essentials. Does simplification mean lowering of standards? If it does, it will do no good ; for while it may produce less failure, it will bring about more holding back of the bright pupils. A radically simplified curriculum should not, however, result in a lowering of standards. Its very meagreness should serve to emphasize the fact that addi- tional work is essential. It allows more time to be devoted to this additional work, and more adaptation of this work to the individual needs of the pupils. The simpler the program for all pupils in common, the easier it is to make clear the necessity and to provide the time and facilities for additional individual work. The individual work for the intellectually less able pupils should be in the line of practical occupations, such as manual training, sew- ing and gardening; for the more able it should consist of more intensive work along the same lines as the com- mon program, as well as of additional academic subjects and additional practical or occupational subjects. Prop- erly interpreting its advocates, then, simplification does not mean less work for anybody. Primarily it means simply different work for the less able and the more able chil- dren of each grade with a consequent reduction in the amount of work in common. Changes in the direction of simplification should be accompanied by a more just and accurate system of grading 142 PEDAGOGICAL AGE pupils. Great progress li.'is Incn made in recent years by (loinj;- away with the old lock-slc]) sysleni and installing a syslnn of rates of jirogress wliich vary to suit the pupils h'ornKMly, in a vast majority of our towns and cities, a child who failed in one or two subjects had to repeat the entire year's work. Nowadays, it is common to divide the years' work into at least two vScmesters. Many recom- mend the further step of grading and j)r()moting the children separately in each subject, after the manner of hii;h schools, C()lU\i;cs and universities, lulucational measm-emenls have shown that even under the present grade system the averai;e child is often so much more capable in, some subjects than in others, that he really bclouj^s in dilTercnt grades in different subjects. For example, a fifth grade child, when tested by the modern mcasming scales,'" may be found below the fourth grade averai;e in handwriting, and at the same lime above the sixth i^rade average in composition. Why, then, should such a. child not be taking writing with fourth-grade pupils and composition with sixth grade ])upils? It is already customary to jirovide si)ecial teachers and special classes in drawing, sini;ing, writing, cooking, sewing and manual training. Trogress appears to lie in the direction of fur- ther organization of instruction by subjects, particularly in the upper grades. Coupled with the tendency towards greater accuracy in grading, is the tendency towards the multiplication of special classes and ])ara11cl courses. There has been a strik- ing increase in the number of auxiliary classes for feeble- minded children. There has also been a movement for " For description of these scales, see Starch. " Educational Meas- lu-cnioiils." 1016; Monroe and others, "Educational Tests and Meas- ureinents." i<)i7; and Chapman and Rush, "The Scientific Measure- ment of Classroom rrocUu-ts," 1017. REMEDIAL MI^ASURES 143 the provision, in the nppcr ^nidcs, of special classes for exceptionally bright children, and also for the j)rovision of classes for pedagogically retarded children, usually children, who are dull or backward. Further, the need for parallel courses is more and more being recognized. In some cases, these parallel courses are simply devices which permit different pupils to cover the same work in different i)erio(ls of time. For example, the work of the last five grades may be divided into two halves, and the grades arranged so that each half may be taken by the brighter children in two years, and by the slower ones in three years. More commonly, however, the parallel courses differ in character. One course usually sticks close to the traditional program, whereas the other is mainly industrial and vocational in nature and appeals mainly to those who are to enter commercial or industrial work upon reaching the age limit of compulsory attend- ance. These industrial and commercial courses, it is claimed, arc very valuable in preventing the early elimina- tion of retarded children. In farming districts, courses in preparation for agricultural life are also of great value, and often fit children with whom the traditional cur- riculum fails. So far we have discussed mainly changes in curriculum and school organization as being necessary to co[)e with, the evils of ])edagogical retardation. There are other administrative measures, however, that are im])ortrnit and that aim directly at two of the causes of failure which have been attributed to the child rather than the school. One of these causes is bad physical condition; the other, poor attendance. Irregular attendance, experience shows, can be suc- cessfully combated. The main things necessary are an 144 PEDAGOGICAL AGE accurate, annual, school census, that is, a census of all children in the community who are of school age, and an efficient enforcing of the truant laws by the truant officers. That there has been marked improvement in school attend- ance in recent years is indicated by the great reduction in illiteracy. In 1900, of all children in the United States from 10 to 14 years of age, there were 42 in every 1000 who could neither read nor write. In 19 10, there were only 22 per 1000. In all probability the federal census of 1920 will show a still further reduction in the percent- age of illiterates. To the physical condition of children, there is no doubt that there should be paid even greater attention than at present. In many rural communities conditions are little short of scandalous. The whole movement towards spec- ialized forms of training to meet the special needs of pupils must be accompanied by a greater concern in this matter. It must lead to more care for the heating, venti- lating and cleanliness of school buildings; also to systematic courses in physical culture and drill as well as to supervised play ; and to the universal adoption of a system of medical inspection by which the physical ail- ments and abnormalities, that hinder health and happiness as well as school progress, shall not only be detected and reported, but corrected. It should be noted, however, that better physical care, like better methods of teaching, will help the children who are above grade as well as those who are below grade, since the latter are only slightly more defective physically than the former. This, of course, is a greater reason for doing all that is possible ; but it follows that the problem of meeting the needs of children of different degrees of ability will by no means be solved simply by better atten- REMEDIAL MEASURES 145 tion to the physical side. If it enables a larger number of pupils to keep up to grade it will at the same time increase the number who should be above grade, and therefore make the problem of proper provision for the abler children more acute. If better health will enable a dull child to succeed with the present curriculum, it will enable a superior child to do more than to succeed with that same curriculum ; and to hold the superior child down to a course that is too easy for him is as great a mistake as to give a dull child a course of study that fails because it is too hard. The same considerations apply here as to improved methods of teaching. If better teaching can enable a pedagogically retarded child to come up to grade, what can it not do' for the normal or pedagogic- ally advanced child ? Whenever a child's actual attainments are normal or above normal, and yet lag behind his possible attainments, there exists what we may term invisible retardation. Bet- ter care of health and better teaching technique, both of which are imperative, may help to reduce the amount of pedagogical retardation, but they will not go far in solving the general problem of adaptation of education to the needs of the child, simply because to very nearly the same extent that they alleviate pedagogical retardation they aggravate what we have called invisible retardation. And invisible retardation of an able child is fully as serious as the more apparent retardation of the child who is below grade. The preceding discussion should make it clear that the problems arising from the facts of pedagogical age are problems of school administration. Failure should be thought of not as failure on the part of the child, but as failure of school authorities to provide the proper educa- 10 146 PEDAGOGICAL AGE tion. Pedagogical retardation, visible or invisible, means faulty administration. The problem is not the bringing of retarded children "up to grade." It is much broader and deeper tlian that. It is providing for each cliild that \ education which is best suited to him. This plainly ^requires first of all a diagnosis of the child's abilities. The efficiency of the school system depends on the degree to which the educational results agree with the diagnosis of mental ability. With a child of little mental ability, suc- cessful education means training for very humble occu- pations. With a child of exceptional mental ability, successful education means, not getting the child through eight grades in eight years or even in six years, but preparing him to be a leader in society. CHAPTER VIII SIMPLE MENTAL PROCESSES Intelligent Behavior and Mind. — Intelligence shows itself only in behavior; behavior is everything that an indi- vidual does. It includes all the activities of a child as he takes the Binet intelligence tests. It includes going to school, reading and writing, crying and laughing, and answering questions in geography and solving problems in arithmetic. Later in life it includes earning a living, by the conduct of a business, by teaching, or by the perform- ance of some other service; it includes getting married, keeping house, rearing children and providing for their future; it may mean fighting and the conduct of war, the research that leads to new inventions, and acts of charity and of worship. Behavior is the sum total of life's activi- ties; and it is by these activities that intelligence must be judged. As to the type of behavior which may be labelled intelHgent, I believe it is impossible to be more definite than to say that intelligent behavior is successful behavior. ** The essential characteristic of all intelligent action," writes Kirkpatrick, " is, from the objective point of view, that it shall be adapted to the securing of useful ends." ^ Useful or successful behavior is behavior which benefits the individual and the society to which he belongs. It may be objected that there are many widely different conceptions of what is good, and consequently many dif- ferent standards of success. But to just the extent to ^ " Genetic Psychology," 1908, p. 178. 147 148 SIMPLE MENTAL PROCESSES which this is true, there must be different types and standards of intelhgence. However, for certain practical purposes it is possible within limits to agree upon what is to be regarded as success, particularly in the case of cliildren. This is the less difficult, as intelligence means not the capacity for success along any one line of endeavor, but general capacity, the capacity which determines whether one individual would, on the average, do better than another in any and all performances in which he might conceivably be tested. Thus, a man might be eminently successful as a billiard player, or even as a musician, and yet not be above average in intelligence. Success in these special lines indicates special talents ; but whether their possessor is to be rated as above average in intelligence depends upon whether he could succeed in the majority of all desirable lines of performance better than the ordinary individual. Now, while the evidence of intelligence must consist always in behavior, the kind of behavior which is regarded as intelligent cannot occur except by the aid of mind. Highly intelligent conduct requires thought and attention, discrimination, judgment and reason. It is as impossible to be highly intelligent without a good mind as to have a good mind and remain unintelligent. Indeed, one may go so far as to say that successful performances should not be regarded as acts of intelligence unless their success is due to mental processes. When it is the result of luck, or physical strength, or good health, success is not a sign of intelligence. To be accepted as proof of the latter, it must show some signs of mental action, that is, some signs of learning, of profit from experience, and of wisdom. Intelligence, then, is the capacity for success in life in so far as success is gained by the use of mind. INTELLIGENT BEHAVIOR AND MIND 149 Since intelligence means the capacity for success in those tasks which require mental activity for their exe- cution, our next question is concerned with the nature of this mental activity. Is it possible to find some one mental process, some characteristic mental activity, upon which success depends? A number of psychologists have sought such, a fundamental process, but the diversity of their find- ings indicates that no one aspect of mind can be singled out as the essence of intelligence. Nearly every important phase of mental activity has been identified with intelligence. Thus, for Ebbinghaus, the main constituent of intellectual ability is the combin- ing activity of the mind — that is, the power to unify into meaningful wholes the haphazard and independent items of experience. For many, including Wundt,^ one of the most famous of all psychologists, the process most indis- pensable to the manifestation of intelligence is attention. It is on the basis of this power of attention, or concentra- tion, that Sollier defines the various grades of feeble- mindedness.^ With Binet, intelligence is largely a matter of sound judgment. At the same time, he Hnks it closely with the power of voluntary attention, by which he means the power to apply intensely one's mental faculties to the new situations with which he is constantly confronted.^ Stern defines intelligence as the capacity of an individual " to adjust his thinking to new requirements." ^ The ' " Elemente der Physiologischen Psychologic/' 6th ed., 1908, vol. i, pp. 378-386. ^ " Psychologic de I'idiot et de rimbecile," pp. 36-37 and 60-74. See also Consoni, " La mesure de Tattention chez les enfants faibles d'esprit." Archives de psychologie, vol. ii, 1903, p. 250. ^"Attention et adaptation." L'annee psychologique, vol. vi, 1899, pp. 393-395. ^"The Psjxhological Methods of Testing Intelligence." Trans, by G. M. Whipple, 1913', p. 3. ISO. SIMPLE MENTAL PROCESSES processes of judgment and of thought emphasized by Binet and Stem are merely aspects of reasoning abihty. This ability more than any other, perhaps, is accredited with first importance. According to Tredgold, it is defective reasoning that constitutes the chief characteristic of feeble- mindedness. Another capacity frequently emphasized, which does not differ much from attention, is the capacity for persistent effort, the capacity for steadfastly pur- suing a fixed purpose. Plainly it is impossible to find any one mental process that can be identified with intelligence. It is true, that certain mental functions, such as attention and reasoning, are more closely related to intelligence than others. It must be remembered, however, that the mind, like the body, functions to a large extent as a single organism, and that the more important mental processes involve all the others. For example, in the case of reasoning, it is clear that one's ability depends upon his knowledge; his knowledge in turn is dependent upon his perceptions and his memory, and also upon his power of attention and his interests. Again, in the case of sensory discrimination, it is impossible to distinguish between acuteness of the senses and keenness of attention. We cannot test visual acuity, for example, without testing attention ; for a per- son totally inattentive to visual impressions would to all intents and purposes be just as blind as one whose lenses were opaque. It is thus very difficult to state with precision the relative importance of the various mental processes. All mental processes influence behavior, although they do not have equal weight. Their part in intelligence is proportionate to their importance in secur- ing a successful adjustment to the problems of life. It is important to study the contribution of even the MEASURING SENSORY CAPACITY 151 simpler mental processes towards intelligent behavior. To these processes the remainder of this chapter is devoted. Ill the following one, two very fundamental processes, as- sociation and attention, are to be considered; the next takes up some of the more complex mental operations. The simpler mental capacities are : Sensory capacity, that is, the capacity for receiving sensations and discriminating between them; perception, or the observation of external objects; the capacity for imagery; and the capacity for feelings of pleasantness and unpleasantness. Methods of Measuring Sensory Capacity and Estimat- ing Its Relation to Intelligence. — In estimating an individual's sensory capacity, it is customary to use measurements of the smallest discoverable difference between two stimuli acting on the same sense organ. Thus, one test is given to determine the smallest percep- tible difference in the loudness of two sounds; another, to ascertain the smallest perceptible difference in their pitch. In the case of vision, the smallest noticeable differ- ence in brightness between two grays may be determined, or in the tone, or hue, of two colors. The accuracy of spatial discrimination is also studied, as in the visual acuity test, already described, or in tests of ability to discriminate length. To measure the fineness of the sense of touch, it is common to use the smallest distance which may separate two compass points applied to the skin and yet permit of their being recognized as two. This distance is known as the threshold for the discrimination of two points. Another test is the measurement of the smallest noticeable difference between two weights, and still another in the amount of pressure required on the skin to produce a sensation of pain. All of these sensory tests have been used in the study of the relation of sensory 152 SIMPLE MENTAL PROCESSES discrimination to intelligence, a relation which, because of its bearing upon sense training as well as many other problems, has been the object of a long series of experi- mental investigations and of much discussion. In such investigations, intelligence has usually been graded by taking the average score in a large number of mental tests, or by the average of school marks, or by estimates of intelligence on the part of teachers or others, or by several of these methods combined. The procedures employed in the measurement of the fineness of sensory discrimination have varied greatly, but on the whole, they have been fairly accurate.^ In order to measure the closeness of relationship between the capacity of sensory discrimination and intelli- gence, it is necessary to obtain measures of each, for a large number of individuals, preferably of the same age and sex. These measures are arranged in two columns, each number in a column representing the sensory capacity of one individual, and a corresponding number in the other column, his intelligence. To ascertain the relation- ship between sensory capacity and intelligence, then, it is necessary merely to determine the extent to which the numbers of one column rise or fall in harmony with those corresponding in the other column. This is accomplished by means of a mathematical formula, which works out in such a way that if the numbers of one column run perfectly parallel with those of the other, a correlation of one hundred per cent, is obtained, whereas if there is no relationship between the two columns of numbers a correlation of zero will be obtained. " For a detailed account of methods of testing sensory discrimi- nation, see Whipple, " Manual of Mental and Physical Tests," 2d ed., 1914, part i, pp. 161-261. MEASURING SENSORY CAPACITY 153 Any correlational percentage above zero and less than a hundred means that there is some correspondence between the two traits measured, but not a perfect one. For example, consider the relationship between the ability to add and the ability to multiply. Let us suppose that we have secured, by the aid of addition and multiplication tests, two rankings of all the pupils of a class, one ranking arranging them in the order of their ability in addition, from the best to the worst, and the other arranging them in the order of their ability in multiplication. If the place of a child in one list was, as a rule, quite different from that which he occupied in the other, so that the two lists showed no more correspondence than would two lists made by drawing the names out of a hat, then the correla- tion between the two abilities would be zero. On the other hand, if the standing of the children in one list resembled their standing in the other list, we could say that there ex- isted a correlation between the ability to addand the ability to multiply. The closer the resemblance in the standings of the children in the two lists, the higher the percentage of correlation. Were the standings in the two lists identi- cal, the correlation would) be perfect, or one hundred per cent. Lastly, and simply for the sake of illustration, should we find that the higher a child's rank in one list the lower it was in the other, we would say that the correlation was negative. Negative correlations, like positive, may vary all the way from zero to one hundred per cent. Whenever the correlational percentage is less than one hundred, it indicates that the two traits considered are in part influenced by the same factors, but that, on the other hand, each of them is to some extent determined by factors which affect it alone. For example, to take a non-psycho- 154 SIMPLE MENTAL PROCESSES logical illustration, we should find if we tabulated the price of corn and the price of pork throughout a number of years, a certain degree of correspondence or correlation, between the two. The price of one would tend to fall and rise with the price of the other. The correlation, how- ever, would be far from perfect, because, although to some extent the price of com and that of pork are deter- mined by the same factors, each is affected in part by certain factors which do not disturb the other. The Relation of Sensory Capacity to Intelligence— This outline of methods leads us to the consideration of results. The early investigations of Krueger and Spear- man"^ indicated that the correlation between sensory discrimination and intelligence was rather high. This accorded well with the emphasis so often given to sense training in the education of younger school children. Some of the theoretical conclusions of Krueger and Spearman, however, led to an investigation by Thorndike and some of his pupils.^ The sensory traits tested were accuracy in estimating the length of lines, as indicated by the capacity to draw them equaHnJength to a standard, and accuracy in estimating weight, as shown by the capa- city to reproduce a standard weight by filling a box with the necessary quantity of shot. As measures of the intelli- gence of the subjects, who were high school and normal school students, teachers' estimates of intelligence were used, along with the estimates of the intelligence of each other made by the students, and the average of their school ' " Die Korrelation zwischen verschiedenen geistigen Leistungs- Fahigkeiten." Zeitschrift fur Psychologie und Physiologic der Sinnes- organe, vol. xliv, 1907, pp. 50-114. Also Spearman, "General Intelli- gence." American Journal of Psychology, vol. xv, 1904, pp. 201-293. ' Thorndike, Lay and Dean, " The Relation of Accuracy in Sen- sory Discrimination to General Intelligence." American Journal of Psychology, vol. xx, 1909, pp. 3*^-369. SENSORY CAPACITY AND INTELLIGENCE 155 marks. The correlations between these rather crude meas- ures were much smaller than those of Krueger and Spearman, though still sufficient to indicate some slight degree of correlation between sensory discrimination and intelligence. Thus, for normal school girls, between esti- mates of length and teachers' estimates of intelligence, there was only twelve per cent, of correlation; between accuracy of weight estimation and intelligence as judged by teachers, no more than eight per cent. ; and between accuracy of weight estimation and intelligence of the girls as judged by each other, twenty- four per cent. Later investigators have tended to confirm the results of Thomdike rather than those of Spearman, on this point, in that they find but very small connection between sensory keenness and intelligence. Indeed, there seems to be no relation between intelligence and either the ability to notice small differences in weight or the ability to recog- nize as two, when applied to the skin, two points separated by a very short distance. Definite relationships appear to be established, however, for the so-called higher senses — those of vision and hearing. A very interesting study of the relation of sensory discrimination to intelligence has been made by Burt.^ His investigations were conducted among groups chosen from two schools of Oxford, England, one a superior elementary school and the other a high class preparatory school. Both groups were composed exclusively of boys ranging in age from twelve and a half to thirteen and a half years. As a measure of intelligence, Burt used the ranking of the boys by the Head-master. No assump- tions were made as to the particular kind of capacity that ' " Experimental Tests of General Intelligence." British Journal of Psychology, vol. iii, 1909, pp. 94-177. 156 SIMPLE MENTAL PROCESSES should be called intelligence. This was left to the scliool- niaster. " It was presumed," writes Burt, '' that tlie schoolmaster was the proper person, if any, to know the original meaning of intelligence, to recognize it in the concrete, and compare its various degrees, even though the psychologist might prove the proper person subse- quently to find for that meaning adequate expression, and to analyze and describe in technical terminology, the nature of the capacity denoted by it." ^^^ In view of Burt's confidence in the schoolmaster s esti- mates of intelligence, it is interesting to note the methods by which these estimates were made. In the elementary school, since the Ix^ys were in three different school grades, or standards, as they are called in England, the Head- master made three lists, based on tlie class marks, one for the boys of each standard; tliese three lists he connected by carefully dove-tailing the bottom boys of the upper standards with the top boys of the lower standard. He then thoroughly scrutinized the order, and further rear- ranged it from his private knowledge of the boys, wnth each of whom he was familiar. After an interval of several wTcks, during which he frequently took lessons with the standards in question, he revised the list. When in doubt as to the relative position of tw^o boys, his test- question w^as : " Which boy is the quickest at seeing the point of anything? " From his reputation as a judge of character, from his long personal experience of the boys concerned, and from the special interest, care and con- scientiousness with which he perfonned the task, there can be little doubt that the grading is as nearly perfect as a grading based on personal impression can be. In the preparatory school the Head-master used a '" Op. cit., p. 105. SENSORY CAPACITY AND INTELLIGENCE 157 somewhat different method. On the basis of class marks he produced two Hsts, in one of which the boys were ranked in the order of Hterary abihty, and in the other in order of mathematical ability. From a fusion of these he derived a final order of general intelligence. The sensory tests used by Burt were four in number. One was a test of touch discrimination, consisting in the determination of the threshold for the discrimination of two points; that is, of the smallest distance apart at which two simultaneously applied points yield a double sensation. A second tested weight discrimination, that is, the dis- covery of the smallest noticeable difference in a weight of 100 grams. Sound discrimination was tested by determination of the smallest perceptible difference between two pitches. The fourth test, by determining the accuracy with which a standard line of ten centimetres could be reproduced, demonstrated ability to discriminate length of lines. The tests were repeated several times, and in general were carefully applied. The percentages of correlation between these sensory tests and intelli- gence, as estimated by the Head-master, are given in the following table : CORRELATION BETWEEN INTELLIGENCE AND SENSORY KEENNESS Elementary Preparatory Bchool School Average Intelligence and touch discrimination 17 Intelligence and weight discrimination.. -.01 Intelligence and pitch discrimination 52 Intelligence and length discrimination... .51 ^ It v^ill be noted that touch sensitivity shows no rela- tion to intelligence, and that the capacity for weight discrimination bears a negative, or inverse, relation to intelligence ; pitch and length discrimination, on the other hand, have a considerable positive relation. J -.17 .00 -.20 -.10 •41 .46 .44 .47 158 SIMPLE MENTAL PROCESSES Burt's results have been corroborated by other investi- gators. Thus, Carey/ ^ who used several tests for each of the capacities of tactile, auditory and visual discrimi- nation, found that the correlation between '' practical " intelligence, as estimated by teachers, and tactile dis- crimination tests was slightly negative, whereas the correlation for discrimination of yellows — one of his visual tests — was twenty-three per cent., and for discrimi- nation of pitches — an auditory test — twenty- four per cent. Binet confirms Burt's notation of the inverse rela- tionship between intelligence and the ability to discriminate between lifted weights. He observes that imbeciles have an amazingly keen power of weight discrimination. Definitely positive correlations have been found also between intelligence and sensitivity to pain,^- as meas- ured by the amount of pressure on the ball of the thumb required to produce slight pain. Binet writes that " the threshold of sensibility to pain in the most intelligent pupils is lower than in the least intelligent ; in other words, to provoke in them a minimum of pain requires a slighter pressure." '' This finding," he continues, " compared with that which we have made upon our imbeciles, clearly shows that sensibility to pain develops with the intelli- gence ; by pain we must here understand not only a sensa- tion localized and appreciated in its intensity, but also all the psychic reverberations of this pain, the ideas and " " Factors in the Mental Processes of School Children." British Journal of Psychology, vol. viii, 191 5, pp. 86 and 88. See also Abel- son, " Mental Ability of Backward Children." British Journal of Psychology, vol. iv, 191 1, p. 303. " Binet and Simon, " L'intelligence des imbeciles," Vannie psy- chotogique, vol. xv, 1909, pp. 52-58; Carman, "Pain and Strength Measurements of 1507 School Children in Saginaw, Michigan," American Journal of Psychology, vol. x, 1899, pp. 392-398; and Swift, " Sensibility to vPain," American Journal of Psychology, vol. xi, 1900, pp. 312-317. PRIMITIVE AND ADVANCED RACES 159 emotions it provokes, which increase it like an avalanche. In truth the highest intelligences have more merit in being courageous than grosser natures ; they are in fact braver, though not by absence of fear, nor by obtuseness of the sensibilities, but by domination over a delicate sensibility." ^^ In general, then, correlation between intelligence and ability to make fine sensory discriminations is slight. The exact degree of correlation, even in the case of any one sense, will depend upon the exact kind of discrimina- tion tested. Thus, discrimination of color tones manifests a higher correlation with intelligence than does visual acuity. In general, however, keenness of vision, hearing and sensitivity to pain are valuable assets, because such sensitivity, and the capacity for discrimination of color tones, lengths of lines and tone pitches show fairly definite, though low, correlations with intelligence. On the other hand, the capacities for fine tactile discriminations and for fine discriminations between lifted weights display either no correlation or an inverse correlation with intelli- gence. Therefore, practically no relation exists between capacity for fine weight and tactile discriminations and capacity for general success. Comparison of the Senses of Primitive and Advanced Races. — However, the ability to make fine weight dis- criminations is not an undesirable capacity. This fact makes the negative correlation with intelligence an exceed- ingly interesting problem, for in general, desirable mental traits show a positive correlation with intelligence and with each other. The explanation is no doubt to be sought in man's evolutionary history. Thus it may be supposed " " The Intelligence of the Feeble-Minded," by Binet and Simon. Translation by Elizabeth S. Kite, 1916, p. 65. i6q simple mental PROCESSES that at one v^ta^c oi evolution this cajvacily, like the capa- city for hne smell discriminations in the dov;, was of great service. It may not have been exactly the capacity for makini;- Inie \veii;ht discriminations, but some capacity inseparably connected therewith, possibly some muscular or motor capacity. At this staj^e in evolution a positive correlation must have existed between capacity for weii^ht tliscrimination and intellii;"ence. Then the direction ol evolution changed. Man came to live a life in which an exceptional deveU^pment of this capacity tlid not particu- larly helj) those pi^ssessing- it to vSurvive in the strui^gle {ov existence. h>i>lution consisted in the development of other capacities. Any capacity no loni;er important in the maintenance of the species would have no giiarantee of i)reservation. Individuals possessing- it in a low degree had the same chance to survive as those possessing it in a high degree. Such a cajxicity, consequently, deterioratetl. while! other ones, more related to intelligence, were becoming per- fected. It might thus happen that those capacities, such as weight discrimination and tactile discrimination, which show no positive cori\^lation witJi intelligence in the advanced civilized races, came to be capacities in which the more intelligent individuals were often surpassed by the less intelligent, and the highly developed races by the more primitive, savage ones. That savages may excel the more intelligent races in thc^se traits which are not defmitcly correlated with intelli- gence in the white man is not merely a theoretical ciMichision. It is a fact demonstrated by numerous observati(Mis. among the most remarkable of which are those made by the Cambridge Anthropological Expedition to Torres Straits. These straits, lying l^tween British PRIMITIVE AND ADVANCED RACES i6i New Guinea and Australia, are inhabited by i'apuans. The distinguished Engh'sh psychologists who took part in the expedition set up a small psychological laboratory in a deserted missionary house on Murray Island, where for four months they conducted a num1x:r of tests among the natives. The i;>eople were sufficiently civilized to cooperate with the psychologists, although they were very primitive — nrjt far removed, indeed, from complete savagery, the first civilized teacher having landed on the island as late as 1871. In touch and weight discrimination the primitive Papuans were found superior to Englishmen. In the skin areas tested, the Murray Islanders had a threshold of tac- tile discrimination of which the value, in terms of distance l/ctwcen the two points touched, was just about one-half that of Englishmen. In other words, their power of tactile discrimination was alxjut double that of TLnglish- men. A somewhat similar^ though less striking, result, was obtained in the case of discrimination of weight; the Murray Islanders could distinguish a difference of 3.2 per cent., whereas thirty Englishmen tested in the same man- ner could discriminate only a difference of 3.9 per cent. " The power of discrimination of small differences in weight," writes McDougall, the memljer of the expedi- tion who made these tests, "apjxjars therefore to be rather more delicate in the Murray Islanders than in Englishmen." ^* Pitch discrimination, on the contrary, which has \)Qtn found to correlate positively with intelligence in white people, was markedly superior in the Englishmen. Myers, using a standard tuning-fork of 256 vibrations, found ""Reports of the Cambridge Anthropological Expedition to Torres Straits," vol. ii, part ii, 1903, p. io>8. II i62 SIMPLE MENTAL PROCESSES the barely perceptible difference in pitch for Murray Island children to average 12.5 vibrations, whereas for Scotch children of Aberdeenshire he found an average as low as 4.7 vibrations.^ ^ The pitch discrimination of the Scotch children was tlierefore better by eight vibra- tions than that of the Murray Island children. The ability of savages to hear at a distance the ticking of a watch was also inferior. Likewise, the sense of pain, keenness of which correlates wdth intelligence, was dull in the Papuans and keen in the white races. But the Papuans were not more lacking in sensitiveness to pain and acuteness of hearing than the Filipinos, the Patagonians, Africans, the Ainu and other supposedly primitive races.^^ Perception. — Passing now to the consideration of other mental capacities, we may inquire whether the capacities for perception, imagery and feeling are more closely identified with intelligence than is the capacity for sensory discrimination. It must be answered that on these functions the data are too meagre to justify very definite conclusions; but they indicate, at least, that the correlation existing between intelligence and perceptions and imagery is no higher than for sensory discrimination. Tests involving the essential part of the perception process have not as yet been employed. The important thing about a perception is that the impression derived from any object should immediately revive, and unite with, the proper associates. Thus, the sound made by an object as it moves or as it is dropped, should revive its visual appearance, its feel to the touch, and its name. "Op. cit., p. 168. The results quoted were those obtained at the children's second sitting. " See Woodworth, " Racial Differences in Mental Traits," Science, vol. xxxi, 1910. pp. 171-186; and Bruner, "The Hearing of Primitive Peoples," Archives of Psychology, No. 11, 1908. PERCEPTION 163 To test the accuracy of the perceptual processes, then, it seems necessary to use tests in which objects are pre- sented to one sense, but the judgments required are based on the associated impressions derived through other senses. For example, a number of objects might be placed before a child, such as an axe, a dish-pan, a roll of cotton, and a base-ball. Then without touching them, he should be asked to indicate the heaviest, the next heaviest, and so on down to the lightest — the experimenter arranging them in the order indicated. Again, one may show a child a number of carefully chosen, familiar objects, then have him close his eyes, and name them merely from the sound they make as they are dropped upon the table. These tests resemble the game of guessing the name of a person caught by one who is blindfolded. A great variety might be devised. How they would correlate with measures of intelligence it is impossible to say, as the necessary in- vestigations have not been made.^*^ Tests of perception so far performed show that in certain aspects, at least, perception correlates but slightly with intelligence. Illustrative results have been obtained with the cancellation test. The cancellation test consists of a number of lines of letters printed in capital letters. The letters are equally spaced and arranged In a miscellaneous, meaningless order. The subject tested takes a pencil and, running along the letters as In reading, makes a line through a designated letter every time he meets with it. Because some of the letters that should be marked may be omitted, and others may be marked by mistake, there are various "Tests of this sort are now being used successfully by Dr. Frances Lowell, of the University of Minnesota, as one of a number of group intelligence tests. x64 SlMTLi: MI:N TAL TROCKSSKS \YaYS of scoriui; tho tost other than bv takiui;- simply the numlHM' of Uitors oorrootly canoollod in tho allottod poriod. Tho rosnU doponds vory much on \\hotl\or tho test is i^ravlovl simply for speed, for aeenraey. or for Ixnh. As n\ii;ht Iv expeeted. there is a tendeney for those who work fast to Iv less aeenrate than those who work slowly. and there appears, tnrther. to Iv a teiuleney on tho part of the brii;hter ehiUlren to seek aeenraey rather tlian speed. When the test is i;raded i\m- speovl. it is likely to give a negative eorrelation with intolliiivnee. I i;':ive this test to one hnndred Minneapolis ten-year-old sehot^l children whoso intelligenee had Iven nieasnvod by Tennan's ivvision ot the r>inet-Sinion seale. Grading;- for speed onlv. I fonnd a nei;ative eorrelation with intelli- genee of -.tc>. This ai;rees with the resnlts of lUhors who have found the tost to eorrelato nog^atively w ith sehool n\arks ^^ and with tests whieh are known to eorrelato highly with intelhgenee.^'' Now it ccuvnot be denied that tho oaitcellation has sonic- tinies shown positive correlations with intelligence. It is piirticularly likely todo sowhen complicated by the require- ment of cancellation of several letters instead of merely one, and when accuracy is given due weight in the grading. On the whole, however, the resnlts obtained with this test may Ix^ regarded as indicating that neither great spet\l nor great accuracy of simple perceptual processes is of any advantage as far as intelligence is concenuxl. C^^f course this conclusion does not mean that perception is of little advantage. Both sensation and perception are indis- pensable to intelligence; b\u retinemont Ixwond a cortaiti "Whipple. ** Manual of Mental and Physical Test?.*' -?d ed.. part 1. p. 3-4- "^(cCa^. "Correlation of Some Psvcholog-ical and Educational Measurements." tot6, p. 40. LMAGERY 165 minimum, while it may Ixi of advantage in certain special pursuits, is of no aid to success in general. Imagery. — The capacity for imagery is diffjcult to investigate, but very exhaustive and painstaking studies of imagery in children have nevertheless Ix^en made. It has long \)Qcn established, by patient questioning, that children employ concrete imagery much more than do adults. Children picture to themselves the actual object, whereas adults think more in terms of symlxjls of objects, especially in mere words. The substitution of symlxjlic or abstract images for concrete ones occurs gradually, but judging from comparative studies of children and adults, the change is most marked at alx^ut the age of thirteen to fourteen. Before the age of pulx^rty the normal child thinks characteristically in concrete terms, in^ terms of particular instances. Childhood is, and should l>c, a period f(jr the acquisition of a host of detailed, accurate percep- tions and images. Greater wealth of such acquisition in childhood provides a Ixitter foundation for adult abstrac- tions. A precocious tendency towards the use of abstract thought is therefore not a promising sign. According to Meumann, a very distinguished authority, precocity in this respect is characteristic of dull children, whereas the more intelligent are lx;st represented by the tendency to use concrete images.^*^ On the relation of intelligence to clearness or distinct- ness of children's imagery, the most valuable evidence has been obtained by Carey.^^ His investigations concen- trated upon the clearness of imagery by a large number of *•" Intclligenzpriifungen an Kindern der Volkschule," Experi- mentelle Fadagogik, vol. i, 1905, p. 93. " " Factors in the Mental Processes of .School Children," part i, " Visual and Auditory Imagery." British Journal of Psychology, vol. vii, 1915, pp. 453-490. i66 SIMPLE MENTAL PROCESSES experiments, each of which required the child to make introspective judgments concerning- the clearness of his images. As an illustration of his method, we may cite the following one of eight tests used for visual imagery : 3. Think OF THE Fire Engine Can you picture the firemen ? Clearly, fairly clearly, or dimly ? Can you count them? Clearly, fairly clearly, or dimly? Can you picture the horses galloping to a fire ? Clearly, fairly clearly, or dimly? Before the experiment, some pains were taken to explain the various degrees of clearness. " Each child was asked to look at a particular object in the room and then to shut his eyes and compare the clearness of the image with that of the object, and an endeavor was made to make the meaning of the terms * clear,' * fairly clear,' and * dim,' as definite as possible. * Clear ' was to mean that the image was as plain as the object itself. ' Fairly clear ' was to mean that the image was not so plain as the object, but that it could be maintained without much effort. * Dim ' was to mean that the object could be pictured, but that it was ' shadowy,' and kept coming and going.'' The introspection of mental processes is usually considered too difficult for children, but in the task cited is fairly simple, and a special study made by Carey indicated that the introspections were sufficiently reliable for his purpose. He writes that '' not a single case occurred of a child who appeared to have failed to understand or to be unable to answer." 2- *• Op. cit, p. 4S0. IMAGERY 167 The marks obtained from these tests of imagery were compared with a ranking of children according to '' scho- lastic " and " practical " intelligence drawn up by the teachers, and also with the marks obtained in the various school subjects. The correlations were found in all cases to be very low. Between teachers' estimates of intelligence and the clearness of the different sorts of imagery, what little correlation there was tended to be negative. The correlation with marks in particular school subjects was sometimes slightly positive and sometimes slightly nega- tive, but averaged very nearly zero. Painting was the only school subject found to show a positive correlation with imagery, and even this correlation was low. The findings of Carey conform with those of other investigators. Rusk, for example, concludes that " Chil- dren who are best endowed with respect to the various forms of imagery do not, it would appear, necessarily stand highest in school." ^^ The low correlation between clearness of imagery and intelligence is not particularly difficult to understand. It is commonly assumed that every type of mental process involves the use of imagery. This may be true, although its application to thought processes is questionable. But in thinking and reasoning, imagery functions solely as a symbol. Almost any image can be used as the vehicle for any thought, just as different sounds or words are used in different languages, all to indicate the same object. Admitting, then, that imagery of some sort is indispensable in all mental operations, it must be conceded that in general the sort of imagery, visual or auditory, distinct or vague, is of little import. ^^ " Mental Association in Children." British Journal of Psychol- ogy, vol. iii, 1909-1910, p. 385. i68 SIMPLE MENTAL PROCESSES Feelings. — In addition to sensations and images it is customary to recognize a third type of elementary mental processes, namely, the feelings or " affections "of pleas- antness and unpleasantness. There is considerable dis- agreement among psychologists concerning the status which a systematic psychology should assign to these processes. The commonest opinion is that they are neither sensations nor attributes of sensations, but are a separate class of mental elements. They are usually distinguished sharply from the more complex processes called emotions — joy, grief, fear, love and anger. There is general agreement concerning the feelings on two points of importance in connection with intelligence. First, there exists a very strong, inborn tendency to do those things which give pleasure, and to avoid those which produce unpleasantness. In accordance with this tend- ency is the recognized educational principle that ** acts which are to be repeated, ends that are to be achieved, and behavior that is to be confirmed, should be made as pleasurable in their consequences as possible." ^^ The second point generally agreed upon is that pleasantness is usually the sign of an efficient and beneficial functioning of the nervous system, while unpleasantness signifies the reverse. As a rule, the pleasurable things are those which are beneficial, and the unpleasant those which are harmful. Now since the tendency is to do the pleasant things and avoid the unpleasant, it is evident that the feelings, in spite of their waywardness, of themselves afford an indis- pensable guide to correct behavior. On general grounds the feelings thus appear to play an important part in the determination of behavior, but observations to prove their correlation with intelligence ^* Colvin and Bagley, " Human Behavior," 1913, p. 91. FEELINGS 169 are few and far between. So far as they go, however, these observations indicate a very considerable relation. It has been frequently noted that feeble-minded children are below normal in the strength of their feelings, and that their feelings are often perverted, or out of harmony with the object producing them. According to the observations of Sherlock, defectiveness of the feelings is more or less proportionate to the degree of feeble-mindedness.^^ This agrees with the result noted earlier in this chapter that sensitivity to pain appears to be definitely correlated with intelligence. Pain, to be sure, is a sensation, and not the same thing as the feeling of unpleasantness; yet pain is almost invariably accompanied by unpleasantness, and sen- sitivity to it is probably closely correlated with acuteness of feeling. An interesting study of the feelings was made by Wylie, by taking advantage of the well-known fact that bodily changes invariably accompany the feelings. By means of apparatus which recorded the breathing, he stud- ied the effect upon children produced by an unpleasant sensation. The sensation used in most cases was that of the taste of quinine. The disturbance produced in the breathing was found to be very slight in imbeciles, but increased to a very marked degree as the children approached the normal in brightness. ^^ He made no ex- periments to test the effect of pleasure, but his observa- tions led him to believe that pleasantness is likewise less intense in feeble-minded children. This completes a survey of the relationship between intelligence and the elementary mental processes. Except 23 (I "The Feeble-Minded," 1911, pp. 74-76. ' Instincts and Emotions of the Feeble-Minded." Journal of Psycho-Asthenics, vol. v, 1901, p. 105. I70 vSLMri.K M1:N IWL TRCVKSSKS in the case oi the tcoliiii;s. ou which data arc vtM-y scarce, the lolatiiMJship is obviously not very close. This does not mean ihat the elcnieutaiv pr<>cesses are nuunportant. \\ ithoni the elementary processes there conKl Iv no coni- ]>le\ ones. It means merely that i;reat iTtinement in the simple mental operations is no i;teat asset. Their deveK>p- inent lK\yond a certain point is oi little i;eneral yalne. The important thini;" is the arrangement and iM'L^ani/ation of the mental processes— the interrelationships that exist Ivtween the sin\pler processes and the dei;ree of their co- operation in the carryin*; out of the more complex mental operations. Ot all the torms oi interrelatiiniship Ivtween mental processes, the two nu>st fmulamental are those ot assiH'iation and attention, now to be considered. CHAPTER IX ASSOCIATION, MEMORY AND ATTENTION If a single word is pronounccrl to a person prepared to ^ive it attention, it will at once call to his mind various related worrls and ideas. These ideas in turn will summon still other ideas, and so the process of thought will con- tinue until interrupted by some external event which catches the attention and initiates another series of ideas, 'i'he entire course of thought, including all the complex processes of imagination, judgment and reasoning may Ixi analyzed into a set of sequences of one idea upon another. 'J he occurrence of one iflea, or of any mental process in sequence upon, and as the result of, another, is called an association. Since all thinking is made up of a multi- tude of such sequences, clearly the processes of association must pervade the entire intellectual life. In its simplest forms, assrjciation is studied mainly hy two methods — that of free association and that of ajn- trolled association. In the free association method, the subject allows to come into his mind whatever associations may s[Xjntaneously arise. In the controlled association method, on the other hand, the associations of the subject are guided by instructions from the examiner. Instead of coming and going without direction, the associated ideas must stand in some prescribed relationship to each other — cause and effect, similarity, or contrast. Free Association. — The most widely used procedure in the free association method is that introduced by Jung.^ *"The Association Method." American Journal of Psychology, vol. xxi, 1 910, pp. 219-270. 171 172 ASSOCIATION, MEMORY, ATTENTION A list of common words, called stimulus words, is pro- iioniiccd to the pupil, who has been previously instructed lo reply to each word as quickly as possible with the first word that it brings to mind. The examiner gives a few carefully chosen illustrations, to begin with, somewhat in this fashion: ** When I give you a word, for example, rat, you answer just as quickly as you can with the very first word that comes into your head, no matter what it is — it may be mouse or cat, or it may be cheese, floor, hole or chimney, or something that doesn't make any sense at all, like hat or teacher. Never reply by more than a single word." The reply is made orally when the test is given to the children individually, and in writing when the test is a class experiment. Upon careful examination the replies received with a list of one hundred words arc found to l>e surprisingly interesting and illuminating. Peculiar associations gener- ally signify some peculiarity in the child's previous experi- ence, since it is a fundamental law of association that one idea cannot call up another in immediate sequence to itself unless the two have been connected in some previous experience. An analysis should consequently be made of all peculiar associations by persuading the child to recall in detail the experiences which explain them. When the tests are given individually, it is also important to note Uiosc in which the response is a long time fortli- coming, and to analyze these also, particularly to deter- mine whether or not the delay is due to any strong emotional connections. I have found this analysis of the peculiar and hesi- tating responses particularly valuable in the study of juvenile court cases. For example, I once gave the free association test to a thirteen-year-old boy accused of FREE ASSOCIATION 173 having stolen some copper wire. lie obstinately denied the theft. In a long list of stimulus words, I inserted the word copper and immediately afterwards the word wire. To the word copper, the boy replied promptly with cut — a peculiar response; l>ut at the word zvirc, he 1)ecame confused, and after about thirty seconds responded with garage. When I asked him why wire suggested to him garage, the young delinquent knew that he had betrayed himself, and immediately confessed. The results of the free association test can be adc- (|uately interpreted only with the aid of *' association frequency tables." These tables show the responses to a given stimulus word, and the numlxir of times each one occurs among the responses of one thousand individ- uals. It has been found that the same word pronounced to one thousand persons does not bring out one thousand different resp(jnses. For example, to the word dark, over four hundred out of a thousand children will respond with the word night, and to the word scissors, alx)ut eight hundred out of a thousand will respond with the word cut. Besides the most frequent response, there are always many others, so that, on the average, something over one hun- dred different responses will be obtained from one thous- and children. A frequency table shows the numlxr of children in one thousand giving each of the responses. As an illustration, I may give the following frequency table 2 compiled from the responses of Minneapolis school children from nine to twelve years of age, to the stimulus word, fun. The favorite response is play, given by 394 children. Before each response is placed the number of children giving it. ' vSee Woodrow and Lowell, " Children's Association Frcquencj, Tables." Psychological Monographs, No. 97, 19 16, p. 41. 174 ASSOCIATION, MEMORY, ATTENTION Responses to the Word Fun by One Thousand School Children 3 lx\d I down 1 ground 3 lunch 1 sew 35 ^all 1 di\n\nied 4 gun 2 shovel 7 lusoball (1 marbles 2 show 5 basketball J eat I had 2 nuMiey 4 skate 1 box 5 eatini; 10 happy 1 mueh I skates 4 ^^'■^y I enjoy 4 hapi>iness 1 1 skating lo bovs J enjoy inv: 1 7 have 8 niee 3 sled J build 1 1 hidt^-and-see k J noise J slide 1 but\ 2 tall 4 luvkey 5 stunv 1 butter J fell 2 hop J outdoors (> snowball 3 tiJ^^lit 3 hurt I outside snowballs 1 eaii 1 tinj^er 2 snowlight 1 cap 9 t'lshiui; 1 T 304 play 4 sport 4 cluvn- I food I it 34 playing 7 swimming J ehiia 15 football 4 pleasure 13 chiKlivn ; fntlie 3 jol jolly 2 rati 2 toy :?0 joy 1 nit I tO\'S 3 dark 1 2 ^:\mc (> jump 2 rt\id I delii^ht 3vS oan\es 3 reeess 1 Nery 2 delii;htful I gay i8 laugh 3 tvpo 4 dij;i;inj; 1 girl J laughed 4(> nin 2 w;ilk 2 dirt 2 girls 3 laughing I nmning I water 1 doll 4 :-;lad 1 light I well Q dolls «.) g(.XXl 5 like 4 selux>l I window 3 dvXMS 4 gixnl time • 5 lots 1 see l^^'retinoiioy tables have been eonipiled oti an elaborate scale K^th for adults "' and for ehiUlreii/ so that interest- ing;" comparisons nu\y readily be made. How striking is the ditYerence Ivtween the two groups may be seen by comparing" their commonest responses. Tltese responses arc i;iven in the accompanyini;- table tor ten words, chosen as among" the words for which the ditYerence is greatest. ' Kent and RosanotY. " .\ Study of .\ssociation in Insanity." Amcrti\iu Journal of hiSiiitity. vol. Ixvii. IQIO, Nos. 1 and 2. * Woodrow and Lowell, of", cit. FREE ASSOCIATION 175 The frequency of the commonest respr^nse of each ^roup is ^iven in itah'cs. For eax:h of the conimfjnest of one ^roup, is given in plain type the corresponding frequency (jf the other group. COMI'AKISON OK THE FREQUENCIES OF FaVOKITE RESPONSES IN O.N'E Thousand Adults and One Thousand Children StimuluH word I. Table R<;HponBC chair cat Adults 267 63 Children 16 J5^ 2. Sickness health floe tor 142 62 116 3. Man woman work 394 17 8 168 4. Girl boy dress ''\ 40 240 5. Deep shallow hole 180 32 6 257 6. Needle thread 160 72 sew 1.34 449 7. Sleep rest bed 300 75 40 351 8. Stomach forxJ ache 102 31 82 j8g 9. Doctor physician sick 213 52 6 448 10. Hand frxjt finders 204 83 130 A careful study of a list of one hundred responses, particularly when frequency tables are at hand for com- parison, is often valuable in forming an estimate of a child's intelligence. Among the special characteristics 176 ASSOCIATION. MEMORY, ATTENTION which distinguish the associations of the less intenigent from the more intelligent are tlie following live : ( i ) The less intelligent freqnently misunderstand or misinterpret the stimulus word. ( 2 ) They often fail to give a response. (3) They offer a number of senseless responses — the response word standing in no apparent relation to the stimulus word. (4) Their responses give evidence of less mental effort, being sometimes only a changed form of the stimulus word, as wish — wishing, or a meaningless sound association, as fruit — boot. (5) Their responses are likely to show^ mental inertia, of w^hich there are two main types. First, the response may consist in the simple repetition of a previous stimulus word or of a previous response word. Second, a stimulus word may start a train of ideas, which persists and detennines the succeeding responses independently of the stimulus word. Illustrat- ing this latter sort of inertia, one dull boy responded to house by ham; then to black by horse; then, w^ithout refer- ence to the stimulus w^ord, to fun by cotv; and so on. In this case the boy's mind was on the animals in the bam. and no matter what word \vas pronounced to him. he con- tinued to respond by something connected with the topic then dominating his thought. When a more quantitative expression of the integrity of the association processes is desired, that is, a measure- ment that can be expressed in numbers, the best procedure is probably that suggested by Romer.^ It involves going over the responses of each child and checking off every " favorite " response. A favorite response is the one • " Associations\'ersuche an geistig Ziiruckcfeblichenen Kindern.'* Fortschntte dcr Psychologie und ihrer Anu^ndungen, vol. iii, 1014, pp. 43-101. CONTROLLED ASSOCIATION 177 which has the highest frequency in the frequency table for the corresponding' stimulus word. According to Romer, a conspicuously small number of favorite responses indicates inferiority of intelligence. He finds that the great majority of mentally retarded children respond with a smaller number of favorite responses than do three- fourths of normal children of the same chronological age. In view of all its possibilities the free association test has been regarded as one of the most valuable single tests yet devised. Its chief worth lies in the opportunity it affords for psychological analysis, and in its picturing of a child's mental make-up. In these respects it is superior to the controlled association tests. The latter give a ranking, a number, but, like many other mental tests, little more. Controlled Association. — The controlled association tests, although they do not intimately reveal the nature of the child's mind in the manner of the free association tests, give measures very closely correlated with the child's brightness. To a certain extent, they may be regarded as tests of the organization of associations, or rather of the degree of discipline within that organization. They test the ability to perform the right mental operation at the right time, a power of obvious importance. Controlled association tests are numerous. I shall mention only two, the '' opposites " test and the " completion " test. The opposites test is one of a number, in which the subject must respond to the stimulus word not simply with whatever word occurs to him, but with a word standing in some prescribed logical relation to the stim- ulus word. In the opposites test, the response must 12 178 ASSOCIATION, MEMORY, ATTENTION consist of a ^vord meaning the exact opposite of the stimu- his word. Both accuracy and speed are involved, and therefore the test may be graded in various ways, but the simplest way is to take the number of correct opposites written in a given time. Here are two popular lists of stimulus words. The easy list, recommended by Professor Whipple, is suitable for children of lo years or younger, and the more difficult, proposed by Professor Pyle, is adapted to older children and to adults. Easy Opposites Hard Opposites high best summer weary out cloudy white patient slow careful yes stale above tender north ignorant top doubtful wet serious good reckless rich join up advance front honest long gay hot forget east calm day rare big dim love difficult Exceedingly high correlations with intelligence have been demonstrated by data obtained with this test. A number of experimenters have worked out percentages of correlation in the neighborhood of eighty.*^ Both peda- gogically retarded and feeble-minded children fall defi- "Bonser, "The Reasoning Ability of Children," 1910, p. loi; and Simpson, " Correlations of Mental Abihties," 1912, p. 75. CONTROLLED ASSOCIATION 179 nitely below the normal ones in this test, in speed as well as in quality of response J The completion test correlates as highly with intelli- gence as does the opposites test. It consists of a passage of prose in which certain words have been omitted. Each omitted word is represented by a blank, which the subject is required to fill with a word that makes good sense. The associations are thus controlled by the context. While the completion test, from the psychological point of view, may best be classified as a test of controlled association, it cannot be denied that success in it is also to some extent dependent upon imagination and linguistic ability. Almost any text can be adapted for use as a completion test. Passages from school texts already studied by the pupil, or other passages based thereon, when converted into com- pletion tests, may serve excellently in place of the ordi- nary type of examination questions. If the right words have been omitted, only a child with the requisite com- prehension of the subject will be able to fill in the blanks correctly. For psychological purposes a great variety of texts have been used. The best known of the completion tests, perhaps, are those used by Trabue as measures of the language ability of school children. There are a number of sets of these, two of which are here reproduced, the one. Scale B, for younger children, the other. Scale L, for older children.^ Only one word is to be written in each blank. ^ Squire, " Graded Alental Tests," Journal of Educational Psychol- ogy, vol. iii, 1912, p. 431; and Norsworthy, "The Psychology of Mentally Deficient Children," Archives of Psychology, No. i, 1906, pp. 59-62. ^Published and copyrighted by Teachers' College, Columbia University, New York City. iSo ASSOCIATION. :\IEMORY. ATTENTION Scale r. I. Wo liko good 1h\vs girls, J. The is barking at the cat. ,^ Tlio stars ami the will shine to-night. 4. Tinio often more valuable uK^ne;*'. 5. The poor baby as if it were sick. t>. She if she will. 7. Brothers and sisters always to help other and should nuarrel. 8 weather usually a good etYect oi\e's spirits. 0. It is very annoying to tooth-ache, often conies at the most time imaginable. 10. To friends is always the it takes. Scale L 1. 0\ildren are rude not easily win friends. 2. rienty exercise and air iiealthy and girls. ^^ In to maintain health. i>ne sliould have nourish- ing 4 happiness cannot be with money. 5. One's do always express his thoughts. t\ To to ^yait. a Iter hav ing to go very annoying. 7. It is sometimes to between two of action. 8. One can do his at one while of an- other. Memory. — Closely related to the tests of controlled association are those ordinarily nsed tor nieasurini;" niem- orv, I'Aory act c>f memory is one of controlled association. A rememlxM-ed \vord or idea comes into mind throngh association with some other idea, and memorizing" consists simplv in the formation of associations. Tims, in memor- izing- a. French- English vocabnlary. the process is one of establishing associations l>et\vcen the hVench words and the corresixMiding- English \Yords; and memory for snch a vocabnlan' is tested by giving the hVench words to detennine whether or not they call up the right association. In snch tests, the associations are even more strictly con- trolled than they are in the opposites test; for although a MEMORY i8i word may have several fairly accurate opposites, a given French word has only one correct translation. The proc- ess of memorizing a connected passage consists in forming associations l)etween each word or phrase and the succeed- ing ones. It is evident, then, that memory tests might very properly be grouped imder tests of controlled association. The difference between association tests and memory tests is that in the former the associations brought to light by the test have been formed in the individual's past experience, Ijefore the test is given to him ; whereas in the latter they are formed under the control of the examiner. The association tests appraise the organization of associa- tions formed in the past under more or less vague con- ditions, whereas memory tests reveal the power of form- ing associations by determining their strength after a definite and carefully controlled period of study. It is irrefutable that an individual may remember one class of facts or objects much better than he does others. It follows, then, that to obtain an accurate idea of any individual's memory, a number of tests must be given so as to include a considerable variety of memory mate- rials. A variety of methods should be used. In general, memory is tested by presenting to the subject for study certain memory material, and afterwards calling upon the subject to reproduce the material, which may be either visual or auditory, that is, either seen or heard, and may consist either of words or of objects, such as pictures or geometrical diagrams. The subject may reproduce this material by any possible means of expression, by speech, by writing, by drawing, by pointing, or, with musical material, by whistling, singing, or playing upon some musical instrument. Three chief types of procedure i82 ASSOCIATION, MEMORY, ATTENTION may be followed. These arc, tlie method of right asso- ciates; the method of amount retained; and the learning method. There are drawbacks as well as advantages to each of them. The method of paired associates is in some ways the most satisfactory. Words, numbers, colors, or even con- crete objects may be used as the units to be memorized. They may ]yc presented to either the eye or the ear, hence let us suppose that spoken words are to be used. Pairs of words are read to the children, who are required to repeat each pair out loud before the following pair is read. The list, which may be of any desired length, is some- times repeated more than once. Then the first words of the pairs are read alone, in a new order, and the children write down the other word of each pair. It is much like the procedure used in testing an English and foreign lan- guage vocabulary, in which each foreign word has its English associate, but differs therefrom in that both mem- ]>ers of each pair arc English words and the number of repetitions is controlled by the examiner. A good varia- tion of the method is to give a number to each of a list of words, then, after reading Ix^th the words and their numbers, to read the words only and ask the children to write down the numbers. In all cases the measure of memory is the number of second members of the pairs written correctly, that is, the numlicr of right associates. As in all memory examinations, the testing proper may be postponed to any desiral time after the original pres- entations of the material. The meth(xl of amount retained, in the broadest sense, may be said to include all the other methods. It is ordi- narily used, however, to designate the testing of memory simply by presenting material once or oftener, and then MEMORY 183 taking as the measure of memory the amount (number of words, digits or other elements) that the subject can correctly reproduce. Material commonly used consists of short prose passages of uniform difficulty throughout, or of lists of words, digits or letters. The largest num- ber of such elements that can be correctly reproduced after one presentation is known as the memory '^ span." It is determined by beginning with a short series, say of three words, easily reproduced, and gradually increasing the length of the series, one element at a time, until they are of such length that they can no longer be reproduced correctly. The greatest length of series that is reproduced correctly in two trials out of three may be taken as the memory span. The third method of measuring memory is the learning method. Somewhat difficult to control accurately, it is nevertheless a useful method. Its object is to determine the amount of study, measured either in terms of time or number of repetitions, required to learn a given material just well enough to be able to reproduce it without error. According to this method the child who can correctly recite a verse of poetry after the shortest period of study has the best memory of his class. These methods, with numerous modifications of them, have been used extensively in studying the importance of memory in respect to intelligence. A very considerable degree of correlation has been discovered. Brown tested memory for poetry and for nonsense syllables in London schools, and found correlations in the neighborhood of fifty per cent, with school marks and with general intelli- gence as estimated by teachers.^ Some investigators have " " Some Experimental Results in the Correlation of Mental Abili- ties." British Journal of Psychology, vol. iii, 1910, pp. 296-322. 1 84 ASSOCIATION, MEMORY, ATTENTION found lower,^^ others higher, ^^ correlations. In general, good memory seems more essential to a high order of intelligence than the ability to make fine sensory dis- criminations, but less important than the organization of associations as tested by the opposites test or the com- pletion test. One of the best ways of detennining the importance of any mental capacity as a factor in intelligence is to determine to what extent its impairment parallels the enfeeblement of intelligence. This method has been employed in a number of investigations of memory in the feeble-minded. Johnson may be quoted as representa- tive ; he writes of the memory span : " The results of the memory tests show that the feeble- minded fall considerably below normal children in memory span. But the memory span is so good in some cases, and the average for the majority so high, that we are led to conclude that the degree in which the memory span of feeble-minded cliildren falls below that of normal chil- dren is not commensurate with the degree in which the feeble-minded fall below normal children in general intel- ligence. Moreover, it is evident that the deficiency in attention and will-power, so proverbial in the feeble- minded child, would tend to cause the memory span to be lower than that which a normal child of equal physiologi- cal retentiveness of memory w^ouUl have. Hence we may conclude that weakness of memory, physiologically speak- ing, is not a specially prominent factor in feeble- mindedness/' ^2 " Carey, " Factors in the Mental Processes of School Children," part ii. British Journat of Psychology, vol. viii, 1915, p. 88. " Riirt, " Experimental Tests of General Intelligence." British Journal of Psychology, vol. iii, 1909, PP. I4I-T45- " " Contriljiition to the Psychology and Pedagogy of Feeble- Minded Children." Journal of Psycho- Asthenics, vol. ii, 1897, pp. 68-69. ATTENTION 185 In addition to the fact that memory is dependent upon attention and will-power, it should be noted that to a certain extent memory also involves the capacity for rational reconstruction. If certain items of a short story are remembered, an intelligent person can fill in others from imagination, and so reconstruct the story, if not in its original form, at least in such a way as to make good sense. The feeble-minded confuse a story hopelessly — so that it is a jumble of words without meaning — show- ing themselves to be very weak in the capacity for putting together in a logical way items which they may contrive to remember. It is, of course, less desirable to remember well than to remember the right things. It takes judgment to decide what is worth remembering. It is not memory in itself, but tlie use that is made thereof, which deter- mines intelligence. Consequently, it is easy to understand why memory ability, in spite of its enormous value, falls so far short of perfect correlation with intelligence. Attention. — Attention, like association, is fundamen- tal. It shares in every mental operation. It is the great steadying and directing factor of the mind. Association is the process whereby the stream of mental events con- tinues to run its course; attention is the process which directs the stream to a certain course, and thus, holding it in bounds, preserves its force and vigor, instead of allowing it to be dissipated by aimless meanderings in any direction. Good attention means devotion to the business at hand. It amounts to a surrender of the mind to the object of interest, so that the latter takes complete possession. This object of interest may be an external spectacle or the solu- tion of an abstiTise problem, but, whatever it may be, the greater the degree of attention directed to it, the greater the amount of mental energy thereby absorbed. Mental i86 ASSOCIATION, MEMORY, ATTENTION energy is monopolized by one set of mental operations, which thus reinforce themselves at the expense of all conflicting ones, and, by so doing, acquire greater strength and efficiency, manifested by the success of the actions to which they lead. The difference between good attention and bad atten- tion is primarily a matter of degree. In dull children, the degree of attention is weak; power of concentration is lacking. Inability to resist distractions accompanies this general feebleness of attention. Every little external occurrence is a successful but short-lived claimant of mental favor. There is no loyalty to any one purpose. Occasionally, but rarely, children show exceptional irregu- larity of attention, the degree of attention being good as a rule, but at times very poor. In these cases an attempt should be made to ascertain the cause of the marked irregularity. It may be necessary to consult a physician. To estimate the degree of attention of which a child is capable is exceedingly difficult. The teacher can judge of a child's attention only by his demeanor, and this is very misleading. In general, no doubt, the child who keeps his eyes on his work and appears to be absorbed in his occupation is paying better attention than one who . fidgets about. And no doubt it speaks well of the power ^of attention of the pupils in a class if it is easy to secure \ perfect quiet from them. A great difference between the second grade and the eighth grade is noticeable in the amount of scuffling of the feet while the class is atten- tively at work. But these signs at best lead to no better than a rough estimate of attention, and not to accu- rate measures. The principle on which are based most of the scientific methods for measuring attention is that the higher the degree of attention to a specified task, tlie greater the ATTENTION 187 resistance to distraction.^^ The subject's efficiency in some mental work is first measured under highly favorable conditions, and then under distraction. The greater the decrease in his efficiency as the result of distraction, the poorer his attention. The distraction may be produced by requiring the subject to carry on some other mental work simultaneously with the principal mental work, or merely by some modification in the conditions of the work, so that greater attention is required to attain the same results. The dotting test is a good illustration of this latter method, in which the distraction (or, as I prefer to say in this case, the detraction) consists simply in an increase in the difficulty of the conditions under which attention must be given. The dotting test, used by Burt upon school children,^^ is far from being purely a test of attention. It does not measure attention apart from other factors. Nevertheless it makes great demands upon attention. The task of the pupil in this test is to mark with a pencil each dot of an irregular zigzag row, printed upon a paper tape, as shown in figure No. 9. The tape is seen through a small window, past which it is carried by a small drum rotated by clock-work. The task can be made more and more diffi- cult by increasing the speed of the drum. " The subject watches and marks the dots as they appear through the window, and are carried past to his left. Each act of dotting constitutes a discrimination reaction, and a spell of dotting constitutes a series of such reactions performed at full, or nearly full, speed. . . . " See Woodrow, " The Measurement of Attention," Psychologi- cal Monographs, No. 76, 1914, p. 158; also "Outline as a Condition of Attention," Journal of Experimental Psychology, vol, i, 1916, pp. 23-39 ; and " The Faculty of Attention," ibid., vol. i, 1916, pp. 285-318. * " Experimental Tests of General Intelligence." British Journal of Psychology, vol. iii, 1909, pp. 153-157. iSS ASSOCIATION. ME^IORY, ATTENTION As the position of each dot is unknown till it is seen, each stroke has to be aimed. This requires a sustained effort of attention, the degree of effort depending upon the rate of the strokes, and therefore measured by the rate of movement of the dots upon the paper. When marked, the paper furnishes a permanent graphic record of the maintenance of the effort, failure of continuity of atten- tion being indicated by the presence of pencil marks unaimed or of dots unmarked. "^^"^ Besides the dotting test, devised especially to test the power of sustained attention. Burt used eleven other tests. .^^'\^^^^%'^\.\^' Fig. 9. — Tape used in the dotting test (filter Burt, British Journal of Psychology, vol. iii, 1909, p. 155) tests of sensor}' discrimination, motor ability, memory and association. He also secured estimates of intelligence from the school-masters. It is interesting to note that the dotting test showed the highest correlation with all the other tests, and that it also showed the highest corre- lation with estimated intelligence. In the preparatory school the correlation Ix^tween the dotting test and esti- mated intelligence was as high as eighty-four per cent. The correlation of this test with intelligence appears to decrease with practice on account of the fact that the test becomes more automatic, and consequently makes less demand upon the attention. On the basis of his results with the dotting test and "0^ cit., p. 154. ATTENTION 189 from various other considerations, Burt concludes that voluntary attention, is of all recognized psychological functions, the essential factor in general intelligence.^® Other experimenters have come to similar decisions. Abelson, from his tests on backward children, deduced that the essential nature of intellectual deficiency was probably a general lowering in the efficiency of per- formance because of the need of attention.^"^ And Dr. and Mrs. Ordahl, who gave a large number of tests to feeble-minded children of the mental ages of six, eight, and ten, were convinced that the fundamental difference between these mental ages is a matter of attention. They conclude that : " In all experiments attention is involved, and it is probable that this is the psychological process in which the levels of intelligence differ." ^^ This belief in the intimate connection between atten- tion and intelligence, held by recent experimenters, is not a new one. It has been held by a number of distinguished psychologists, such as Wundt, Sollier and Binet.^^ These authorities do not all view the process of attention in the same way, but it is probable that they are all driving at much the same fundamental fact. At present the direct experimental evidence concerning the relation of attention to intelligence is insufficient to justify final pronounce- ment. What evidence there is, however, coupled with general observation, goes to indicate that attention is as closely related to intelligence as any other known mental function. " Op. cit., p. 169. _ ^J " The Measurement of Mental Ability of Backward Children.'* British Journal of Psychology, vol. iv, 191 1, p. 311. ^""Qualitative Differences Between Levels of Intelligence in Feeble-Minded Children." Journal of Psycho-Asthenics, Monograph Supplements, vol. i, No. 2, 191 5, pp. 43 and 49. " See preceding chapter, p. 149. CHAPTER X COMPLEX MENTAL PROCESSES Tuic tonus sitiiplo and complex must be luulcrstood iu a relative seuse. V.xcn the situplcst phenomenon appears couiplex when viewed in the light of all the relationships into which it enters. It is one of the duties of science, however, to uuravel the com[)lexity always present in reality, and, by a process of abstraction which ii;iu)res many asjH^'ts of the phenomenon under investigation, to pick out those features which appear to be elementary. IH' such a i>rocess of abstraction, psychologists have distinguished certain processes as elementary. Sensations aud perceptions, images and feeling's are generally regarded as the simplest and most elementary factors oi mind: and the laws of association and attention are the fundamental principles governing* the part played by these factors in mental life. The relation of these processes to intelligence has already lx?en discussed. More complex processes remain to be considered. Among the more important of these are reasoning, emotion and will, and to these I shall mainly contine my attention. Reasoning. — Reasoning is commonly regarded as man's distinguishing mental characteristic. In spite of its preeminent importance, however, its study by experi- mental psychologists has scarcely more than begim. To attempt an exact defmition of reasoning would be beyond the scope of the present treatise. The statement that it is purposive thinking, that it consists in arriving at a mental si^lution of a problem thnmgh a more or less 190 REAvSONING 191 orderly process of association and selection of ideas, must suffice. The solution of problems is much the same thing as successful Ixihavior, and it is consec|uc^tly not altogether easy to distinguish between the capacity for reason and intelligence. IVoblems may Ixi, and often are solved, however, without the aid of reasoning. Animals solve their problems largely by trial and error, without the use of reason. Man does likewise. Some of the greatest problems have been solved by what is called intuition. The solution simply appears. One has an inspiration. Reasoning at best is elusive and treacherous, so that a man who relies upon it may actually be less successful than one with much less reasoning ability, who acts on impulse. Indeed, as reasoning becomes elafxjrate it becomes theoriz- ing. A good theory is, of course, an excellent thing, but actions based on theory are commonly distinguished from those based on observation and experience, and the latter are supp^jsed to Ixi successful. It has often been urged that human beings seldom base their conduct on their reasoning. They act instinctively in accordance with their beliefs, prejudices and wants. They use their reasoning to convince others, and, if neces- sary, themselves, that the conditions they desire are right, and that their actions are governed by wisdom. A man may act judiciously but not be able to give good reasons for his act, whereas another may act foolishly or reck- lessly but yet give excellent arguments in justification of his course. On the whole, then, reasoning capacity falls considerably short of Ixiing the same thing as intelligence. lYoblems are solved by means of mental processes other than those of reason; the value of the solutions which occur to one does not depend entirely upon whether they 192 COMPLEX MENTAL PROCESSES have been reached by a process of reasoning; and even if reason is applied to test the correctness of a solution, its operation is uncertain and erratic; and the utilization of any solution, whether based on reason or not, depends upon mental aptitudes other than reasoning capacity itself. In spite of all this, reason is one of the most valuable of the intellectual processes. Regarded in a broad way, it is dependent upon all the other mental processes. No very precise tests of reasoning ability have been devised. On the other hand, there are a great many tests in which success depends upon reasoning ability to a very considerable degree. To some extent the teacher tests reasoning ability every time she requires a pupil to solve a problem. Perhaps of all the school problems, those in arithmetic are the best for determining which pupils are the best reasoners. Of course the ability to reason about arithmetical problems alone could not be taken as a meas- ure of anybody's general ability to reason. One may reason well in arithmetic but poorly concerning human nature. It follows that a thorough diagnosis of reasoning ability can be made only on the basis of test problems chosen from many widely different fields. Aside from test problems involving* more or less formal and complete reasoning processes, in all their complexity, there are numerous simpler tests which throw light on the processes which go to make up reasoning. They may be termed tests of logical-mindedness. They include tests of analysis and synthesis, the recognition of absurdities, the ability to define, the ability to interpret a picture,^ or a stanza of poetry,^ the ability to form general *Binet and Simon, "The Intelligence of the Feeble-Minded." Translated by Kite, 1916, pp. 98-99. ' Bonser, " The Reasoning Ability of Children," 1910, p. 8. REASONING 193 principles,^ the ability to distinguish between good and bad reasons,^ and between sound and false conclusions drawn from stated premises.^ A number of these tests of logical-mindedness appear in the Binet measuring scale of intelligence, or in its various revisions. Tests of the ability to give definitions occur three times in the Binet and Simon scale. Binet points out there are three kinds of response to the request for a definition. The first is a failure to give a definition. The child remains silent or else responds with some ges- ture, such as pointing, or with merely a repetition of the word to be defined. The second kind of response is defini- tion by use. Capacity for such definitions is fairly well developed at the mental age of five. At this age the child may be expected to define by use at least four of the following six words : fork, table, chair, horse, pencil and doll. The third stage is reached at the age of eight or nine, when definitions in terms superior to use are given for at least half of a list of words like the following: balloon, tiger, football, soldier, automobile, battle -ship, potato, store. Terman classifies definitions superior to use under three headings : " ( ^) Definitions which describe the object or tell something of its nature; {b) definitions which give the substance or the materials or parts compos- ing it; and (c) those which tell what class the object belongs to or what relation it bears to other classes of objects." ^ The ability to define abstract terms is tested by one of the eleven-year tests, in which the child is asked, " Can you tell me what * pity ' means? ' Bravery,' *char- ' Terman, "The Measurement of Intelligence," pp. 310-313. * Bonser, op. cit., p. 6 . • Kuhlmann, " The Measurement of Mental Development." School Publication, Faribault, Minn., 1917, pp. 82-83. ^Op. cit., p. 221. 13 194 COMPLEX MENTAL PROCESSES ity,' 'revenge,' * justice'?" The lest is passed if three of the five words are defined satisfactorily.'^ The inabihty of children below the mental age of eight to define in terms better than by use is very striking. It is no doubt closely related to the strong tendency of all children below the age of puberty to respond by a verb in the free association test." The commonest child's response to the word table, for example, is eat, instead of the word chair — the favorite adult response; and the commonest child's response to the (piestion, ** What is a table? " is that the object is " to eat on." The following dialogue, reported by Binet,^ is a good illustration of children's definitions by use. The answers were given by a high grade imbecile, twenty-six years old chronologically and seven mentally. Q. What is .1 house? A. A house well :i house it is to rent. Q. A fork? A. That is to cat with. Q. A mama? A. She is to get things ready to eat. Q. A table? A. It is to oat on. Q. A chair ? A. It is to sit on. Q. A horse? A. It is to work. Q. A snail (edible snail)? A. It is to cat. Q. A flea? A. It is to kill. Q. Charily? A. It is those who do good in the world. Q. Justice? A. It is those who do evil. ' Kuhlmann, \op. cit., p. 60. " See Woodrow and Lowell. " Children's Association Frequency Tables." Psychohujical Monoijniphs, No. 97, 191^ PP- 78-9^- "()/>. (//./p. 101. REASONING 19S Q. Goodness? A. Ah, goodness, it is to get angry. Q. Virtue? A. (After thinking a long while) I don't know. The capacity for analysis and synthesis may be tested by asking the child to point out the way in which things differ and in which they are alike. Here is a test for seven-year intelligence : " What is the difference between : (a) A fly and a butterfly? (b) Wood and glass? (c) A stone and an egg? " The test is passed if the child indi- cates some real difference in two out of three trials. ^^ At a mental age of eight, a child should be able to state in two cases out of four some way in which the following are alike : (a) Wood and coal, (b) An apple and a peach, (c) Iron and silver. (d) A ship and an automobile. ^^ The recognition of absurdities is given as a ten-year test. It is passed if the child points out the nonsense in three of the following four statements.^^ (a) "A little boy said : * I have three brothers — Paul, Ernest, and myself ! ' " (b) "A bicycle rider, being thrown from his bicycle in an accident, struck his head against a stone and was instantly killed. They took him to the hospital, but they do not think that he will get well again." (c) " A man said: * I know a road from my house to the city, which is down hill all the way to the city, and down hill all the way back home.' " (d) " Yesterday the police found the body of a young girl cut into eighteen pieces. They believe that she killed herself.'' Terman praises the detection of absurdities as one of " Kuhlmann, op. cit., p. 36. " Kuhlmann, op. cit., p. 43. " Kuhlmann, op. cit., p. 58. 196 COMPLEX MENTAL PROCESSES the most ingenious and serviceable tests of the entire Binet scale. *' It is," he says, '* little influenced by schooling, and it comes nearer than any other to being a test of that species of mother-wit which' we call common sense."^^ There is no exact data concerning the relation of the reasoning processes to intelligence. The existing tests are inadequate and lacking in precision, and the investi- gations are far too fragmentary. We have still to learn the main types of defects; the main factors upon which success depends; the best methods of training and the amount of improvement which they can effect. Only as our knowledge on these and kindred points becomes more specific, will there be much of interest or meaning in the assumption that capacity for reasoning is above all others the distinguishing mark of intelligence. Defectiveness of reasoning ability in the feeble-minded is striking. On this point, Tredgold takes a decided stand, and the interesting observations of this eminent authority are worth quoting at length. " I regard the chief characteristic of amentia as a defect of this capacity [reasoning]. This defect reaches its maximum in the most pronounced degree of amentia, and in the majority of idiots the ability to reason is com- pletely absent. The absolute idiots would even die of starvation in the midst of food, if they were not fed. The imbeciles possess some capacity for reasoning, although of a very simple order; whilst in the feeble- minded grade [morons] the defect is still less evident. A feeble-minded child who is ignorant of money values, if offered the choice of a shilling or half-crown, may choose the latter ' because it is bigger/ Some defect, however, is present in every grade of amentia; and if I " Op. cit., p. 258. INSTINCTS AND EMOTIONS 197 were compelled to specify which particular mental ab- normality was chiefly responsible for the maladjustment of their conduct, I should certainly say it was the one we are now considering. '' I know many feeble-minded adults who are regularly employed. They are careful, industrious, and thoroughly trustworthy, but the work they are capable of and the money they can earn is only equivalent to that of a boy or girl of school age, and this for the reason that they have not sufficient intelligence to cope with any situation needing judgment, or do any work which is not of a strictly routine character. Moreover, they find it impos- sible to lay out the money they earn so as to provide themselves with the necessities of life, and in the absence of some supervision and kindly control they would rapidly come to hopeless want." ^^ Instincts and Emotions. — All of the mental processes we have so far considered are usually termed intellectual. However, it is everywhere recognized that mere intellect is not the only important requisite of successful living. Traits of temperament and character are equally essential. These are very largely matters of will and emotion, and of the interrelationship of these two functions. Both have an instinctive basis. It is indeed true that all mental processes have an instinctive basis, in that all mental processes serve to aid, to develop, or to modify the instinc- tive or inborn equipment for adjustment to environment. The fundamental aims of life are furnished by our instinc- tive wants and desires. All incentive to action, if traced back far enough, will be found to take root in instinctive tendencies. Instincts not only furnish us with aims, but in a rough way with the means of accomplishing those ""Mental Deficiency," 2d ed., 1916, pp. 116-117. 198 COMPLEX MENTAL PROCESSES aims. lUil the man at the nioroy oi his instincts is merely a iKWst. His aims remain unprecise and nnlonnnlateil, and his mothcnis c^t* accomphshing- them crude and inefli- cicni. I am, conscc|ucnily. not inchned to regard instincts as identiciU \vith intoUigence ; but that capacity tor mental processes ^vhich 1 do regard as intelhgence is prolxibly identical uith the capacity for that moditication of instincts which results in their Knter adaptation to the varying needs and problems o{ life/*' Conceding that all human activities are at Ivisis instinctive, it is generally recogni/A\l that the relationship of instincts to emotions is particularly close. All those natural and unlearned expressions of emotion which lend warnuh and interest to human life are little other than instinctive responses. And the relationship of instincts to will is nearly as close as that to emotions. I shall, conse- quently, at this point consider brietly the relation between degree of intelligence and development of instincts. So little has this latter subject been explored, that we are compelled to rely mainly on iMie invest ig-ation. that by W'ylie. cMi instincts in the feeble-minded.^^' In general, feeble-minded children show defective development oi instincts. Some instincts fail to ap].>ear, and the expression of those which are apparent is frag- mentary in character, lacking in fullness and vigor. It might be supposed that the instincts not ap^varing would tend to be those which are the latest to appear in nonnal " For elaborate discussions, see the symiv»siuin on ** Instinct and Intellijience." by C. S. Myers. C. Lloyd Morgan. H. Wildon Carr, li. K. Stout and William McDougall. Ihitish J.^unuil of Psy.-hol- ooy. vol, iii. loio; "The Relation of histinct and Intelligence," by >l." R. Marshall. 1-riiish .^M^kV- INvSTINCTS AND EMOTIONS 99 children. In general, Wylie's observations tend to confirm this supposition, although there are certain exceptions. Thus, practically all of the feeble-minded, including idiots, showed the instincts of sucking, biting, smiling, and hold- ing up the head, carrying to the mouth, sitting up, standing and walking, and laughing. Half of the idiots, eighty per cent, of the imlx^ciles, and all of the morons, displayed anger. All three grades play, in various ways, according to intelligence. Idiots play merely by " running around and handling things." Sex instincts, very often in a per- verted form, were present in one-third of the idiots, in from fifty t,o eighty per cent, of the imljeciles, and in all the morons. All other instincts were absent in the idiots. These include: Fear, present in one-half of the imlxiciles and of the morons; affection, as evidenced by the desire " to fondle and to be fondled," present in three- fourths the imfxiciles and all the morons; shame, present in one- third the imlxiciles, and all the morons ; and the instincts of imitation, curiosity, acquisitiveness and constructive- ness, all found to a greater extent among the morons than among the imbeciles. Only the morons manifested grief, joy and blushing. In spite of the general correspondence between the development of intelligence and of instincts, it would appear that in certain instances considerable discrepancy exists between mental age and what may be termed instinctive age. For example, if we may trust Wylie's observations, a child may belong in the highest grade of the feeble-minded, thus having a mental age of eight or over, and yet show an absence of the fundamental emotion of fear, which in normal children develops during the first few months ; anrl a child may have a mental age of four or five years and Ixi lacking in both fear and anger. 200 COMPLEX MENTAL PROCESSES On the other hand, the sex instincts have been noted in idiots who are apparently incapable even of hunger. It is hard to explain tJiese irregularities. Perhaps they may be understood by assuming that fear, except for some pri- mary manifestation that has been overlooked, depends upon a certain degree of intelligence, some ability to com- prehend danger, and that the sexual instinct, which we commonly think of as developing only with the age of puberty, as a matter of fact makes its appearance at a very early age, and is dependent upon physiological develop- ment merely for certain changes in the form and effective- ness of its manifestations. With these assumptions it may be said that the development of instincts in the feeble- minded, is, like their intelligence, greatly delayed; that on the whole the development of the instincts is closely correlated with that of intelligence, but that in individual cases marked discrepancies may appear between intelli- gence and instinctive equipment — between mental age and what we may term instinctive age. In spite of the imperfect development of his instincts, the feeble-minded child is more of an instinctive animal than his normal brother, for his instincts lack the control- ling influence exerted by a well-developed intelligence. " His life in many cases may be considered as purely instinctive. It is on account of these instincts that he is oftentimes a menace to himself and to his friends, and it is by reason of them that his condition is earli- est recognized, and it is to the expression and repres- sion of them that the chief part of his education must be directed." ^'^ In accordance with the general weakness of the instincts in feeble-minded children, we find as the most " Wylie, op, cit, p. io6. WILL 201 characteristic emotional character of dull and feeble- minded children an abnormal indifference. The phleg- matic temperament is the most common. This apathetic disposition is particularly characteristic of the lower grades. On the other hand, cases of exaggeration of emotions are not uncommon. An excessive excitability is found in all grades of mental retardation, but is more marked among the higher grades. Contradictory as it may seem, the same child may display both an abnormal lack and an abnormal exaggeration of emotion. He may be lacking in the finer emotions and sentiments, and at the same time suffer an increase in the grosser ones. This condition is indeed quite characteristic of persons of depleted nervous energy. They evidence little capacity i for the higher and more cheerful emotions, an inability to be joyous and enthusiastic, and yet at the same time/ are very irrita1)le and are easily aroused to such emotions as anger and gross sexual love. Mentally retarded chil- dren usually appear fairly contented with their lot, and, as often remarked, they commonly manifest a considerable degree of child-like affection. Will. — Emotions and instincts are closely related to will. The will is exerted for aims that are at bottom instinctive or emotional, in spite of the fact that this is usually not recognized by the individual as he acts. At the same time, the greatest obstacles to will are instinctive tendencies v/hich conflict with the reasoned plans that should be carried out. The conquest of disturbing in- stincts, or of any other distractions, depends largely upon the power of attention, as the latter determines largely to what extent one may stick to one plan or purpose to the exclusion of others. By will, a term used too loosely and variously, I mean very largely effective control 202 COMPLEX MENTAL PROCESSES exerted by attention and reason over natural instinctive tendencies. I do not use the term to indicate any mental process whatsoever, but merely to indicate the control of conduct by the mental processes. By a strong will, I mean that the actual behavior of an individual accords with the behavior which he anticipates and regards as desirable; that his acts are consistent with his conception of what is wise and right; that resolutions are not facilely broken; and that unreasonable, impulsive or automatic acts are properly inhibited. Defects of will may be said to be of two sorts, direct and indirect. A direct defect is weakness of will, a lacfi of persistence, an incapacity to bring about any action that requires much effort. An indirect defect is an exag- gerated automatism. The two kinds of defect are fre- quently associated. (i) Persistence. — If weakness of will is extreme, the result is simply stupor. In milder cases, actions which require any great amount of effort or endurance are avoided. There is a feeling of fatigue and lassitude which seems to prevent the individual from exerting himself. In addition, there is often a certain slowness and unsteadiness of movement, and a general lack of enthusi- asm. The accompanying mood varies between indiffer- ence and discouragement. Several tests of will power have been attempted, but necessarily, none are entirely satisfactory. They are mainly tests of the ability to persist in an action in spite of fatigue. One such test, called an achievement capacity test, was used by Fernald, resident physician at the Massa- chusetts reformatory, as one of a number of tests designed to distinguish the responsible from the irresponsible crimi- PERSISTENCE 203 nal.^^ Discussing the mental examination of reform school boys, he says : '' That function of the mind called will, persistency, determination, pluck or spunk, plays too large a part in the successes or failures of these sub- jects to be overlooked in an investigation of efficiency. It cannot be measured directly, apparently ; but it may be measured in terms of voluntary endurance of discomfort." The achievement capacity test consists in a measure- ment of the time that the subject can stand with his heels slightly off the floor. A simple device, consisting of levers attached to the plate on which the subject stands, enables him to tell by observing a pointer in front of him just how nearly his heels come to the ground. Fatigue is rapidly induced, in a natural and harmless manner, and strength of will is measured by the length of time that the subject resists this fatigue and keeps up his heels. The chief disturbing factor is the variation between dif- ferent subjects in mere physical strength. Fernald believes this factor is unimportant because the test involves those muscles whose strength most nearly corresponds with the body weight, namely, the muscles used to carry and support the body. Hence the person with stronger muscles usually has a greater weight to support. In practice, says Fernald, the theory of the test has been found valid. " No subject has fallen exhausted muscularly, but eve ^ one voluntarily stepped down and walked away, showing that the will to withstand the fatigue longer had yielded before the muscles lost power." The test was given to one hundred reform school boys, and for comparision, to students of the same age in a near- by manual training school. The average time that the heels ""The Defective Delinquent Qass, Differentiating Tests." American Journal of Insanity, vol. Ixviii, 1912, pp. 538-541. 204 COMPLEX MENTAL PROCESSES PERSISTENCE 205 were kept raised was three times as great for the normal group as for the reformatory group, being fifty-two sec- onds for the former and only seventeen for the latter. Whatever the shortcomings in the test, the results are certainly interesting. An older and better known test of the ability to per- sist in an effort in spite of fatigue is the ergograph test. By means of somewhat elaborate apparatus, the test meas- ures the ability to continue to raise a heavy weight once every second with the middle finger. The other fingers, as well as the whole forearm, are firmly clamped in a support. The weight is attached to the finger by a cord which moves over a pulley, as shown in the accompany- ing diagram (Fig. 10). A pointer, attached to the cord, scratches on the smoked paper of a rotating drum, thus producing a record of the movements of the finger in the form of ergograph curves, some of which are here reproduced. I have found the study of these ergograph curves, and of the children making them, so fascinating that I have spent many days in obtaining such curves from children in the lower grades and in special classes for the mentally retarded. Of the large number of curves obtained, the few here reproduced (Fig. 11) have been selected as typical. It should be stated that the form of curve obtained depends upon numerous conditions — the heavi- ness of the weight to be Hfted, the strength of the muscles, the length of time since the preceding trial, and so forth. The curves here presented have been selected with great care, so that they should be strictly comparable. The mental age (M.A.) and chronological age (C.A.) of each child is recorded opposite his curve, so that few explanations are necessary. The thing most typical of No. 1. C. A., 0.5 yra. M. A., 7.3 " No. 2. C. A., 10.0 yrs. M. A., 7.0 " No. 8. C. A., 7.0 yra. M. A.. 7.0 •* No. 4. C. il., 9.6 yrs. M. A., 9.3 " No. 5. C. A., 16.0 yrs. M. A.. 10.6 " Fig. II.— Children's Ergograph Curves. PERSISTENCE 207 children of low mental age, normal or feeble-minded, is that they give up after a few fairly vigorous contractions. The effort required, of course, increases very rapidly, but adults and older children, with stronger will, do not quit suddenly as soon as the effort becomes considerable ; they go on, doing the best they can, so that through a con- siderable time the curve made by the top of the record declines but gradually. Children of the mental ages of six to eight, however, give as a typical curve one which drops off with extreme suddenness after a few good con- tractions. This characteristic cessation of effort is well shown in curves Nos. 1-3. The height of the first contractions of the curves depends mainly on the size of the fingers and so is correlated more with chronological and physiological age than with mental age. It is the form of the curve, rather than its height, which is signifi- cant; and all three of the specified curves, made by chil- dren of mental age seven, show the same sudden drop. That this characteristic drop in the curve is due to a cessation of effort, and not to muscular exhaustion, is proven not only by its suddenness, but in many cases by the equally sudden reappearance of good contractions. Curve No. i represents such a case. After the finger is apparently so exhausted that it can scarcely move, it suddenly begins to contract as well as it did at the start. The contractions again suddenly cease only to rise once more. Curves showing this vacillation of will are not at all uncommon. They prove that the child is merely mak- ing spasmodic efforts and is incapable of persistence to the end. He runs no risk of exhausting himself. He is like most morons. They cannot be fatigued because they will not work long enough. Curve No. 4 shows an intermediate stage. While the 2o8 COMPLEX MENTAL PROCESSES little girl who made this curve had the sanie chronological age as the mentally retarded boy who made the typical curve No. i, she was two years ahead of him in mental age. Her curve shows not only somewhat greater strength but decidedly more perseverance. Curvx No. 5 is given mainly to show contrast. It closely resembles tlie nor- mal adult curve. The rapidly sloping part is more nearly convex, instead of extremely concave as in the case of the mental sevens. The cessation of effort is more gradual. It was made by a moron girl ten and a half years old mentally and sixteen chronologically. (2) Suggestibility and Impulse. — The ergograph curves furnish a good demonstration of the lack of sus- tained effort, and of the resulting inactivity and feeble accomplishment which are the primary symptoms of a weak will. These symptoms, however, are seldom the only ones. As the exertion of control weakens, various medianisms begin to assert themselves on their own account, and we have appearing a large variety -of more or less abnormal phenomena. These constitute what we may call the indirect symptoms, symptoms which some psychologists group under the designation of automatisms, and which, for the most part, are matters of increased sug- gestibility or exaggerated impulsiveness. As a rule the feeble-minded at any age, like young, normal diildren, are credulous and readily suggestible. This, together with their weakness of intellect, makes them the easy prey of vicious and evil characters. Various interesting methods have been devised for testing sug- gestibility. One of these is a line-copying test. The subject is shown one at a time a series of lines printed on cards. The first three form a series of regularly increasing lengths. The remainder all have the same SUGGESTIBILITY AND IMPULSE 209 leng-th as the third line. The subject is asked merely to reproduce the length of each line by drawing it on paper. The marked and regular increase in length of the first three lines serves as a suggestion that the increase will continue throughout the scries, so that the subject may continue to increase the length of his C(jpies long after the increase in length of the lines presented to him has stopped. The results sometimes obtained arc almost Fig. 12. — vShowing performance in suggestion test. The standard lines, from the third on, remained the same in length. incredible. Some children act as though they had com- pletely forgotten what they were originally told to do, and lapse into a state of mind where each line is merely a signal to draw one a little longer than the previous one. An interesting illustration is that reproduced in figure No. 12, showing the performance of a highly suggestible moron girl. Binet describes a number of other interesting and highly amusing tests of suggestibility, adapted to early mental ages. One of these is assent without motive to an 14 2IO COMPLEX MENTAL PROCESSES obscure affirmation or simply to the exclamation, " Isn't that so?" The child of seven or eight may promptly reply in the affirmative, as though assenting to the state- ment of an important fact. At later ages, toward puberty, the child remains unmoved, or betrays astonishment and asks, " What do you mean? " Binet also gives a test of a much bolder sort : " We rise, we take a chair and show it to the imbecile. Q. What is that? A. A chair. Q. Serious mistake ! It is not a chair, it is a cork-screw. (A pause.) Let us see, what is this? (and we present again the chair). A. A cork-screw. Q. Upon what are you sitting? '' A. Upon — a cork-screw. " This test succeeds invariably with all our imbeciles, even the most rebellious ; and one can believe that it would require a very low mentality to thus consent to change the name of a very familiar object. It is evident that in a company of friends one who attempted to try this experi- ment would have very little success." ^^ It should of course not be inferred that, in the preced- ing experiment, the imbecile was led to perceive the chair as a cork-screw or to believe that it was a cork-screw. He was merely led to act as though he did. Consequently this test, as other suggestion tests, merely makes trial of docility. Docility of this sort, however, as Binet insists, is a form of suggestibility. " There are," he writes, '* two forms of suggestibility which have not been sufficiently differentiated: the suggestion of hallucina- tions, of ideas, of concepts on the one hand, and the sug- gestion of acts, of words, mimicry on the other. Docility "Binet and Simon, "The Intelligence of the Feeble-Minded." Translation by Kite, 1916, p. 109. SUGGESTIBILITY AND IMPULSE 211 is a suggestibility which shows itself simply in acts, words, attitudes. . . . It is not the reason of the agent which bends, it is his will, his character. One may have suggestibility of character without having suggestibility of reason." "^^ An exaggerated automatism may show itself in impul- siveness as well as in suggestibility. Impulsiveness may be of either of two widely different types : the emotional, and the unemotional or mechanical. In the emotional type, the individual shows signs of driving power, but the power is not under control. The impulses may not be particularly strong, but they sway the conduct of the individual because of the weakened power of inhibition. In the mechanical type, we see simply the effects of the activity of an unenergetic nervous system, functioning according to whatever habits the individual has happened to acquire, with a total absence of attentive reflection or of any reasoned purpose. Of the emotional types of impulsiveness, violent dis- plays of temper are among the most common. Quarrel- ling and fighting and generally disorderly conduct, some- times criminal in nature, may be the result. In other cases, there is inability to inhibit immoral impulses. It is said that every feeble-minded girl is a potential prosti- tute. The sexual impulses may not be as strong as in the normal individual, but on account of the weakened will and heightened suggestibility they control the course of conduct. Again, the individual may be a victim of peculiar antisocial impulses. These morbid impulses dis- play great variety. Some are exceedingly serious ; a recur- rent tendency to steal, for instance, to set things on fire, ^'^ Op. cit., p. 119. 212 COMPLEX MENTAL PROCESSES to destroy property or to mutilate or kill animals or human beings. In the unemotional type of impulsiveness, the auto- matism consists in acts, often of a silly nature, repeatedly executed in a purely mechanical fashion. Children may constantly echo the movements or words of another. Bit- ing the nails, drumming on the desk v^ith the fingers, or muttering some phrase over and over again, are exceed- ingly common habits in all grades of children. Certain stereotyped performances may be persisted in day after day, and year after year. The majority of imbeciles whom I have observed show these peculiar habits. One such, whose duty it was to shove all day long a floor polisher along the hall in front of a room which I occupied one summer, had the habit, when no one was watching (so far as he knew) of taking one step forward and then one step backward, in a more or less swinging or dancing style. He continued, during this performance, to hold the handle of his floor polisher, but in such a way that the polisher itself remained stationary. I can testify that these movements were repeated without interruption for over an hour, and I suspect that as a regular thing fully one-half of this imbecile's working day was devoted to these strange exercises. CHAPTER XI MENTAL ORGANIZATION The Problem of the Interrelationship of Mental Traits. — The brightness of a child does not depend upon his abihty in any one respect. A child is by no means of superior intelligence simply because he can draw well, or because he is good at rolling a hoop or playing marbles, or even because he can learn his multiplication table with exceptionally little study. As repeatedly pointed out, intelligence is the capacity for success in performances in general. It includes all the capacities for the hundreds and thousands of different things which a human being can do. As soon as this is admitted, the question at once arises : Are all these hundreds and thousands of capacities separate? Do they vary so independently of each other, that the degree of perfection of one is in no way an index to the degree of perfection of the others? I know of no writer so extreme as to insist that there is utter lack of relationship between the different per- formances of which a human being is capable. It is true that Thorndike, one of the world's most eminent educa- tional psychologists, has been accused of taking this stand. Binet writes that according to Thorndike, the mind is a vast multitude of absolutely unlike faculties, existing side by side, but remaining rigorously independent.^ Binet's citation, however, somewhat exaggerates Thorndike's views. A more just conception of his position is given by the following quotation: '' Almost any, if not any, one * " Les idees modernes sur les enf ants," 1909, p. 242. 213 214 MENTAL ORCANIZATION (hint;" in ihc mind may happen in partial independence of ahuost any, if mU any, other thini;-." " lU)\\ever, it can hardly he denied that Thorndike at times approaches sc^methini;- very near an atomistic theory of mind, a theory, that is, that mind is merely a collection of a vast number of extremely minute functions, each of which is complete in itself, althoni;h united to others by more or less mys- terious ** bontls." .\s atoms, he uses a miscellaneous assortment of feelin<;s, acts, ** connections," ** capacities" and " abilities." This opinion considers mind to be merely an a^^i;loniera.tion or "sum ti^al " of "an individual's feelini;s and acts, of the connections Ivtween outside events and his responses thereto, and of the possibilities of having" such feelings, acts, and connections." '^ Tie holds that '* the mind is a host of highly particularized and independeiU abilities: " ** and emphasizes the independence of these innumerable mental jn'ocesses. h^ven so, Thorn- dike is far from Ix^lieving that there is no relationship or interdependence between the innumerable specific men- tal acts. Indeed, all authors have admitted some sort of interrelationship of mental pnu'csses. scmhc degree of men- tal organizaticMi or unity of mind; and it is the problem of the present chapter to discuss the nature of this organization. Three Psychological Theories of Mental Organiza- tion. — rhc problem has had a long and devious history^ which is worth briefly reviewing. Early psychology assiuned that mental processes were largely manifestations of the activities of the sotil. Starting with the distinction made by Aristotle Ix^tween the ** rational '' soul and the " animal " soul, philosophers finally arrived at the classi- *** Educational PsvchologT," UX13. p. j8. '0^ <•/■/.. 1010. p. 188. V>/>, cil., ny\\, p. 30. THEORIES OF MENTAL ORGAN IZA^ITON 215 cal triple distinction of the three faculties oi knowing, feeling, and willing/' Each oi these was a manner of ]>erforming, a mode of activity, possessed by the soul. Whenever one exj>eriencecl an emotion, his soul was exerting its faculty for feeling, and whenever one per- ceived anything, its faculty f(jr knowledge, sometimes called the faculty of cognitic^n or intellect. Of course all such explanatioTis of mental processes as faculties of the soul were unsound and futile. Very largely, how- ever, they seem, to have been intended to descrilx.* the minrl, to state the different kinds of things the mind does. 1'he three great faculties of knowing, feeling anrl willing were soon sulxlivided into many sulx>rdinate ones, until finally the number of subf acuities was quite large. The classical doctrine of the three faculties meant sim- ply this: First, that every mental act could be classified under r;ne of these three headings — intellect, feeling, and will ; second, that all the acts included under any one of these headings were due to the activity of a single factor. Thus every act of perceiving or judging was to some extent due to the functioning of one faculty or capacity. The ancient view of this faculty as a capacity of the s^ml has no significance; the fundamental thought is little modified if we substitute brain for soul; Ix^cause the crucial idea is merely that all similar mental acts derive their characteristics in part, though not entirely, from a single, unitary factor, from one condition or set of con- ditions. Thus stated, the faculty psychology contains a germ of truth ; that is why it has Ix^en " so easy to scotch, but hard to kill." After a long and flourishing existence, the faculty • See Dessoir, " Geschichte der neuere deutschen Psychologie," vol. i, pp. 196-381. 2i6 I^IENTAL ORGANIZATION psychology' finally fell into disrepute. Curiously enough, the really serious arguments against it are of two quite opposite sorts and lx)th are tenable. On the one hand, faculty psychology- is said to be at fault because it divides the mental life into isolated compartments independent of each other, whereas in reality the mental life is unitary. Man is one, not three. ** We do not tliink and only think in one moment, and will in another, and feel in yet another. There is no experience which is now^ intellective, now volitional — and at another moment, affective. The unitary experience may not he broken up thus. Any jxm*- tion of concrete experience, select it by what nile we may, is a thinking — feeling — willing experience." ^ The other objection to the faculty theory, made by men, who, like Thorndike, emphasize the relative inde- pendence of each specific mental act, is that no such thing as a faculty exists, because each act dift'ers from all the others, even when it may Ix^ classified under the same heading. It is pointed out that a person may have a good memory for faces with a lx\d one for naines : that he may listen attentively to an orchestral symphony and dream through a lecture on mathematics: that he may reason well in one line of business and poorly in another. There is no faculty of memor\' as such, these authors say. because one thing may be remembered while another is forgotten. *' There is no one memory," writes Thorndike, ^' to hold in a unifonnly tight or loose grip all the experiences of the past. There are only the particular coimections between particular mental events and others, sometimes resulting in great surety of revival, sometimes in little." " •Fletcher. "Introduction to Philosophy." 1913, p. 209. ' " Educational Psycholog}'," lOio, p. iSS. TTTEOPTF/; OF JiPAJK ACTION 217 Here, iIk.)], arc three distinct psychological thf^jries. 'I lie oldest and ixrrhaps the most influential is the doctrine (A farultics, the drjctrine that certain mental processes are alike in some import;mt respect, and inihw-n^^d, deter- mined in character, U) iV^me extent, by a sijj;^de f;u:tor. Also, there is the doctrine of unity oi mental life, which may he carried U) the point of excluding any possibility of s<:parate faculties. 'I'he third view, extensively a/lvo- caled at j)resent, is that ear:h mental pnxx*ss is s/j emphati- cally unrelated to any oIIxt that to reganl any large j-^rouji of menial pro(:ess<:s as l><:inj( controlled \)y the same factor is misleading. This doctrine cr^ntends fr^r menUil disorrj(mt"ation, and accordinr'^ I0 it. tlj<', d'-fT'c of inter- relationship 1/ttween menial ]>rocesses of the same class is not suffieient to justify any ^(roupin^ of tliem tof^ether as dep^'ud'Jil Ujjon a sinrde raj>arity. Corresponding Theories of Hrain Action. — isach of the three psyeholo;/ieal theories of mental or^anizatif>»n has its parallel the/^ry of brain. Ji/lion. The docXrmc (jf faculties, in an exaggc*rateart in the theories r^f phrenolo;.dsts. 'i he phrenologists busied themselves with findinr^ the brain ** seats " of the farulties recognized by tlif. jjsyrhrjjogisls, just as two centuries Ix^Tore a great i^rencli philosopher ha/1 found a seat for the s<^ju], in a little prrAulxrranx:e of the brain known as the pineal gland, lx:tween the cc*rebral hemis- j^heres. Gall, tlie famous founder of phrenology, did nr;t believe in the possibility of locating the ^ju\ itself, but he thrjught he could discover the seat of its various faculties. Of these faculties or aptitudes he recognized n/j less than twenty-seven. I ie hehl tliat each one was dependent upon the activity of a particular area of the cr^rtex, and fur- 2i8 MENTAL ORGANIZATION tlier, that the developineiit of each area of tlie cortex could be judged from tlie external shape of the skull/'^ Phrenolog)' has never met with scientific sanction. It very soon gave way to a theory which held that the brain functioned as a whole in the case of each specific mental act, aiid asserted, on the basis of numerous experiments in which portions of the brains of animals were removed, that there was no special seat for each of the mental functions. One part of the brain did not function in smelling, another in seeing, and yet another in willing; but the same parts, in fact, all parts, could in succession do all of these things. Removal of one part of the brain, it was claimed, instead of bringing about the loss of one particular ability or faculty, resulted in a general impair- ment of all mental functions. This doctrine that the whole brain was a single unitaiT organ of intelligence may be regarded as the physiological equivalent of the psyclio- logical theory of the unity of mind. The theory, however, that all parts of the brain had the same function finally gave way before the results of remarkable experiments performed during the latter part of the nineteenth century. These experiments called forth a doctrine of the specialization in function by different parts of the brain, kno\\ii as the doctrine of cortical localization. Localization of a particular mental process in any part of the brain means simply that the part in question must be active whenever tliat mental process occurs. It does not mean that other parts of the brain never cooperate with the centre in which a given ' *' L'anatomie et la physiologie du systcme nerveux ; en generalet du cerveau en particulier. avec des observations sur la possibilite de reconnaitre plnsiers dispositions intellectuelles et morales de I'homme et des animanx par la configuration de leur tete," 4 vols., Paris, 1810-1818. THEORIES OF BRAIN ACTION 219 function is said to be localized. Thus, to say that vision has its seat in the extreme rear of the cerebral cortex, in the occipital lobes, means no more than that whenever one sees, the brain cells in this region are active. Investigation has now localized all the senses in some part of the cortex. For example, the centre for vision has been discovered in the rearmost part of the cortex, in the occipital lobes, through experiments by Munk and others, which proved that removal of both occipital lobes in the monkey causes- complete blindness. Hearing has been definitely localized in the temporal lobes of the cor- tex, lying just within the temple, and the cutaneous and muscular senses, which give sensations from the skin and muscles, in a long convolution extending along the side of the brain. It has been found, moreover, that certain regions, situated just in front of the cortical seat of cuta- neous and muscular senses, could be stimulated by elec- tricity, so that particular muscles contracted. These regions have been named the " motor area." They are composed of the brain cells connected through nerves with the muscles; whereas the sensory areas — the seats of the various senses — are made up of the brain cells connected with the sense organs through sensory nerves. The sensory areas receive nervous currents from the sense organs, while the motor areas send nervous currents out to the muscles. In man, the sensory and motor areas do not include more than about one-third of the whole cortex. The general function of the remaining two-thirds is the coordination of incoming currents with outgoing ones. Such a state- ment of function is decidedly vague, of course, serving to do little other than conceal ignorance. The localization of sensory and motor areas in the cortex has been unquestionably established, an accom- 220 MENTAL ORGANIZATION . plishment that ranks high in modem science. Its inipU- cations, however, have frequently been exaggerated. Some writers have taken it to mean that each ditlerent mental process — a sensation, a memory, a judgment, or what not — involves exclusively a particular set of ners'C cells. This misinterpretation renders the theory of corti- cal localization a counteqxirt of psychological atomism. The Evidence from Correlations. — A brief account has now been given of three widely divergent views of the mind's mechanism. The first considers mind to be a combination of faculties, or manifestations of faculties; the second regards it as a homogeneous unit, or the mani- festation of a imitar)' soul ; the third Mieves it to be a mosaic of iimumerable elementary processes. The lirst is the multifocal theory; the second, the unifocal: and the third, the non-focal. Each has its cotinterpart in a theor>' of brain action. For the purpose of judging between the three, psycho- logists have carefully examined the correlations between different mental traits. Because each theorv' implies dif- ferent relationships between mental traits, the determina- tion of these relationships should establish one of the three as correct. The rapid multiplication of mental tests during recent years has been of great service in this con- nection. These tests measure innumerable traits. Just what relationship between the measurements of the^e traits is implied by eacli of the three news of mental organization? According to the multifocal theory, mental tests of the same general function or faculty should correlate more closely than tests of different faculties. Thus several different memor>' tests given to a large group of cliildren should correspond more closely with each other than EVIDENCE FROM CORRELATIONS 221 should a memory test with a test of sensory discrimination, reasoning, or attention. According to the second theory, the non-focal, no cor- relation at all should appear between any two tests except in so far as they involve identical elements. The fact that one child has a better memory for spoken numbers than another, would not, under this theory, indicate that he has also a better memory for printed numl>ers. There should, moreover, be no greater correlation betvvcn two different memory tests than between a memory test and a test of attention, because in all cases the correlation should l)e practically zero, if, as the non-focal theory states, all mental traits are unrelated. According to the third theory, the unifocal, the corre- lation between different tests is due entirely to some single general factor. Extreme versions of this theory require the correlations between all mental tests to be perfect. Since all mental traits are but manifestations of the working of a unitary mind, according to the unifocal theory, if one child's mind is better than that of another in any one specific trait, it should be correspondingly better in every other. The different theories of the mind's constitution thus imply different degrees of correspond- ence or correlation between the various mental traits; consequently, it is by the study of correlations that they must be compared. The correlations first obtained seemed to support the non-focal theory. They were so low in most cases as to suggest little or no correspondence between any two mental abilities. Thus, Wissler, who published the re- sults of the tests given for many years to the freshmen of Columbia University, came to the conclusion that al- though the markings of students in college classes corre- aaa MENTAL ORGANIZATION late with each other to a considerable vlei;ree, thev do not bear out the mental tests, nor do the mental tests show nuioh correlation uith each other.'' To a considerable e:xtent the correlations found at tirst \vere low Ixvause of inaccurate measurements and inadt\|uate statistical niethods.^^^ V^en from the tirst, however, the correlations obtained were far from Ix^ing as low as the non-focal theory' demandeii. With improve- ment in tests, in the nuuiner of pviuj^- them and in the statistical methods of c;ilciilating" the correlations, it has gradually Wcome establisluxi that even quite dissimilar tests may sliow a ver>- decided correlation. With a lan^e group of individuals, scytnc degree of corresiXMidence ap- pears Ixnween their ranking"s in otie test ajui in any other test. Plainly, memal abilities are related. At the same time, no two tests give results that correspond per- fectly: so that while mental abilities are related, they are partially independent. This state of att'airs evidently cannot Ix" s;itisfactorily explained by any one of the three theories of mental org-anization under discussion. Some more flexible theory is evidently rei]uired. which will take into account the complexity of the conditions detennining any panicular mental ability. Such a theory- has recently been proposevl by Spearman, and is now widely known tmder the name of the tw\>-factor theory. It is immensely itnportant, and must consequently tx^ exajuinet.! in detail. Certain modi- fications may then Ix^ suggested, which seem necessary to adapt the doctrine to all the facts Ixxtriiig upon it. 1- ■ ■ ■ ■ — ■ " •Wissler. "The Correlation of M:ental and Physical Tests.** Ps-ych.^l\7!ral /vA'it-jf. .U.^tooai/"/! Sui^t^i't'tents. vol. iil No. 6, uxm. " '^^ See Speamian. ** ' General Intellisrence ' Objectively Determined and ^feasured." Amcn^iin .K^urftal c>f Fsy.'h^^l.^ijy.xol. xv. pp. j-\:--^:5. SPEARMAN'S TWO-FACTOR THEORY 223 Spearman's Two- Factor Theory. — Spearman's theory amounts to a combination of the non- focal and unifocal theories, conceding, in a way, the truth of both. On the other hand. Spearman finds no validity whatever in the multifocal theory. His opinion is ''that a person's suc- cess in any intellectual performance may ]jt regarded as the joint product of two factors/' " The one is * specific aWlity ' for the performance in question, with all its particular features. The second is ' general ability.' " " While the range of the specific factor is exceerlingly narrow, that of the general factor is universal; and lx:tween these two there appears to be no intermediate." ^^ It should be observed that Spearman's theory is not a theory of the functions of the soul, but simply a state- ment concerning the conditions which determine the nature, and more especially the efficiency, of any mental act. It considers that these conditions manifest two degrees of generality. In the first place, there are certain conditions that have to do with the efficiency of one men- tal act but of no other. These are specific abilities. In addition, however, there is a general factor, which influences the efficiency of all mental acts. This is gen- eral ability. Neither specific ability nor general ability are mental processes; they are conditions of mental proc- esses, that is, factors determining the efficiency of mental processes. The success of a mental act never depends upon either specific or general ability alone, but always upon both. Spearman applies to mental phenomena a principle that is indubitably applicable to physical phenomena. For " Hart and Spearman, " Mental Tests of Dementia." Journal of 'Abnormal Psychology, vol. iv, 1914, pp. 219-221. 224 MENTAL ORGANIZATION example, let us consider the strength of tlie thumb and of the tliigh. Each is influenced by factors tliat cannot affect the other, such as the development of specific muscles. The muscles of the thumb may be impaired without in- jury to tliose of the thigh. At the same time the strength of both is influenced by a more general factor, one affect- ing the strength not only of these two parts of the body but of all regions — the condition of tlie blood. A man may have a strong thumb and at the same time be weak in the legs, but his strength in both regions must suffer from a fever. It is immediately apparent that all events and their characteristics are caused by conditions of varying extent and influence. The price of potatoes is affected by spe- cific factors, which have no effect upon prices of wheat or beans; but more general factors, such as war, join these specific factors in determining the price of potatoes and other commodities as well. The price of potatoes is not determined solely by war, the general factor, nor by the success with which potato bugs are exterminated, a specific abilities in the case of mental performances, he factors and others, acting simultaneously. Spearman's theory merely insists upon the existence of both general and specific factors; it does not explore the exact nature of these factors. Nevertheless he offers suggestions in detail, in order to clarify his theory. Of specific abilities in the case of mental performances, he gives the following illustration : " Suppose," he says, " that a schoolboy has surpassed his fellows in the observation of birds' nests. His victory has, no doubt, depended in part on his capacity for the general form of mental activity known as * observation.* But it has also depended on his being able to apply this SPEARMAN'S TWO-FACTOR THEORY 225 form of activity to the matter of birds' nests; had the question been of tarts in the pastry cook's window, the laurels might well have fallen to another boy. A fur- ther influence must have been exercised by the accompany- ing circumstances : to spy out nests as they lie concealed in foliage is not the same thing as to make observations concerning them in the open light of a natural history museum. Again, to discover nests at leisure is different from doing so under the severe speed limits prescribed by the risk of an interrupting gamekeeper. The boy's rank may even depend largely on the manner of estimating merit; marks may be given either for the gross number or for the rarity of the nests observed ; and he who most infallibly notes the obvious construction of the house- sparrow may not be the best at detecting the elusive hole of the kingfisher. Every one of these features of the observation, then — and their number might be indefinitely extended — must be considered as capable of influencing the success of our hypothetical boy; one and all constitute elements of the ' specific ability ' concerned. Any per- formance may have a large or small proportion of such elements in common with another performance ; in other words, the specific ability for the one may have much or little overlapping with that for the other." ^^ When specific elements so overlap that two perform- ances are almost identical, *' a person's success in one of them must give probability of success in the other also, and the two performances must become highly correlated with one another." When, however, two performances are so different that there is little or no overlapping of specific abilities, the correlation between them is due " Hart and Spearman, op. cit., pp. 219-220. 15 226 MENTAL ORGANIZATION entirely to the general factor, a factor \\hich intluences all performances. Although he is certain that a general mental factor exists. Spearman is doubtful of its exact nature. He refers to it as a common fund of intellective energy, and considers it closely connected with the capacity for vivid awareness or attention. Whatever the nature of the general factor, it contrasts sharply with mechanical habit. The highest correlations with intelligence are produced by performances requiring the most attention. ^^^ It is true that in the case of morons, the most mechanical tests, such as mere rate of tapping, show well-nigh as much correlation as tlie more intellectual — as the interpretation of pictures for instance.^"* Spearman explains this by the fact that at a level of ability as low as that of mentally defective children, not even the simplest tasks are thor- oughly enough mastered to Income mechanical. Having observed that mental ability is a matter of attention rather than of mere mechanical skill. Spearman proceeds to point out that one of the most remarkable dilYerences Ix'tween an attentive activity and a purely me- chanical activity is that the latter does not interfere with simultaneous activities. More than one non-mechanized activity, on the contrary, cannot be carried on at once with success. One's first efforts to ride a bicycle require atten- tion, and consequently they occupy the mind fully ; in time, however, the performance becomes practically mechanical, so that the rider is able to look freely about him, to pon- der over problems, or to light a cigarette. Now, if the attentive activities are thus distinguished from the mechanical by acute competition with one another, plainly "Burt. British Journal of Psychology, 1909, p. 167. "Abelson, British Journal of Psychology. 191 1, p. 300. SPEARMAN'S TWO-FACTOR THEORY 227 they are competing for something; if the perfection of a non-mechanized activity can occur only at the expense of all other activities, the conclusion is unavoidable that all these manifestations of energy are derived — to some extent, at least — from a general fund. Thus Spearman ajncludes that his general factor may very well Ixi the general funrl of brain energy possessed by the individual. The two-factor theory, although primarily psychologi- cal, has, like other theories of mental organization, its physiological counterpart. The specific elements of men- tality may be identified v^ith the efficiency of particular cortical regions or particular chains of nerve cells, whereas the general factor corresponds to the efficiency of the entire cortex. Spearman, with the great majority of contemporary psychologists and physiologists, believes it to be well established that " each momentary focus of cortical activity receives continual support from energy liberated by the entire cortex." Ihe matter is put very clearly by Pillsbury, in a recent textbook : " When we speak of the action of a single group of cells," he writes, '' it is probable that the group is merely the centre of excitation in a very wide region. The excitation that arouses that group spreads to very remote parts of the brain. Action is always of large masses of nerve-cells, but of the mass, certain portions are emphasized, the others acting in very much slighter degree. There is a complicated interplay of part and part throughout a very large portion of the mass of neurones, although only a relatively few are in great activity. . . . Each contributes its share to the total action, although one alone stands out prominently." ^-^ ""Essentials of Psychology," 1916, p. 43. 228 MENTAL ORGANIZATION I was similarly convinced concerning the functioning of the cortex by experiments showing the speed with which a person can move his lingers in response to the cessation of a light or a sound. ** The explanation of the experi- mental data," it was stated, ** seems to require us to regard the central nervous system as not merely a network of paths, but also as the seat of a comple:x system of inter- related activities and potential energies wJiicJi is disturbed tliroughout by any change in any part of the system." ^^ *' There is energy, the intimate nature of which we must admit is as yet unknown, present in tlie central nervous system. It is probable that this energy is of an electrical nature, and that it involves many, if not all, of tlic neur- ones of the central nervous system. The condition within any one neurone is to be thought of as interrelated with tlie condition of all tlie others, so that there is always involved an immensely complicated and widespread system of energies, including, perhaps, both potential cliemical energies and electrical activities." -^^ A disturbance occurring at any one point in the cortical system of energies brings about a readjustment of the whole, which readjustment may release energy on die motor side and produce bodily movement. Every mental operation, then, as Spearman points out, requires two tilings : *' First, a specific activity of a particular sys- tem of neural structures; and, secondly, the concurrence of neural energy from the whole, or a large part, of the cortex." ^' The present work does not permit discussion of all "Woodrow, "Reactions to the Cessation of Stimuli and Their Nervous Mechanism." Psychological Review, vol. xxii, 1915, p. 451. " Op. cit., p. 446. " Hart and Spearman, op. cit, p. 72. A MULTIFACTOR THEORY 229 the proofs presented by Spearman in support of his theory. Certainly they are impressive. In spite of the fact that his theory is still on trial/^ it probably comes closer to the truth than any theory of mental organization proposed to date. Its particular merit is its emphasis upon the ex- istence of general ability. Spearman hesitates to identify this general ability with general intelligence, Ijut in all likelihood his theory will eventually narrow to a theory of intelligence, a theory, that is, applying only to performances that are correlated with intelligence. A Multifactor Theory. — Notwithstanding its great value, Spearman's two-factor theory is undeniably in need of one fundamental alteration, as well as minor modifications. As I have said, it combines elements of the non- focal and unifocal theories, holding the conditions which determine the efficiency of any mental act to be al- ways one of two degrees of generality — either very spe- cific or very general. Now it is probably much nearer the truth to say that efficiency is determined by conditions of all degrees of generality than to limit these conditions to two degrees of generality. At any rate, the evidence at hand clearly shows that there are conditions intermediate in generality between the very specific and the very general. Does not an accurate view of the constitution of intel- ligence, then, coinbine all three theories of mental organi- zation, the unifocal, the multifocal and the non-focal? Such a theory regards the conditions of success in any act of intelligence as being of at least three degrees " See McCall, " Correlation of Some Psychological and Educa- tional Measurements." Teachers College, Columbia University, Con- tributions to Education, No. 79, 1916, pp. 56-59. Also King, " The Relationship of Abilities in Certain Mental Tests to Ability, as Esti- mated by Teachers." School and Society, vol. v, 191^, p. 209. 230 MENTAL ORGANIZATION of gcnemlity. namely, very geiienil. quasi-general and very specific. Just what the intennediato faculties are is a problem Avhose ejKperimental solution has only begun. Recent work indicates the existence of a general nieinory ability.'-'^ Although not certain that the general capacity for atten- tion is different from Spearman's general factor. 1 Ivlieve that I have demonstrated that there is a general capacity for attention>'^ There is evidence also of a general capac- ity for imagination.*- Thonulike. contradicting his earlier views, now refers to the mental '* levels " of sensitivity, association and analysis,-^ By ** levels " he means exactly what others mean by getieral capacities or faculties, namely, that two tests of the same function or level will correlate more closely than two tests of different mental functions or levels. To speak of a general memory ability, or faculty of memor}'. does not mean of course that this general ability is the only condition of successful rememlvring. There are in addition specific conditions which vary in the case of each different thing to be remetnbered. as well as the gener:il intelligence factor. Thus a good memor)' for faces mav accompany a bad one for names. Each act of memor}- involves certain factors which partially differ- entiate it from every other. Nevertheless. ditYerent mem- ory t^sts correlate with each other more than tests chosen ** Carey. " Factors in the Mental Processes of School Children," part ii. '* On the Nature of the Specific Mental Factors." British Jountiil of rs\L'hohH]\'. vol. viii. 1015. p. So. *^ '* The Faculty of Attention." /ournal of Exf>enm<'ntal Psy- chology, vol. i, ipiO. pp. JS5-31S. " Heymans and Brugmans. " hitelligenzpriifungen niit Studi- erenden." Zeitschrift fur angcuKvidtc Psychologic, vol. vii, 1913. pp. 317-331. ""Educational Psjxholog)'," revised edition. loio. pp. 190-191. A MULTIFACTOR THEORY 231 at random. Consequently it is correct to speak of a person's general memory ability. His memory may in general be good, although for some things it is much Ixitter than for others. The theory at which we finally arrive, then, as the only one suited to all the facts, may be termed a multif ac- tor theory, contending that the factors determining the nature of any mental event, like those determining any other event, l^long to many different degrees of general- ity. The cause of anything is the sum total of the con- ditions producing it; and these conditions always show an indefinite number of degrees of generality. For practi- cal purposes of the psychology of intelligence, the factors determining the efficiency of any particular performance may be classified, no doubt, under one of the three head- ings : specific, general and quasi-general. Factors of at least these three degrees of generality always cooperate. Our multi factor theory, then, at once combines the three old theories — the non- focal, the unifocal and the multi- focal — and endows each with a more elastic utility. CHAPTER XTT iii'Ui'Pi rv Definition of Hcrcdiiy and Knviianmcnt. — All c'w- cuinst.UK-cs whu-h ilotonuinc uh.it .i Inunan Ivini; is. or what lio shall Ivconio. tuav Ix^ i;Tou|H\l uuilor two head- in i;s : otwironniont and horoihty. I'.vcrv child orii^inates in the nnion ot two i^eiininal colls, the ovnni oi the teniale and the sperniato/oon c^t the male: conseqnently. all that he ever becomes de|>ends npon the orii;inal natnre of these two cells or else npon the intlnences \Yhich act npon them. .\ny trait that is dne to the natnre of the i;ermin.\l cells is the resnlt iW" hcrcvlity : while any trait dne to inthiences aciini; npon these cells as they develop into a man or wonum is canscvl by environment. .Vn individnal need not resemble either of his paretUs with respect to a s;iveti trait in order that we may con- sider tlun trait inherited, b'or example, a child tnay owe the color oi his bine eyes to hercvlity. and have brown- eved p.nents. Pmt the tr.m in ipiestion mnst Iv dne to the natnre of the i;erm cells contribnted by the parents. Similarly, any trait which is lackin^^- Ixvanse of the ak^ence of something;' in the i;enn cells, and not Ivcanse of any defect in the environmei\t. is lackini^' becanse of hercvhty. It is trne that the presence of any trait is never entirely canscvl by either heredity or environment, bnt always by K^tii. S.'ff.r environment, at least favorable etionj^h to maintain life, mnst always exist. The tuvessity of a suit- able environment is especially evident ii\ the case of mental HEREDITY AND ENVIRONMENT 233 traits, since few, if any, mental traits are present even at lliat relatively advanced stage of development marked hy birth. Hiit the nervous system is present at birth, and the nature f>f mental traits that later develop depends ui>on the nature and development of the nervous system. The nervous system in turn depends upon the original germ plasm as well as upon the action of environmental factors. Thus, indirectly, mental traits rruiy be clue to heredity, and it is quite conceiva];le that they are de- termined by heredity to the same extent as are many physical traits. In view of the intimate relation lx:tween heredity and environment, it seems at first impossible to determine whether the cause of any mental ability or disability lies in heredity or in. c*nvironment. It has lx*en established, iHjwever, in many cases, that certain mental defects could not have l>een avoided under any environmental condi- tions, and that certain mental abilities would have Ixien manifest in any ordinary or ** normal " environment. The meaning of " normal environment " must be kept in mind throughout a discussion oi the inheritance of mental traits. A normal environment signifies any that will allow an innate tendency to develop. For example, a child niay l>e formed from the union of germ cells of such nature that, given a certain c^nvironment, he will develop a high degree of musical ability. Musical ability here me^ms talent for Ixicoming a musician under proper training. Obviously, everyone has not this ability tr> any marked rlegrec. Now, it may \xt found that (;nly those children whose cnvironmcmt displays certain charac- teristics liave this j)otential musical skill. On the contrary, we may find that environments can vary enormously with- out affecting the capacity of children dwelling in them 234 HEREDITY to respond to a musical cdiicatioti. In that case, musical alvility ^vouUl l)c licrcclitary. At the same time, an abnor- mal environment would clearly hamper the development of mnsicxU ability. Partial starvation in early life, con- linement in a dungeon, or severe injuries to the brain would prove fatal to such development. Thus an ex- tremely abnormal environment could prevent the develop- ment of musical capacity, in spite of the stronj^est heredi- tary tendencies. To call any environment nonnal which is not extremely abnormal may seem too vague a conception, but it is necessarily inclusive. Hence, to tenn a capacity hereditary means that its development will dejKud upon heredity only providing environmental conditions are ** nonnal." Methods of Investigation. — The part played by hered- ity in the determination of an individuiil's mentality has been studied by two widely different statistical methods. C^ne of these makes constant use of coefficients of corre- lation, and may l>e termed the correlational or hiomctrical method: the other traces family histories, and may be called the pedigree method. The correlational method utilizes measurements of a certain trait for two memlxTs of the same family, say the father and the son, in a large numlxT of families. Two lists of measurements are thus secured, one for fathers, aud one for sons, the measurement for each son IxMug paired with that of his father. Then the coeflicient of correlation between these two lists is determined, and called the amount of correlation between father and sons with respect to the trait measured. This coethcient sIiowl-j to what extent the standing of the fathers agfrees with that i^f their sons. In a similar way correlations are calculated between brothers, or IxHween fathers and daughters, or grandparents and grandchildren. METHODS OF INVESTIGATION 235 The correlational method, unlike the pedigree method, does not trace out all the members of each generation. The correlational method gives the amount of resemblance existing on the average between persons related to each other in a s[>ociried manner; fcjr example, as father and son, or as brothers. The pedigree method, on the other hand, records what proportion of the offspring are like one or the other of their parents, for many successive generations. The correlational method may show that sons lack fifty per cent, of equalling their fathers exactly in height. The pedigree method, on the other hand, classi- fies fathers as tall, medium or short, and then gives the percentage of sons who fall in the same class as their fathers. The fundamental assumption of the correlational method is that the greater the influence of heredity the greater will Ije the resemblance l^etween relatives of any specified degree of relationship. It is noteworthy, how- ever, that even where heredity is undoubtedly the cause of a trait, the resemblance between relatives in that trait is far from perfect. In a trait as unquestionably deter- mined by heredity as color of the eyes, there may be in many particular cases no resemblance l^tween parent and offspring. Among the children of brown-eyed parents may be some with dark eyes and some with blue ; but the blue-eyed children owe the color of their eyes to heredity no less than do the brown-eyed. Children do not originate from the eyes, but from the germ-cells of their parents; and the color of children's eyes is determined not by the color of their parents' eyes but by the nature of their parents' germ-cells. Characteristics of a parent's body or mind are no sure indication of the characteristics of his germ cells. 236 HEREDITY Besides the difference between the germinal and the bodily traits of a parent, numerous considerations prevent a perfect resemblance between parents and offspring-, even in purely hereditary traits. If the two parents differ in any trait, as they are likely to do, then, in spite of heredity, the resemblance of the children to one or both of the parents must be imperfect. Again, some traits (or their absence) , may be caused either by heredity or environment. The cases in which a trait is caused by environment lowers the correlation of all cases taken together, and thus brings it about that the resulting coefficient of correlation conceals the fact that in many cases the trait is purely hereditary. For these and other reasons, heredity, when influential, merely causes persons of the same family to resemble each other more than persons who are not kin. In no case can it be expected to produce anything like a perfect resemblance, either between child and parent or between children of tlie same parents. Results of the Correlational Method. — Because corre- lations are always far from perfect, the results of the correlational method are somewhat inconclusive and diffi- cult of interpretation. ( The best way to arrive at an idea of tlie sigiiilicance of the correlations of mental traits is to compare them with the correlations of physical traits. Many physical traits, like the color of the hair and of the eyes, and the shape of the head, are certainly not affected to any great degree by environmental factors. The corre- lation between father and son in such physical traits is always nearly thirty per cent., and tliat between children of the same family about fifty per cent. Now if mentrJ traits prove to have the same correlation between parents and offspring as these physical traits, then parents and off- spring may be said to show the same resemblance in mental traits as they do in purely hereditary, physical traits. RESULTS OF CORRELATIONAL METHOD 237 As a matter of fact, the correlations for mental traits and for physical traits are substantially the same. Practically all the numerous investigations conducted lead to this conclusion, a conclusion of great practical importance, whatever its interpretation. One particularly interesting investigation is that by Karl Pearson,^ who obtained teachers' ratings for a num- ber of psychological traits in the case of one thousand pairs of sibhngs. (Siblings are children of the same parents; a pair of siblings consists of two brothers, two sisters, or of a brother and a sister.) The traits included were : Ability, vivacity, conscientiousness, popularity, tem- per, introspection or tendency to self -consciousness, asser- tiveness and handwriting. The teachers' ratings of these traits, made without the aid of any special tests, and on a scale distinguishing only a few different degrees of the trait rated, do not constitute very accurate measurements. Nevertheless, the ratings by three teachers, acting without consultation among themselves, showed fair agreement. By means of these ratings, Pearson secured a list of meas- urements for each trait, and for each measurement of one child he had a corresponding measurement of another child of the same parents. He was thus able to calculate the correlation between children of the same parents. The correlation was least in vivacity, greatest in ability and handwriting, but varied only from forty-three to fifty- six per cent., and averaged slightly over fifty per cent., which is practically the same as for physical traits. Another interesting investigation was made by Schuster and Elderton,^ who, to obtain data bearing on the inheritance of mental ability, made a study of the ^ " On the Inheritance of the Mental and Moral Characters in Man" Biom£trika, vol. iii, 1904, pp. 131-190. ^"The Inheritance of Ability." Eugenics Laboratory Memoirs, 1907. 238 HEREDITY class lists of Oxford College and of the schools of Harrow and Charterhouse. They noted the class standings of members of the same family, and then figured out the correlations. Expressing the resemblance between fathers and sons, a correlation coefficient of thirty per cent, was obtained, which agrees perfectly with the coefficients obtained in the case of physical traits. Other investigators have found similar correlations. Woods, in a well-known study,"' rated 671 members of European royal families on a scale of ten, basing his ratings upon statements of historians and biographers. He found a correlation of intellect and character between fathers and offspring amounting to thirty per cent. Earle ^ measured the spelling ability of one hundred and eighty pairs of siblings in one of the schools of New York City. Using carefully prepared tests, and grading each child by his deviation from the average for his grade and sex, he found a correlation of fifty per cent, between siblings. These investigations and others clearly demonstrate that mental characteristics or capacities run in families to just the same extent as do the color of the eyes or hair, or round-headedness and long-headedness. These physi- cal traits are unquestionably determined almost entirely by heredity. Consequently, mental traits run in families very much as though they were wholly determined by heredity. Nevertheless it is not safe to conclude that mental traits arc determined by heredity as much as physical traits. It must first be proved that the family ®" Mental and Moral Heredity in Royalty." 1906. * " The Inheritance of the Ability to Learn to Spell." Columhia Contributions to Philosophy, rsychofogy and Education, vol. ii, 1903, pp. 41-44. RESULTS OF CORRELATIONAL METHOD 239 resemblances were not produced by early home environ- ment, especially the influence of fathers and mothers dur- ing the early years of life. The task of unravelling the effects of environment from those of heredity has been attempted in various ways ; but it is a complex one, and so far has not been satisfactorily mastered. The evidence gathered, however, lends support to the belief that hered- ity rather than environment is the preponderating factor in the causation of individual differences in mental capacity. Certainly many of the factors that come first to mind in connection with environment are of very little conse- quence in determining individual differences. These are such things as bad housing, low wages, uncleanliness, unsanitary surroundings, unhealthy trade of the father, drinking and immoral behavior of parents, crowded rooms, condition of clothing, and so on. The effect of variations in such factors, which are everyday experi- ences — variations producible by political, economic or social control — ^has been measured. The correlations found between any one of these environmental factors and the mental traits of children is always very low, usually only three or four per cent. ; and Karl Pearson has shown that when the correlations for each of these more or less closely related environmental factors is as low* as this, the correlation for even a hundred of them taken together would still be so small as to indicate that their combined influence does not approach that of heredity.^ * " On Certain Errors with Regard to Multiple Correlation Occa- sionally Made by Those Who Have Not Adequately Studied This Subject." Biomctrika, vol. x, 1914, pp. 181-187. See also Elderton, " The Relative Strength of Nurture and Nature," Eugenics' Labora- tory Lecture Series, vol. iii, 1909, p. 40. 240 HEREDITY ThoriKllko/^ like Francis Galton/ attempted to solve the problem by studying twins, lie gave several mental tests to a considerable numl)er of twins, and found mem- bers of twin pairs to show much greater resemblance than do ordinary brothers and sisters. He points out that if the high resemblance of twins is " due to the fact that the two members of any twin pair are treated alike at home, have the same parental models, attend the same sch(>ol and are subject in general to closely similar environ- mental conditions, then twins should, up to the age of leaving home, grow more and nu^-e alike." ^ On the other hand, the nearer the resemblance of young twins comes to equalling that of older ones, the nuH'e must the resemblances l>e attributable to inlx)rn nature. Thorndike found the older twins to show no closer resemblance than the younger twins, and hence concluded that the influence (^f environtnent was slight. It should l>e pointed out, however, that Thonidike's data do not, unfortunately, extend to twins Ixiow the age of nine. It still remains piK^sible, therefore, that the great resemblance Ix^tween twins is due to the action of similar home environment, exerted at a very early and impressionable age. These studies of Pearson and Thorndike indicate that the only very important environmental factors in deter- mining individual differences are of two sorts.' The one is the direct psychological or educational influence of the parents during the vciy early years of life; the other is the mitritional and physical welfare of the brain during its early growth, Ix^th Ix^fore and after birth. Among the physical factors most likely to interfere with nutrition •"Measurements of Twnns." Archives of Philosophy, Psychol- ogy and Scirntifir }[t'thoiis. vol. i. No. i. ux>5. *" Inquiries Into Human Faculty." i8v^.^. pp. ji(>-J43. '"Educational Psychology," second edition, loio. p. <.x>. PEDIGREES OF FEEBLE-MINDED 241 of the brain are injury and disease affecting either the child or its mother. It is known that these fact(jrs are powerful enough in some cases to produce severe feeble- mindedness. Pedigrees of the Feeble-minded. — The case against environment as a cause of individual differences in chil- dren is made still stronger by the data concerning the causation of feeble-mindedness. Here the pedigree method has been the main reliance. This method has been employed on a large scale by certain of our institutions for feeble-minded children. These institutions, by the aid of field v^orkers, secure as complete a record as pos- sible of the ancestry of the feeble-minded children whom they receive. The field workers visit the homes of the children, in the country or in cities, interview the parents and relatives, family physicians, neighbors, judges and other informants. They note carefully the mental and physical condition of the parents, sometimes administer- ing mental tests, and secure facts about the ancestry of the child for as many generations as possible. These facts are charted in the form of family trees. Hundreds of these family histories have now been collected. The most extensive account of such studies so far published is that by Goddard, who secured fairly adequate data on the family histories of three hundred feeble- minded children. 'Upon analyzing the records he came to the conclusion that nearly eighty per cent, of these children owed their feeble-mindedness to heredity. The priority in causation of feeble-mindedness which Goddard ascribes to heredity is in agreement with the estimates of the overwhelming majority of qualified experts.^ Dr. Ashby, for example, in his testimony before the British • See Tredgold, " Mental Deficiency," 2d ed., 1916, p. 22. 242 HEREDITY Royal C^Miinilssiou on the b'cohlo-inindccl, stated that in at least sovcnty-iivc per cent, of tlie children he had examined, there was stroni;' prolxd>ility that the feeble- mindedness \\as heredit;iry, and that he had observed no si)eeial tendency for the development of feehle-niindcdness in the children of alcolu^lics, or of ^vonlen ^vho sulTer privation dnrini;- the period of i^estation. or in those chil- dren who live in nn favorable conditit^ns snbseqnent to birth. JMost oi the feeble-minded cases attribnted by Goddard to heredity had family histories showing- a lari;e nnniber of other cases of feeble-mindedrcss. In these cases, then, feeble-mindedness is inheritetl from feeble-mindedness : " in these cases, it is evident from the charts themselves that we are dealini;* with a condition of mind or brain which is transmitted as ret;-nlarly and snrely as color of hair or eyes." On the other hand, (uHldard, like ahncxst all oihcv antluM-ities, attribntes a. certain percentage of feeble-mindedness to nenn^pathic ancestry; that is, he regards it as hereditary, bnt as inherited, not fn^m feeble- minded ancestors^ bnt from ancestors who snlTered from snch things as insanity, paralysis, apoplexy and epilepsy.' 1 1 may be in these cases that the determining inheritance is merely a weakened constitntion of the brain which de- velops into feeble-mindedness as the resnlt of any of a long list of nntoward circmnstances snch as falls, severe sickness, brain disease, convnlsions or injnry at birth, or disease ov injnrv of the mother before the birth of the child.^^^ The analysis of Goddard's material brings ont fnrther interesting points. One is the resnlt of mating's in which IxMh parents are feeble-minded. Tt appears that in this '''See Trctlgold. (»/>. cit.. pp. 2S~2C\ PEDIGREES OF FEEBLE-MINDED 243 case, all the children, with rare exceptions, will be feel^lc- mindcd. Goddard's histories show 144 matings where both parents were feeble-minded. From these 144 mat- ings there sprung" 482 children who lived beyond infancy, and of whom information was obtainable. AUIjiit six of these 482 were feeble-minded. To Goddard^s cases in which both parents were feeble- minded, there could be added many more of the same sort. I have met with several of them, and in one case, besides visiting the entire family, obtained the intelligence quo- tients of seven of its members. The father of this family, when he works at all, collects ashes and garbage. The mother is too feeble-minded to manage the housework. The whole family is filthy and verminous. They live in a little, tumbled-down shack, on the outskirts of a small town. Members of a neighlxjring Lutheran church occas- ionally spend several days " cleaning house " for the family, but within a week things are as dirty as ever. There are eleven children, all feeble-minded. Three are old enough to work, but seldom do. The fourth child, Clara, aged 16 years and 8 months, quit school last Sep- tember, in the fifth grade. The remaining seven are all younger than Clara, and still in school. Their intelligence quotients, together with their school grades, are as follows :. i.q: 1st grade: Walter 69 2d grade : Jennie 74 4th grade : Alma 70 Sth grade : May 64 5th grade : Kate 78 6th grade : Maud 50 6th grade : Hannah 66 The first of these children to attract my attention was Maud. Maud entered school at the age of five years, and spent two years in each grade except the first. She has 244 HEREDITY been promoted, regardless of attainments, in accordance with the custom of promoting children who have been two years in a grade. She will never be promoted, beyond the sixth grade, however, for as soon as she is sixteen years old, she will be asked to stay at home. She is now 15 years and 3 months chronologically, and 7 years and 6 months mentally. The result of marriage between a feeble-minded per- son and a normal one is more problematic. According to Goddard, we must distinguish two kinds of normals : First, those who, normal themselves, have a feeble-minded parent or other ancestor, and are therefore capable of transmitting f eeble-mindedness ; and, second, those who are not only normal themselves but whose ancestry is entirely free from feeble-mindedness. Matings of feeble- minded persons with normals of tlie first sort, Goddard finds, cause one-half of the children to be feeble-minded. Matings of feeble-minded persons with normals of the second sort result in normal offspring, but the latter are all capable of transmitting feeble-mindedness to their chil- dren. ]\Iatings between such persons, normal themselves, but having a feeble-minded parent, result in the produc- tion, on an average, of three normal children to one feeble- minded child. Figures showing definite percentages like these, if cor- rect, prove clearly that there is a definite law of heredity which controls the transmission of feeble-mindedness. This law, whicli holds true of a vast number of animal and plant traits, as well as of a number of human traits, is known as Mendel's law.^^ Before it can be said to apply to the inlieritance of intelligence, however, we need very much more data than is yet at hand. " For an exposition of this law, see Mendelism, by R. C. Punnett. THE KALLIKAK FAMILY 245 The Kallikak Family. — Perhaps of all the family pedi- grees so far published none so strikingly proves the hereditary nature of feeble-mindedness as that which Goddard has published under the title, " The Kallikak Family." Our discussion of the heredity of feeble- mindedness would be very incomplete without a descrip- tion of this famous set of pedigrees. In tracing back the ancestry of a feeble-minded child called Detorah, the field workers arrived at the child's great-great-great- grandfather, called Martin Kallikak. Martin Kallikak, it was ascertained, was of fair intelligence, but when fifteen, owing to his father's death, was left without paternal guidance. "Just before attaining his majority, the young man joined one of the numerous military companies that were formed to protect the country at the beginning of the revolution. At one of the taverns frequented by the militia, he met a feeble-minded girl by whom he became the father of a feeble-minded son." ^^ This feeble- minded son, given his father's name, Martin Kallikak, handed the name of Kallikak down to posterity with the mentality of his feeble-minded mother. Martin, Sr., however, leaving the Revolutionary Army, married a respectable girl of good family, and through that union there originated another line of descendants of radically different character. Thus there are two lines of descendants, starting with Martin Kalli- kak, Sr., one of which arises from a mating with a feeble-minded woman, the other from lawful marriage with a normal woman. The comparison of these two lines of descent, traced " " The Kallikak Family," 1912, p. 18. 2 46 llKRKniTV through six g-encrations, is cxtromcly instnictive. The accoinpajwing duirt (Fig. i,0 shows the tirst generations. From the illegitimate son of Martin KaUikak have come 480 direct descendants. Delinite data has Ix^n secnred conceniing 1S7 of these, which prove conchisively that 14^^, or alxnit 75 per cent., are feeble-minded. It is not improlxible that the sc\n\e ratio would hold for the other cases concerning" which detinite data could not be Kvs'y 4:^ /HKv.' m (n) (n) ® (n) [n] (n) {N} a-H® fXKRia M/mM SUSM AMCfMEZ OUAtem JOSmt ABSf£ mftnuM MKOMZABnir 'ik ^ ti ^ 4 (b '^ (b (k (b A<:^-(>V AAT.tAV dl^SS Ci^SAi JSM..\i4 CUAXX^ ^.i^ AV>' Fig. 13. — Descendmits of Martin Kallikak, Sr., by his ^\^fe, and by a teoblo-mind«.\i girl. (Mvxlitiod fR"^m Goddard, '* The KaiUkak family," p. 37.) secured. In addition to feeble-mindedness. there was found a lil->eral admixture of illegitimacy, gross sexual inmiorality and dnmkenness. On the other hand, from the union of Martin Kallikak, Sr.. and his lawful w-ife, have come 496 direct descendants, ever}- one of whom is nonnal. *' In this family and its collateral branches, we find nothing but good representa- tive citizenship. There are doctors, lawyers, judges, edu- cators, traders, landholders, in short, respectable citizens, men and women prominent in ever}- phase of social life. INHERITANCE OF INTELLIGENCE 247 There have been no feeble-minded amon^ them ; no ille- gitimate ehildren, JKj immoral women." '■' The Inheritance of Superior Intelligence. — The Kalli- kak history, one of the most extensive and convincing yet published, is paralleled by many others. These histories show that there is no escape from the conclusion that feeble-mindedness is hereditary. But what about the (jther degrees of intelligence? The answer is that all the facts indicate that the higher degrees of intelligence follow the laws of heredity to just the same extent as do the lower degrees. Does not the Kallikak family itself present equal proof of the inheritance of *' normal- mindedness" and feeble-mindedness? Of course in this case the exact degree of intelligence to Ixi understood by *' normal '^ is not indicated. But there are other stud- ies which show that the highest degrees of intelligence, including genitis, are hereditary. Indeed, it is Francis Cjalton's study of Hereditary Genius that first really opened for investigation the subject of mental inheritance. And the record of feeble-mindedness seen in the degener- ate strain of the Kallikak family is no more remarkable than that of eminent ability displayed by the Edwards family. It is refreshing to turn from the inheritance of feeble-mindedness to studies of the inheritance of high grdered intelligence. / First, we may cite some statistical studies of Francis ■^'^Galton and of Woods. Galton chose for his study the 977 most eminent men out of a population of nearly 4,000,000. Each of these men, therefore, ranked as i man in 4000 for eminent intellectual gifts. These 977 eminent men, it was found, had a total of 535 relatives of a degree of eminence equal to their own. Galton then showed that " Op. cit, p. 30. fl48 HKRKPirV 077 avcrai^o inon have a ioi:\\ oi only 4 oininoni rolatives.' SiiKV ilio i^roup of 077 oniinont tnon had 5^^ 5 ciwincnt rola- tivos, as coinpaiwl with 4 tor a i^roup ot ilio s»uno nuiwlxM^ of ordiTiary inon. it appears that an oniinont man has on the avorai^o i^>4 litnos as many oniinont tvlativos as has the avorai^o man. Galton condudeii from his stndy that cminonoo doos not dopond npoti traitiing- or opportnnity bnt npon birth. 1 lo hold that tho possession of high S(.x'ia.l advantai^o doos not load to ominonoo nnloss acoompaniod by niarkod innato ability, and that tho man who is i^iftod with innato ability of a high ordor will Ix^ ablo to rise thn^ugh all tho obstaolos causod b\ inferior social ratik.^ (Walton's statistical thulings have Ivon continued by the rostilts of several other investigators. \\'oods. for exam- ple, whose stndy of heredity in Fnropean royalty has already boon mentioned, collected d.ata concerning the forty-six Americans who have statnos in the 1 lall of l-'ame. He finds that those celebrities have a great many more eminent relatives than has the averagv person; that they are. as he s;iys. " from tive hundred to one thonsand times as much related to distingiiishovl pov^ple as the ordiiuir)' mortal is." ^^ The Edwards Family. — It remains to till in these statistical generalizations with a bill of particulars. This we will do by a brief survey of tho F.d wards family, one of a numlxT of distinguishovl American families descrilvd by Davenport. \\'e cannot do Ixnter than to quote in full his description. Kisovl on gvnealogical manuscripts. " Fn.>m two Eng^lish parents, sire at least remotely descendeil from royalty, was Ix^m in ^fassiichusetts ** *' Heredity and the Hall of Fame." Pof^tthr Sci^rncf Monthh. lOT,^. pp. 445-5 5J. See also, Loewenfeld. "Ucber die Geniale Gijisitesthati^keit." iiX\>. THE I!:dwards family 249 Elizabeth Tutlle. vShc dcvcloiicd into a woman of great beauty, of tall and commanding apjjc^rance, striking car- riage, ' of strong will, extreme intellectual vigor, of men- tal grasp akin to rapacity, attracting not a few by magnetic traits, but repelling ' when she evinced an extraordinary deficiency of the moral sense. "'On November 19, 1667, she married Richard F.d wards, of Ilartford, Cr^nnecticut, a lawyer of high repute and great erudition. Like his wife he was very tall, and as they both walked the Hartford streets, their appearance invited the eyes and the admiration of all.' In 1691, Mr. Edwards was divorced from his wife on the ground of her adultery and other immoralities. The evil trait was in the blocKl, for one of her sisters murdered her own son, and a brother murdered his own sister. After his divorce Mr. Edwards remarrierl and had five sons and a daughter by Mary Talcott, a mediocre woman, average in talent and character and ordinary in appearance. * None of Mary Talcott' s progeny rose above mediocrity and their descendants gained no abiding reputation.' "Of EJizal>eth Tuttle and Richard Edwards the only son was Timothy Edwards, who graduated from Harvard College in 1691, gaining simultaneously the two degrees of bachekjr of arts and master of arts — a very exceptional feat. Lie was pastor of the church in East Windsor, Connecticut, for fifty-nine years. Of eleven children the only son was Jonathan Edwards, one of the world's great intellects, preeminent as a divine and theologian, president of Lrinceton Ojllege. Of the descendants of Jonathan Edwards much has Ixien written ; a brief cata- logue muit suffice: Jonathan Edwards, Jr., president of Union College; Timothy Dwight, president of Yale; Sereno Edwards Dwight, president of Hamilton College; 250 HEREDITY Theodore Dwight Woolsey, for twenty-five years presi- dent of Yale College; Sarali, wife of Tapping Reeve, founder of Litchfield Law School, herself no mean law- yer: Daniel Tyler, a general of the Civil War and founder of the iron industries of north Alabama; Timothy Dwight, the second, president of Yale University from 1886 to 1898; Theodore ^Villiam Dwight, founder and for thirty- three years warden of Columbia Law School ; * Henrietta Frances, wife of Eli Whitney, inventor of the cotton gin, who. burning tlie midnight oil by the side of her ingenious husband, helped him to his enduring fame; Merrill Edwards Gates, president of Amherst College ; Catherine Maria Sedg*wick, of graceful pen; Charles Sedg'wick ^linot, authority on biolog}' and embr}'ology in the Har- vard Medical School, and Winston Churchill, the author of Coniston.' These constitute a glorious galaxy of America's great educators, students and moral leaders of the Republic. " Two other of the descendants of Elizabeth Tuttle through her son Timothy have been purposely omitted from the foregoing catalogue, since they belong in a class by themselves, because they inherited also the defects of Elizabeth's cliaracter. These two were Pierrepont Edwards, w^ho is said to have been a tall, brilliant, acute jurist, eccentric and licentious; and Aaron Burr, Vice- President of the L^nited States, in whom flowered the good and the evil of Elizabeth Tuttle' s blood. Here the lack of control of the sex-impulse in the germ plasm of this wonderful woman has reappeared with imagination and otlier talents in certain of her descendants. " The remarkable qualities of Elizabeth Tuttle were in the germ plasm of her four daughters also : Abigail Stoughton, Elizabeth Deniing, Ann Richardson, and CONCLUSION 251 Mabel Bigelow. All of these have had distinguished descendants, of whom only a few can l>e mentioned here. Rol>ert Treat Paine, signer of the Declaration of Inde- pendence, descended from Abigail; the Fairbanks Brothers, manufacturers of scales and hardware at St. Johnsbury, Vt., and the Marchioness of Donegal were descended from EHzabeth Deming; from Mabel Bigelow came Morrison R. Waite, Chief Justice of the United States, and the law author, Melville M. Bigelow; from Ann Richardson proceeded Marvin Richardson Vincent, professor of Sacred Literature at Columbia University, the Marchioness of Apesteguia of Cuba, and Ulysses S. Grant and Grover Cleveland, presidents of the United States. Thus two presidents, the wife of a third and a vice-president trace back their origin to the germ plasm from which (in part) Elizabeth Tuttle was also derived, but of which, it must never be forgotten, she was not the author. Nevertheless, had Elizabeth Tuttle not been, this nation would not occupy the position in culture and learn- ing that it now does." Conclusion. — It is clear, from whatever angle the subject is studied, that heredityisan enormously important factor in determining a person's mental characteristics.^^ It is not altogether a simple matter, however, to decide upon the exact interpretation to give all the interesting facts that have been gathered. Perhaps the main point established is simply the fact of innate capacities. Since innate capacities are determined by the action of heredity, difference between children in innate capacities must always be due to heredity. But certainly one other point is established: that environments may be very diverse and still be equally suited to the manifestation of such innate capacities, or 252 HEREDITY the lack of them, as may exist. The environments of most children, especially those in the same community, in spite of great apparent diversity, are after all sufficiently alike, so. that differences in ability are almost entirely accounted for by differences in innate capacity, and not by differences in environment. \\'hen the environments of children are at all similar, we find that such dift'erences in environ- ment as may exist do not correlate with the degree of success of the children's perfonnances. The degree of success must consequently depend upon tlie innate poten- tialities of the children. Even though the capacities of an individual are not determined entirely by heredity, they might just as well be, so far as the public schools are concerned: for the only environmental factors of importance in the deter- mination of original capacities are those which act at a very early age — often at or before birtli, and during the lirst few months of life. Certainly, specific capacity, as the ability to learn to write the opposites of words or the ability to become a musician, and gcn-pe keep pace with their mental development, there is nothing to fear. But they certainly need to I'k? g-iven the opportun- ity to live and leani according to dieir quickened rate. They must not be held back to chafe under the restniint of their vitality and initiative, and must Ix' given tasks commensurate to their strength and aUHty to cover ground." ^'^ Dr. Gxxidard estimates that alvut four per cent, of the children in the public schools possess meiual ability so stiperior to the average child as to demand special oppor- ttmities in the way of special classes and courses of sttidy for their development.^^ Groszmann. who points otit that at present exceptionally bright childreji receive less atten- tion dian die feeble-minded and defective, though '* they are intinitely more wonh while." estimates that *' their number is at least equal to the number of abnonnals at the lowest end of the scale." ^- Provision for Dull and Superior Children. — The prob- lem of arranging for the special eviucation of exceptionally dull and exceptionally bright children is a ver>- compli- cated one. It should be \'iewed merely as part of tlie broader problem of adapting the school offerings as far as possible to the individual needs of all children, including *"The Exceptional Child.*" lOir. P- nr ""Two Tliousand Children Measured by the Binet Measuniv? Scale of Intelligence.*' PcdagOiiL-al S<'tmttar\\ vol. xviii. 1911, p. 236. " Ot. ciL, p. 139. DULL AND SUPERIOR CHILDREN 267 the mediocre, or normal. A school system, to make adequate provision tor individual d'fferences, must take into consideration the following three factors: (i) Unequal rates of progress made by children of different degrees of brightness; (2) uneven progress in different sul^>jc-ts; and (3) a high degree of individual attention to each pupil in each z. '. every class. Some very elaborate systems have Ix^n devised, many of which include parallel courses. Thus, the well-known plan evolved in Cambridge, Mass., separates the pupils at the beginning of the fourth year into a slow and a fast division. The pupils of the fast division enter upon a program which completes the remaining work of the grades in four additional years; those of the slow division follow a program which includes the same work, but which is planned so as to consume six years. Since the fast group does in two years the same work which the slow finishes in three years, the two groups at the middle of their parallel courses arrive at the .same point. It is then possible to reclassify the pupils. A pupil who has been in the fast group for two years may \)e transferred to the slow group and so finish in three more years, whereas a pupil who has been in the slow group for three years may be transferred to the bright group and finish with that group in two more years. A more elaborate arrangement of parallel courses is the Mannheim system, established in 1899, in Mannheim, Ger- many. Its most distinguishing feature, perhaps, is the provision of " furthering classes." These classes are com- posed of pupils unable to keep pace with the regular classes. They are of seven grades, corresponding to the first seven grades of the regular course, but differing in that the work done in them is much less extensive. The children 268 ORGANIZATION OF EDUCATION in tliese classes are not feeble-minded, they are simply dull, and include about ten per cent, of all the cliildren enrolled in the schools. The great majority of the chil- dren in these classes are never promoted to the normal classes, but simply to the next furthering class. The system permits, however, of the transfer of a child from any of the regular grades into one of these furthering classes, or, on the other hand, from one of the furthering classes to the regular grades. For the feeble-minded cliildren, there is provided a third course of study, the auxiliary school, which has only four grades. Besides the furdiering classes for the dull, and the auxiliary classes for the feeble-minded, the Mannheim system makes special provision for supeniomial children, comprising extra instruction in French for tlie sixth, seventh and eighth grades. After a preliminary course in French in the fifth grade, those pupils who have made good progress in this language and at die same time continued their good record in other subjects, and who are above criticism in matters of conduct and industry, are admitted to the regular foreign language classes. Pupils whose work in the foreign langaiage classes is poor are sent back to the regular classes. Whether or not such a complex process as the Mann- heim system is necessarv^, in order to adapt the means of education to the educability of the individual child, is a question. In small towns, at least, simpler methods will have to be devised. There is nothing superfluous, how- ever, in the accomplislunents of the ]\Iaiinheini system; and any system which does not solve all the problems there taken into consideration has very grave shortcomings. The aim should be to accomplish not only as much as the Mannheim svstem but more. Further progress is needed DULL AND SUPERIOR CHILDREN 269 particularly in the treatment of exceptionally bright chil- dren and in the matter of individual attention to all chil- dren, including- always — ^the mediocre. Many people believe that the best provision for bright children can be made, from the seventh grade on, by combining the sev- enth and eighth grades in one system with the four years of high school. Such an arrangement, besides possess- ing independent advantages, permits the exceptionally gifted children to pursue various subjects of a high-school grade in addition to the regular work of the seventh and eighth grades. Linking the regular high school work with the upper grades facilitates the provision of spe- cial opportunities for the brighter pupils of those grades, particularly as the work of high schools, with its instruc- tion by subjects instead of by grades, is itself usually organized upon a much more flexible basis than is that of the grades. When it is feasible to keep the classes small, a fairly simple organization will suffice. Holmes suggests the following as satisfactory : " The work would be based on what might be called a course of study in the fundamentals : this work would be so graded as to be within the powers of all normal children, both quick and slow. To it would be added a course of optional topics to be studied by the abler pupils largely by themselves, in order to develop initiative and self -direction. . . . " Beginning, perhaps, at the sixth grade, the work would be somewhat differentiated without in the least breaking up the class organization." As a chief feature, this plan requires a " supervisor of Individual work." " This teacher would be in charge of the work of four or six rooms. In her hands would be 2 70 ORGANIZATION OF EDUCATION the school ^velfare of all tlie individual pupils in these four or six rooms, but she would care especially for the abler pupils and also for the slow and backward. When an abler pupil had been promoted, of course she would sef that he Avas adjusted to the work of the new grade." ^^ As a rule, instead of one teacher to manage the education of both the brightest and dullest children, it is highly advisable to provide a separate teacher and room for each class of children. The Problem of the Feeble-minded. — In most of our large cities, the outstanding feature of the provision for exceptional children is the auxiliary class, often called an ungraded class. In some schools there is simply one of these classes for all the different school grades; in other schools, the auxilian' classes themselves are graded, and correspond to the first fotir regular grades. The pupils in these imgraded classes are chiefly feeble-minded chil- dren, ustially of the moron grade. Occasionally, how- ever, one meets with a child of the imbecile grade, and, on the other hand, there may be numerous borderline cases or children who are merely backward. These auxiliar\' classes tisually contain from ten to fifteen children, who ditTer* greatly in size and age, and W'ho are likely to impress the visitor as a motley group, even in those schools which have several grades, so that the children may be classified by mental age. The school- room contains, instead of the usual desks, tables and chairs of various sizes, which, at times, may be pushed aside to clear the floor for games. Arotind the sides of the room are work-benches, cupboards and store-cases, for dishes, tools, and variotis teaching materials. Sometimes ^^ Holmes. *' School Organization and the Individual Child." 1912, pp. 84-86. PROBLEM OP FEEBLE-MINDED 271 there is an additional room with a full kitchen and dining- room equipment. Where several of these classes are in the same building, there may be special rooms for manual training, for gymnastic exercises, for sewing, for cooking, and so forth. Sometimes one room is so equipped that it may be turned to any use that the instruction in hand makes desirable. ^^ Communities possessing these ungraded classes usually miscomprehend their function. The idea is wide- spread that the business of these classes is to enable children, by means of miracles, to '' catch up " with pupils in the regular grades. As a matter of fact, the great majority of the children in the ungraded classes, indeed, all who are properly there, can never be brought up to normal. Fortunately, this is now quite well under- stood by those in charge of these classes, if not by the community at large. The establishment of these ungraded classes for the feeble-minded in the public schools by no means solves the problem of subnormal children. In connection with every school system having classes for feeble-minded children, there should be, in addition, classes for dull children above the grade of feeble-minded. Under various designations, such classes now exist in a number of our leading cities, in addition to the classes for the feeble- minded. In them are included not only dull children but also backward children, who for one reason or another are simply delayed in their mental development. The public school ungraded classes for feeble-minded not only fail to solve the problem of the dull and backward children, but in a very serious degree fail to solve the " For further description, see Goddard, " School Training of De- fective Children," 1915, pp. 19-27. 272 ORGANIZATION OF EDUCATION great problem with which they are particularly concerned, that of feeble-mindedness. The auxiliary teachers do all that can be reasonably expected. The trouble is that the children of these classes do not go to school all their lives. The benefit received by the school training is lost and sometimes worse than lost in their subsequent careers. Some years ago a report was published giving the after- history of fifty persons selected at random from former pupils of ungraded schools of New York.^^ The findings were summarized in the statement that *' the majority are utterly incapable." Only two of the fifty were found " to show signs of being able to hold permanent employ- ment." In spite of the fact that these cases were all under twenty years of age, it was evident that in numerous instances the temptation to an immoral or even criminal life could not be resisted. Several of the girls, although feeble-minded, were engaged to be married; others had already found their way into some sort of " House of Refuge " or penal institution. The careers of the grad- uates of auxiliary classes show that in a large percentage of cases their training has failed to enable them to become independent and useful members of the community. The proper solution of the great problem of die feeble- minded remains to be determined. There are numerous proposals. Some authorities are convinced that we must increase the number of our state and city institutions for the feeble-minded until there are accommodations for the whole feeble-minded population. This would mean that the existing facilities w^ould have to be many times increased, for only a small fraction of the feeble- minded persons in the country, certainly not over a fifth, "Anne Moore, "The Feeble-Minded in New York," 191 1, pp. 45-49. PROBLEM OF FEEBLE-MINDED 273 are now in institutions. Such additional provision, of course, would necessarily be coupled with a law giving to these institutions the right to retain in their custody all inmates likely to become sources of trouble to the com- munity or to reproduce their kind. Another proposal advocates the permanent custody of all feeble-minded persons except those who, by means of a surgical operation, have been rendered incapable of reproduction. With such provision, one or two genera- tions would certainly behold great improvement. The problem would then be fairly simple. Of course new cases of feeble-mindedness would constantly develop. Not all f eeble-mindedness is hereditary. It must originate before it can be inherited, and it will continue to originate in the future from the same causes as in the past. And it would always be impossible to relegate to institutions large num- bers of the great mass of border-line cases. Certainly, though, the number could be so reduced that the burden would be comparatively light. Were there institutions enough for the great majority of existing cases, the num- ber would more than suffice for future generations. For the present, we must admit that the idea of putting all feeble-minded children under the control of institu- tions, unless they are sterilized, is an idle dream. The public has not yet been educated to the point of taking the drastic measures that are necessary to cope properly with the problem. Consequently, the immediately urgent thing, pending such education of the public, is to provide more thoroughly than at present for the after-care of the pupils who leave the ungraded classes of the public schools. In France, a Committee of Patrons is appointed in connection with every auxiliary school. Women must form a part of the membership. Some such committee 2 74 ORGANIZATION OF EDUCATION sluniKl exist in this country tor c\orv ungraded class. Its duty would Ix" to tuul oniployn\oiit suitable to the cajvacities and character oi persons coniint;- uutler its jurisdiction. A cominittee. however, no matter lunv charitably inclined, cannot Iv expected to act with the constant attenticni nea.\ssary iov the after-care of the feeble-minded; and its authority would Ix} limited. It would therefore seem desirable in addition to appinnt. under the law, on salary anil full time, especially qualilled otVicers, to look after the feeble-minded jXM'sons of the commimity. Such otVicers cmild Ik^ discharged u[hm lax performance of duty. If the feeble-minded are io mini;ie freely in society, we must, in adilition to givitig more attention to after- care, take jxiins to detennine exactly who are the feeble- minded memlxTs of a comnumity. and to enforce strictly the laws against their marriage. This rapiires the admin- istering of group intelligence tests to the entire school population, and individual examination oi doubtful cases. Thus, in the course of time, a list may Ik" secured of all feeble-minded persons and their addresses. The after- care otVicers or committees, and those having authority to grant marriage licenses, should be fin-nished this list. At present there is no way of enforcing the laws agTiinst the marriage of the feeble-minded, Kvause. with the exception of low grade cases, who are nc>t likely to niarr)-, the feeble-minded are not detinitely known. In Minne- sota, at the instigation of Dr. Kuhlmann. there is now Iving conductetl a census of an entire county — a rather populous one. 1 have no doubt that when the importance oi this work is publicly recognized, it will be extended to inchule the whole state. We must know who and where the feeble-minded are before we can care for them. CHAPTER XIV EDUCATIONAL METHODS After orj^anizin^ classes to adapt education to indi- vidual differences in brightness, it Ixicomes necessary to consider the pro[>er educational methods for use with different classes and different individuals within these classes. We must analyze the processes of which education consists anrl determine h(jw they vary with fli ff erences in mental ability. We are not infrequently told that the principles of education are the same for a dull f>r feeble- minded child as for a normal or bright one. But what are these principles? Many of them are stated in pul>- lished accounts of the education of the feeble-minded, but it is very doubtful whether any of them, as lairl down, arc a})plicable to the education of children displaying the higher degrees of Ijrightness. The search for principles must \)C continued ; and we may well Ixigin it by an an- alysis of the methods that have for over a century been evolving for the erlucation of the feeble-minded. The Savage of the Aveyron. — Attempts to provide an education arlapterl to the needs of feeble-minderl children gfj back to the sensational experiment marie by Itard at the beginning of the last century on an idiot of eleven or twelve years of age, known as the " Savage of the Aveyron." First discovered Ijy hunters, during the eighth year of the French Republic, in a wood in the department of Aveyron, France, entirely naked, and seek- ing his nourishment from nuts and roots, he led the life of a savage. He was unclean, made spasmodic and con- 275 276 EDUCATIONAL METHODS vulsive movements, showed no gratitude to those who aided him, attempted to bite and scratch those who coerced him, was able to make only a few animal-like sounds, and seemed altogether incapable of attention. Not only was he utterly wanting in the ability to speak, but even his gestures and bodily movements showed no trace of expression. He passed rapidly, and without apparent motive, from spells of pathetic sadness to violent out- bursts of laughter. His sole manifestation of intelli- gence concerned the satisfaction of his gluttonous appe- tite ; yet he lacked sufficient mental acumen to climb upon a chair in order to obtain food placed beyond his imme- diate reach. Contrary to the opinion of Pinel, the great pioneer in the study of mental disorders, who held that the case was one of rank idiocy, Itard believed the boy was merely uncivilized, and possessed an intelligence simply untouched by any sort of education. Had he regarded the boy as an idiot, las one without intellig^ence, he would never have undertaken his training, for he viewed his labors as an experiment in the philosophy of mind, designed " to solve the metaphysical prob- lem of determining what might be the degree of intelligence and the nature of the ideas in a lad, who, deprived from birth of all education, should have lived entirely separated from individuals of his kind." ^ For years Itard worked with utmost patience. He was con- stantly devising new and ingenious methods for awaken- ing the senses of his pupil, for developing a power of speech, and for getting the boy to exercise his mind in ^ Itard, " Rapports et memoires sur le sauvage de I'Aveyron, I'idiotie et la surdi-mutite," 1894, p. 9. This work is a collection of reprints, which includes Itard's paper of 1801 on the early develop- ment of the " Young Savage of the Aveyron." THE PHYSIOLOGICAL METHOD 277 the satisfaction of wants. At the end of five years of daily experimentation, Itard came to feel, as Segiiin puts it, that " there were other impediments besides savageness in his pupil;" and in a report to the Minister of the Interior he confessed that his experience had been not so much one of progress of the pupil as of failure of the instructor. Notwithstanding this modesty, Itard recog- nized that the personality of his ward at the end of five years' training offered a sharp and wonderfully favorable contrast with its original condition. The improvement was summed up under three head- ings : First, there was a marked development of the senses ; second, knowledge of language was acquired to such an extent that the boy could name objects, designate their qualities and uses, express his desires, understand orders, and, in the words of Itard, carry on " a free and continual exchange of ideas; " third, in spite of a persistent desire to enjoy the freedom of the fields and a marked indiffer- ence to the pleasure of society, there finally developed a sense of human relationship, manifested by signs of affection, by pleasure at having done well and by shame at bad conduct.^ How were these wonderful results accomplished? In general, by what has been called the physiological method, an elaborate series of ingenious procedures, later perfected and systematized by Scguin and described by him in great detail.^ The Physiological Method. — Seguin in 1837 founded the first school devoted primarily to the education of ^ Itard, op. cit., pp. 105-106. ^ " Traitement moral, hygiene et education des idiots," Paris, 1846. Also, " Idiocy, Its Diagnosis and Treatment by the Physiologi- cal Method," Albany, N. Y., 1864. Reprint published by Teachers College, Columbia University, 1907. 278 EDUCATIONAL METHODS idiots, and was instrumental in founding some of the most famous of such institutions in America. His account of the physiological method was based upon a lifetime of practical experience in the education of idiots, and a bet- ter idea of its principles may be obtained from his exposi- tion than from that of Itard, or, indeed, from any of his followers, for his work has never been surpassed. The fundamental principle of the physiological method is more easily stated than understood. It is based on the concept that an individual, although a unitary machine, has a number of interrelated faculties or '' functions." Each sense is one of these functions, and so also are the capacities for motion and speech. Dependent upon the proper development of these functions are others, not systematically enumerated, such as memory, association, attention and reasoning ability. The fundamental prin- ciple is therefore that education should train the various functions or faculties by means of drill exercises. This operation contrasts with an education which aims merely at imparting information or knowledge.^ Each function or faculty, each system of neurones, is developed to the fullest possible extent. Montessori illuminates the method by her reference to experimental psychology. Her procedure, in prin- ciple like that of Seguin, she says is based on that of experimental psychology.^ She considers experi- mental psychology to be a science wYiich tests or meas- ures the various senses and other functions. These tests involve sensory discrimination. For example, the experimental psychologist tests hearing by determining the * Seguin, " Idiocy and Its Treatment," 1907, p. 28. ' Montessori, " The Montessori Method," third edition, 1912, p. 167. THE PHYSIOLOGICAL METHOD 279 smallest perceptible difference between two tones, in loud- ness or in pitch; color vision, by the smallest perceptible difference in the hue of two colors; and touch, by the smallest distance between two points applied to the skin which will permit of their recognition as two instead of one. Now Montessori's idea is simply that whenever a function is tested, it is exercised, and so by simply using tests suited to children, tests which interest instead of wearying them, the educator may turn the psychologist's measurements into exercises for the development of the senses. Every psychologist knows that any mental test can easily be transformed into a game, and that if he is willing to sacrifice the idea of measurement, the variety of games is considerable. For instance, instead of asking his subjects which of two tones is the louder, or the higher in pitch, familiar objects, differing in sound when dropped upon a table or shaken in a box, may be used, and the child asked to guess which object he has heard. Moreover, psychological tests can be classified according, to the various mental functions which they test. Thus the physiological method is a number of more or less scien- tific exercises for the development of various functions or faculties. The training of the senses and of motor ability has greatest prominence in the physiological method. None of the senses is ignored, not even that of smell or taste. They are trained mainly by acts of sensory discrimination or comparison. The sense of sight is trained by practice in the sorting of colors, such as sorting a box of variously colored pegs into piles each of one color. Similar sort- ing exercises may be for length, form or size, in place of color, or, instead of simply putting together those which are alike, the child may be trained to fit the pegs 28o EDUCATIONAL METHODS into peg boards or form boards. These exercises, par- ticularly when the child is blindfolded, exercise the sense of touch. The sense of touch is further developed by having the child draw his fingers lightly over surfaces of various degrees of roughness with his eyes shut, until he is able to make fine distinctions. The sense of hearing is trained by identifying objects according to the sound they make, or by attempting to find on the piano a tone just sounded by the teacher. Great emphasis is laid also upon the use of music, not merely as a training for the ear, but as an aid to physical exercises, such as drill and dancing, and as a general stimulus to mental activity.^ Motor training, training in movement and action, is given by such exercises as cutting, folding, modelling, weaving and the use of tools. Imitation of the teacher's movements may also be used. At an earlier stage, it may be necessary to give training in elementary motor-coordi- nations, like those involved in standing and walking, and carrying objects. *' Consequently," writes Tredgold, " the first exercises must be directed towards teaching the child to maintain a proper balance of the body, to run and to walk, to push and pull, to seize, to hold, and to let go, tolerably large objects. For this purpose such exer- cises as mounting a ladder placed against a wall, walking between the rungs of a ladder placed flat upon the ground, marching in, out, and over various obstacles to the accom- paniment of music, and accurately covering with the feet a series of footprints chalked upon the ground, as recommended by Seguin, are of the highest service." '^ Catching and throwing a bean bag, picking up and * For further details, see Anderson, " Education of Defectives in the Public Schools," 1917, p. 104. ^ " Mental Deficiency," 2d ed., 1916, p. 414. THE PHYSIOLOGICAL METHOD 2bl carrying objects and innumerable other exercises are widely employed. In theory, the physiological method does not stop with the training of sensory and motor faculties, but usually it represents little else. However, even Seguin describes methods for the cultivation of memory and imagination and the moral sense, and some modern writers have listed exercises for the development of all the better recog- nized functions. Miss Morgan, for example, gives exer- cises, patterned somewhat after the psychologist's mental tests, for each of the following faculties : Sensation, per- ception, abstraction, association, attention, memory, imagination, invention, judgment and reasoning.^ These exercises are devised for a class of children somewhat above the grade of feeble-minded, including both the dull and the backward. For the light it throws upon the idea of training functions rather than the imparting of knowledge, and consequently upon the main principles underlying the so-called physiological method as described by its exponents, it is worth while to note some of Morgan's methods. Automatic memory is trained by having the child make ^' lists of common things, like the furniture in the kitchen at home, or all the things one cooks with, or all the things he has in his desk at school, or, if he goes to a carpentry class, all the tools he uses." " Another way to train automatic memory is to have the child repeat a series of words, numbers, or nonsense syllables which the teacher says to him, gradually increasing the number." Voluntary memory is trained by the writing of original rhymes. As the child learns his own rhymes by heart, he memorizes others on similar subjects. Gradually the * Morgan, "The Backward Child," 1914. 3S-- EDUCATIONAL METHODS coiniuirting" to mcniory ot prose iuid verso may supple- nient the verse writing. Exercises for the iinvigiiuitiou inchide retelling: stories, illustrating; stories bv trechaiul drawing, and making up stories accotnjxinying colored pictures. Invention is trauied by picture puzzles involving the piecing together of fragments and by cv^nipletion tests, like those descrilxxl in a previous chapter, in which the niissing words of a stopk^ must Ix" suppUcvl. These methods of so-calle\l physiological education arc brilliantly summarizevl by Biuet ** under the heading ot '' Mentiil Orthoj>edics.'* The name is suggestive. As physical orthojHxlics corrects the jxx^ition of a spinal verte- bra which is out of place, so meiUal onhopcvlics corrects, cuhivates and strenglhens attention, memory, perception, iudginent and will. By this art one seeks not to impart knowledge of facts and ideas to the children, but to develop their mental faculties.^^^ Rinet cites numerous exercises, some tx^rroweil fn^Jin Segnin. He follows Segiiin's prac- tict^ of reijuiring at intervals absolute quiet and immo- bihty; he introduces tests of strength of grip and speei.1 of tapping, in which the children are eticouragxxi to riv;vl each other: and he develops nioti^r control by having the childrett carr\' cups of water from one table to an- other without spilling a drop. An exercise of attention and memory, which he cmphasiL'cs particularly, employs a ver\' brief exposure of a large card on which a mimlx'r of objects are represented. The pupil must try to grasp in his attention all the objects on the card, and then write their names from memory-. A long series of such cards was carefully worked out. with a gradually increas- ing numlx^r of objects. This exercise closely corresponds * ' Les idces modemes sur les eiifants," I909» PP- i4o-i6i. "0/». cit„ p. 15a CRITICAL ESTIMATE 283 to what the psychologist calls a test of the span of atten- tion. JJinet states that subnormal children trained on this test were able, with a five seconds' exposure, to note and hold in mind as many as nine objects, long enough to return to their seats and write out the names — a performance of which many a normal adult would |je incapable. Critical Estimate of the Physiological Method. — I have now described in sufficient detail the method of education termed physiological or orthopedic. 1 have tried to make clear that the main principle, in the accounts of those who have done most to perfect this method, is that education should deal with the training of men- tal functions. It clearly implies the existence of mental faculties or powers, and aims directly at the training of these powers. Whatever the explanation, education based on this principle of formal exercise of fundamental functions has been successful. Its excellence is shown by results with feeble-minded children, from the time of Itard down to the present. Morgan, who discusses serenely the train- ing in backward children of attention, of voluntary mem- ory, and so forth, says that she gathered her material from an experimental clinic conducted for two years in New York City, in which children were tested for, and trained in, the particular deficiency revealed in them by examination. The brilliant results obtained by Montes- sori are known to all the world. Binet did not content himself with the testimony of teachers, but verified their reports of success with subnormal children by carefully devised mental and educational tests.^^ Binet became so enthusiastic as to believe that the method which formed " " Les idees modernes sur les enfants," 1909, pp. 144-146. 284 EDUCATIONAL METHODS the basis of the orthopedic method, so successful with the feeble-minded, was tlie proper one to use with normal children; he even went so far as to declare it to be the only method of genuine education. ^'^ The success of the method must be admitted; but it is exceedingly doubtful whether its success is due to the fact that the exercises it employs are aimed directly at the development of the various mental faculties, as faculties, rather than at the imparting of particular bits of knowl- edge or special arts. It is likely that the authors of the method have misunderstood tlie reasons for its success. Let us consider, for example, some of Montessori's state- ments. She writes that *' In a pedagogical method which is experimental the education of the senses must undoubt- edly assume the greatest importance." This education of the senses, she says further, '' makes men observers, and not only accomplishes the general work of adaptation to the present epoch of civilization, but also prepares them directly for practical life." These remarks are unsupported by any known facts. So far from being fundamental, keenness of the senses, as a previous chap- ter points out, plays a relatively unimportant part now in the determination of intelligent behavior. The corre- lations with intelligence shown by sensory keenness — that is, the ability to make fine sensory discriminations — are low. The correlation for tactual discrimination is practically zero, and for weight discrimination appears to be negative. No test of sensory discrimination has ever been demonstrated to give a correlation of over .50. Moreover, it should be understood that Montessori's methods have succeeded only with young children. No doubt, among the large assortment of general rules stated " op. cit, p. 154. CRITICAL ESTIMATE 285 in Montessori's book, may be found some capable of use in the education of children at any age; but the body and substance of the Montessori method is the training of children toween the ages of three and seven, the kinder- garten ages. Now during these ages, it is true that train- ing in sensory discrimination should occupy a very import- ant place. It should do so, I would suggest, simply 1>ecause at these early ages, the sensory capacities have reached a relatively advanced stage of growth. A child is not so far behind a man in sensory discrimination as in the ability to concentrate attention or to reason. In short, in devoting attention to the education of the senses of a young child, we are training him in the occupations for which, at the time, he is best equipped. The crucial explanation of the success of the so-called physiological or experimental method, then, is not the fact that it trains the mental and physiological functions, but that it is adapted to the capacities possessed by the child — that it exercises the innately strong capacities. From this point of view it is easy to understand the suc- cess with which Seguin's methods have met in the edu- cation of the feeble-minded. These children, like the normal children trained by Montessori, were for the most part between the mental ages of three and seven. At these ages, the sensory capacitieshavecompletedsuflficient grov/th to be profitably trained. The capacity to make movements is also well developed. It is sensory training and motor training, consequently, that loom largest in education dur- ing the mental ages three to seven. Besides these, there is some training in memory work, particularly in rote mem- orizing. The memorizing capacity is usually good enough to justify more attention to its exercise than is custom- arily given. There is a prejudice against rote memory 286 EDUCATIONAL METHODS training, because it is so much less useful than training in judgment and reasoning. But feeble-minded and young normal children have little capacity for judgment and rea- soning. Their most valuable asset is rote memory capac- ity. Its training should, therefore, form a conspicuous part in their education. Experiments in the Education of Children with Exceptional Abilities. — It begins to be clear that the study of methods successful with backward and feeble-minded children may shed light upon the general problem of relat- ing individual differences in intelligence to educational methods. The same principles apply to the education of exceptionally bright children as to that of the exceptionally dull; but these principles must be properly understood. The most important is that the methods employed must be suited to the child's capacities. These capacities are by no means* the same in the bright child as in the dull or backward child. Methods which would be ridiculous when used with the latter may bring about brilliant results with the former, ^ome illustrations of carefully recorded cases will make this clear. The education of a little girl who, at the age of twenty-six months, could read from any primer fluently, and with better expression than most first-grade children, has recently been described in detail by her father.^ ^ While the intelligence quotient of this youthful prodigy is not given, nor that of one of her brothers, it is stated that her oldest brother, aged eleven, has an intelligence quotient of 1.7, the highest quotient which Terman, who communicates the case, has ever discovered among Cali- fornia children. As one studies the methods which pro- 13 << 'An Experiment in Infant Education." Journal of Applied Psychology, Vol. II, 1918, pp. 219-228. EXCEPTIONAL ABILITIES 287 duced such wonderful results, one cannot help but realize that their success must have been due to aptitudes very exceptional in a child of such an early age. Among the capacities unusually advanced in growth were the in- stinct of curiosity, the powers of memory and attention, and the desire for approbation. The following method, used to teach the capital letters, clearly indicates interests far stronger than in the average child. " I placed in her hands a book," writes her father, ** which, in addition to a number of pictures interesting to the child mind, contained capital letters in flaring type and colors. She at once became interested in the pictures and fell into the habit of rushing to me whenever I entered the house, to have me show them to her. At these times I took her on my lap, turned to a picture, told her what the objects represented were, and chatted about them in such fashion as seemed most to arouse her interest. Occasion- ally I turned suddenly to the pages of capital letters, pointed to one of them, and exclaimed with feigned excitement, * Oh, Martha! Look! Look! There's P!' Then, without giving her time to discover the deceit and to determine for herself that after all there is nothing wildly exciting about the letter P, I returned to the pic- tures and excited her interest in the vicissitudes of Tom the Piper's son, only to turn back after a few moments and point with an exclamation to another letter. The pictures were unquestionably of great interest to her, and as the references to the uninteresting capitals were only occasional and momentary, the net result of these sessions was that she found the book as a whole a great joy, failed to discover the camouflage in the matter of the letters, and nevertheless became familiar with them. When she 28S EDUCATIONAL METHODS was nineteen months and thirteen days old she was able to recognize an.d prononnce all of the capital letters/' l^ven, more interesting- is the method nsed in teaching the small letters. " I drew the letters carefnlly on the Ixack of Inisiness cards, and kept a few of these in my pockets. When she grew tired of looking at pictures T allowed her to play with these cards, of course calling her attention from time to time to the letter on the back of each. She became interested about this time in explor- ing my coat pockets and pulling the contents out of them, so I sometimes i)laced a few cards in a pocket open to attack, and allc)weil her to puU them out one at a time, refusing to let her have a card until she pronounced the letter on the one already pulled out. As this refusal constituted an obstacle to an interesting investigation, she sensibly surnunuUed it by observing the letters and pronouncing them in order to experience the joy of delv- ing into the depths of the pocket for a new card. At (^ther times I varied the play by sitting down with a pack of the cards in my hand and giving them to her one at a time to be carried by her across the room and delivered to her number or aunt, refusing to give her another until she told mother or aunt the name of the letter on each card delivered. Both mother and aunt always displayed a highly gratifying interest and astonishment at all infor- mation so volunteered by her, and she doubtless felt that she was playing a very important role in an extremely important matter. At any rate she enjoyed the process immensely and incidentally learned her small letters." The al>ove methods, it is tnie, are simply ingenious applications of the fundamental principle of all teaching, which is to link the thing which the child is to leani with activities in which he is already interested and which he EXCEPTIONAL ABILITIES 289 naturally enjoyvS. The wonderful success of these methods, however, can be explained only on the postulate of very exceptional capacities on the part of the child, and the whole experiment is merely an illustration of what special methods may accomplish when directed towards the training of special capacities. Exceptional mental attainments cannot be produced by any educational methods unless exceptional al>ility of some sort exists in the child. On the other hand, wlicn. superior abilities are present, no formal methods need to be used. The main thing necessary is to provide oppor- tunity for the child to exercise these abilities freely and spontaneously. The child needs to be studied and intelli- gently guided, but will learn naturally and without fixed lessons or tedious drill. This naturalness of learning when unusual talent is given plenty of opportunity for its exercise is strikingly illustrated in the development of Winifred Sackville Stoner, Jr. The following extracts are taken from an account of her education written by her mother, when the child was twelve years old. "Winifred has no set lessons, but from early train- ing she has become such a lover of good literature that she would be most unhappy if deprived for a single day of converse with her book companions. She reads at least for an hour each day. At present she is reading every- thing she can find alxDUt Japan, .as she plans to write a play on this subject. For two hours she helps me as my secretary, answering letters, and working on * The Natural Educational Manual ' and ' Natural Educational Game Book,' two lx>oks to be ready in fall. Winifred and I will be joint authors of these books, and another lx)ok belonging solely to the kiddie, and which she calls ' Facts in Jingles/ will be published by Bobbs-Merrill TOO EDUCATIONAL MKTUODS in :i tow ^Yeeks. Winifred has corrected proof of this U>ok since retnrnini;* troni New York. ** She practices tor ^x^rhaps an hcnu* each day on IxMh her vioUn and piano, and anuises herself phiyinj;- for hitle colorevl chiklren \vho hve in cabins facini^- onr reser- vation, pkiying" for them on the mandohn. jew'sdiarp. or orchestra IxMls, *' One or two afternoons of each week she i^oes io the Ivach to swim, and on Wednesday e\enini;- she is aUowtxl lo attend a httle dancini^chibnntil 0.30 r.M. •* Nearly every pleasant Satnrday alternL^on she i;"oes with several friends of her ai;e canoeini;" ov Ivtaiiizing. As you know. North Carolina is the home of some very interesting" plants, among- them the \'enns tly-trap. bladder- wort, pitcher-plant, and other caniivorons n\emlxTs of the plant family. Winifred is intensely interested in these plants, and has sent sjxvimens to a nnmlxM* of our friends in northern cities, ** Each moniing she plays at least one gume of tennis Ix^fore breakfast, and after dinner in the evening she and I play croi]uet or take long walks through the white s:tndy tracts aroimd our home. ** At least tifteen minutes is spent in the kitchen each day gaining knowledge of culinax)- matters, and yesterday Winifred made a skirt for herself. '* On one oi our up-stairs [xirches I have a regtilar gymnasium. :uid here every afternoon, when we are at home, we exercise for at least one half hour before taking a shower- txith and rub-down. " The little girl has learned how to drive an autv^- niobile, and occasionally 1 let her drive wlien we take motor-trips. She drives :Uso her horse Coujxmi. :uid oc- casionallv rides horseback. . . . EXCEPTIONAL ABILITIES 291 "Winifred has a canary which she has tamed and taught to do many wonderful tricks, and while she writes her stories on the typewriter he sits on the carriage of the machine and sings to her. To-morrow she is to receive a monkey and poll-parrot from a sea-captain, and then you will believe that there will be no time for study of bcjoks, as the pets will take up every spare moment. *' 1 am writing to you of these trivial matters s^j as to paint a picture of the simple, happy, full life Winifred leads at this chrysalis time of life, when no child must Ixi forced to study or to play." ^* Winifred Stoner at six months could talk ; at eighteen months, read; and at five years, speak eight languages. She has specialized in music, art and eurhythmic dancing. She is said to be a perfect specimen of physical health and strength, and to be altogether free from conceit. There are a numlx;r of types of supernormal chil- dren. Some are merely precocious, that is, growing at an exceptionally rapid rate; when grown up, they may not Ije especially intelligent, but they mature early. Others, who may grow either fast or slowly, have a really superior mental endowment. This superiority may be quite general, and apply to the great bulk of their mental faculties. In other cases, while the general level of the mental capacities may 1^ above normal, only one or a very ties. One capacity may be very superior, while the others course no child is equally developed in all of his capaci- ties. One capacity may be very superior while the others may be only slightly so, or even mediocre. The superior capacities of exceptional children of this latter type may l^>e easily overlooked by the teacher. Indeed, it is fre- quently alleged that some of the great men of history, "Groszmann, "The Exceptional Child," 1917, Pp. 108-111. 293 EDUCATIONAL METHODS Avho did poorly in school ^vork, ^vere meii of one-sidei.i development, whose \-aluable traits \vere not appreciateii by their scliool teachers, but were given opportunity for their development outside of school. The education of children who show only a one-sided exceptional capacity should take its cue from tlieir special- ties. Naturally we should desire to prevent a one-sided development, and to produce a child of well-balanced character and intellect. This c^mot be done, however, by ignoring- the child's special aptitude and attempting to educate him along lines unrelated to his specialty. I f we tr}- this, we shall simply find him a stupid child. It is necessar}- to make use of the special talejit, to use it and the interests related to it as a starting point, as a Ixise from which to conduct our entire educational campaign, extending into all the fields of learning. A ver}' good illustration of supernonnal ability, in Avhich one trait in particular stood out above all others, is afforded by one of the boys trained in the laboratory school of the National Association for the Study and Edtication of Exceptional Children in Plainfield. New Jersey. This boy, thirteen years of age, was of a decid- edly inquisitive type, and possessed to a high degree initiative and the tendency to original experimentation. This highly desirable side of his character was in danger of being suppressed by his teachers because coupled with mischievous tendencies. He " built fires in the cellar of his home, not from viciousness, btit because he wanted to see what would happen. He played innumerable pranks on his schoolmates and teachers, who did not imderstand him. so that he was constantly in mischief and upset all discipline." Taken into the laboratory- school, however, '* his inquisitive tendency was made use EXCEPTIONAL ABILITIES 293 of through experimental studies of all kinds, in the science laboratory, in the workshop, in road and building con- struction and in many other ways. He was given oppor- tunity to apply his great energy in numerous outdoor games and sports, playing Indian, building wigwams, camp-fires, etc. His book-studies were carefully coordi- nated with this life activity." ^^ The effect of this treat- ment was to change his entire mental and emotional atti- tude, and after leaving the laboratory school, he was reported as standing at the head of his classes in select private schools. Sometimes a high order of intelligence is accompanied by defects which make it imperative to base education upon the use of the stronger faculties. A striking instance is described in detail by Bronner. " We know," she writes, "of a boy now 14 years old whose entire school career has undoubtedly been greatly modified for the better because his intelligent parents understood bet- ter than his teachers the harm that was resulting from the use of methods not adapted to his defective functioning in certain mental processes. It was early recognized that the boy had poor auditory powers and exceptionally good visual powers. When five years old he drew a very good representation of the fagade of an ancient university building he had seen, and at seven made a most complicated drawing of a quadruple expansion waterworks engine. Though a great effort was made from the time he was a year old or so to teach him Mother-Goose rhymes and other couplets, he never recited correctly the simplest verse until he was six years old; nor has he ever been able to carry a tune correctly or sing a song, in spite of intensive and oft-repeated attempts "Groszmann, op. cit., p. 121. 294 EDUCATIONAL METHODS to teach hini simple iiuisic. It is interesting to note, for instance, that * America ' has Ixvn snng- atul played to him hnndreds of times and even played by him without his acquiring the ability to sing it. *' At live years of age this lx\v was sent to a fnie private school where the teaching in the first grades was largely oral. When in the third grade he wus placed in a sub- class for kickward children Kx^ause he was so retarded in number work. Though the Lx^y made no progress in music nor in memorizing verses, this was not inter- preted as of any sii^niit'icance, nor was any elYort made to utilize his good visual powers in place of his defective powers of audition. When, however, his parents were told (by an unusually competent teacher) that the Ix^y was not leaniing arithmetic aud was prolxably defective in this t>'pe of work, they themselves began to teach him by visual presentations. In two weeks he had not only mastered the work assigiied the grade, but led his class. In the next two years, acquiring the power to leani by visualization, he accomplished the ordinary work of four school grades. . . . His powers of perceiving logi- cal relationships are extremely good, and these, together with his quite unusual visual gifts, enable him to maintain class standings considerably in advance of his years." ^® The preceding concrete examples suggest several prac- tical conclusions. One important point is that we must make a more systematic elYort to discover unusual gifts or unusual abilities about which to focus a training that w\\\ lead to the most useful development. Educational efforts must be devoted to bringing out at each period of his life the best there is in the child. In this connection "**The Psychology' of Special Abilities and Disabilities." 1917, pp. 2s:si-224. EXCEPTIONAL ABILITIES 395 I have been greatly interested in the very successful experiment being carried on in a large school system in a neighboring city, with children of superior brightness. By means of intelligence tests, those children are selected whose mental ages indicate that they ought to be doing more advanced school work. These children are then given further mental examinations and individual study by a special teacher, who aims to discover their leading aptitudes and interests, to create more favorable mental attitudes on the part of the children towards their work and their teachers, and finally to prepare them for a trial in the higher grades which accord with their advanced mental ages. I am informed that the great majority of these children are now doing better work in the grades to which they have been advanced than in the grades in which they were originally discovered. A word of caution must be added. I have said that a more systematic effort should be made to discover special abilities and special interests — in both dull and superior children — and that the training given children should afford opportunity for the development of these exceptional capacities. This does not mean, however, that we should determine in which one of his mental faculties a child is strongest, and then devise formal exercises for the development of this faculty to the exclusion of the rest. The ideal is to train all his really valuable capacities so that they may obtain their greatest usefulness. The development of intellect and character must be as many- sided as is consistent with a proper balance between time, energy and cost on the one hand and the results that are likely to be achieved on the other. But whatever capacity we are trying to train or whatever art or knowledge we are trying to impart, we shall succeed best by beginning 296 EDUCATIONAL METHODS where the child is strong and working out gradually into regions where he is weak, by organizing our endeavors as much as possible into a related system in which the funda- mental appeal is to the child's natural aptitudes. Only in this way can we get out of the child his greatest effort, the limit of hard work and drudgery of Avhich he is capable, and the development of a strong character. The Training of Mental Capacities. — It remains to consider what it means to train a capacity. In general, it may be said that training cannot increase the funda- mental capacities, but simply teaches the cliild to make the best use of such capacities as he possesses. This training may consist in the formation of very general habits, such as habits of concentration of attention and the most efficient methods of study, or it may consist in specific information, such as the multiplication table. In teaching the child the more general habits, formal exercises may be used. These formal exercises, like tlie exercises for training the senses, which are so prominent in the physio- logical method, often seem to be aimeH at the develop- ment of faculties as such. In reality, however, they con- sist simply in drill for the formation of habits which are useful in a very wide range of situations. To train a cliild's capacities, then, does not mean to give him more memory, Diorc attention, or viore reasoning power, but rather to lead him to memorize that which is most useful, to attend to those things which are most w^orth while, and to reason out problems of ever-increasing weight. Let us consider somewhat more in detail the training of a mental capacity — for instance, the capacity for atten- tion. Capacity for attention, like that of intelligence, is determined mainly by heredity, environment before the age of school, and by growth, As a general power of TRAINING OF MENTAL CAPACITIES 297 the mind, a general capacity or faculty, it is as little sub- ject to increase by education or to improvement by train- ing as is general intelligence.^^ Therefore, all that train- ing of attention really means is that, by a change in the conditions under which attention is given, and by a reduc- tion, through habit and familiarity, of obstacles to its application, there may be brought about, in many direc- tions, a greater ease of mental concentration. Before any change can be made in the conditions affecting attention, one must ascertain the nature of these conditions. There is, in the first place, a considerable variety of objects w^hich secure the attention even when that capacity is very feeble indeed. Among these are loud sounds and bright lights, strong odors and severe pressure on the skin — in short, all very intense stimuli. The great attention value of intense stimuli is enhanced by the factors of suddenness or novelty and of movement or rapid changes of any sort. Sometimes, too, a stimulus which is not strong enough to attract attention upon its first occurrence will do so by dint of repetition. Atten- tion to such stimuli represents the earliest stage, known as passive or spontaneous attention, and is said to be due to the " objective " conditions of attention. In addition to things which provoke notice through the objective conditions, there are others which arouse interest because of their relation to instinctive tenden- cies. The most fundamental instinct is that of self-preser- vation. It is partly on account of this instinct that intense, sudden and changing stimuli have such a strong appeal. They are often dangerous. But even when the object is not intrinsically of the sort to attract attention, " Woodrow, " The Measurement of Attention." Psychological Monographs, 1914, No. 76, p. 141. 298 EDUCATIONAL METHODS it ^vill do so if it is iittcil to bring- out some instinctive tendency — for example, that of self-presenation. That this tendency is recognized and accepted as an important factor in attention is seen in its application, by the ingeni- ous primary teacher, to reading lessons. The teacher draws on the blacklx^ard a picture of a house, and fills the interior space with common words, each of which represents one of the children in her class. She then tells the children that someone has set fire to the building and that only those can be saved whose naiiies are read. When a child reads a word it is erased and thus in imag- ination they rescue themselves from the tliuiies. So inter- ested do the children become in preserving their ** lives/' that they learn unfamiliar words with renewed interest and increased attention. Again, an object which may satisfy hunger will attract the attention even of an idiot. Thus tlie savage of the Aveyron, though insensible to the loud- est noises — he seemed not to notice a pistol shot — could nevertheless hear the fall of a nut ! There are many other instincts than that of self- preservation which promote attention to the objects with which they are concerned. It is impossible to give a complete list of them, because their expression is so indefi- nite and so quickly modified by learning. Among the more obvious ones are fear, anger, love and affection, sociability and sympathy, desire for approbation, rivalry, lighting, loyalty, imitation, all the numerous forms of play and gaming, curiosity, collecting and constructive tendencies, hunting and roaming, and the regulative instincts of morality and religion. ^^ In general, when- ever an interest is shown naturally by many children, we "See Kirkpatrick, "Fundamentals of Child Study," 1917, chap- ters iv-xiii. TRAINING OF MENTAL CAPACITIES 299 may be sure that it is a tendency at basis instinctive, that is, one which does not need to be learned, but occurs spon- taneously on account of the inherited disposition of the nervous system. Each instinct involves an action, or general line of conduct, of a sort to satisfy some want or need. It is a response made to some stimulus, some ob- ject or situation which attracts attention in a powerful manner without any effort on the part of the subject. The appeal to the child's attention exerted by the primary or original excitants of an instinct is rapidly extended to everything in any way associated with these originally interesting objects, as well as to all the means for suc- cessfully carrying out the instinctive activities. Spontaneous attention, caused by the sheer intensity, or force, of the external stimuli which excite the senses, and instinctive attention, brought alx)ut by the direct appeal to instincts, are hardly above the animal level. In all normal persons there develops from these a higher attention, embracing matters only indirectly connected with the satisfaction of wants. This sort of attention is called out when the child meets with some obstacle to the immediate carrying out of an instinctive response. A problem which at first protrudes itself upon his atten- tion because of its instinctive interest for him, later acquires a new and higher interest through the mere fact that it has already attracted attention. For it is a funda- mental law that a certain familiarity with an object or situation, knowledge about it or past experience with it makes it interesting and easy to attend to. Thus new inter- ests are derived from instinctive interests, which in turn develop still others, until we finally reach the highest stage, that of sustained attention to abstract problems. There is no more fascinating nor valuable study for 30O EDUCATIONAL METHODS the teacher than that of development in her pupils of one interest upon the basis of another. She may obser\-e, for example, that at first the instinctive desire of appro- bation from his teacher, as wcW as fear of her, may lead a child to follow directions. In doing so, he meets \vith difficulties which hold his attention simply because the teacher is over him. but whicli. provided the tasks imposed are closely related to instinctive activities, may in time become interesting of themselves. Through working w^ith arithmetic problems bearing ujK>n the construction of kites, or upon the playing of store, the child may acquire an interest in arithmetic for itself, independent both of its connection with his pastimes and of his desire to please his teacher. Having acquired an interest in arithmetic problems, he may, in turn acquire an interest in the higher branches of mathematics, partly because in them he meets with items ^^'ith which he is already familiar, and partly because he needs these higher branches in solving the arithmetical problem in which he has now become interested. The preceding hasty sketch of the various types of conditions which call out attention should suggest an understanding of what is involved in the training of at- tention. This, as I have stated, does not mean increasing the fundamental power, but merely directing its appli- cation to the loftiest and most profitable topics. In children of the lowest level of brightness, the idiots, even the power of spontaneous and instinctive attention is very feeble. Many instincts are lacking, the only one approaching dependability being the instinct to satisfy hunger. Children witli attention of tliis sort have to l>e trained, like animals, through reward by food. Even food, however, will not hold their attention for any length TRAINING OF MENTAL CAPACITIES 301 oi time; for at each distraction their attention is (Hverted from its original object and does not return. All that can Ixi accomplished with these children is to teach them to feed themselves and to keep themselves clean; their /)ower of attention is not great enough for the accom- j^lishment of more complicated tasks. In the higher degrees of feeble-mi ndedness and in dull children, the power of attention has greater strength. It cannot be trained, however, for long occupation with non-instinctive activities. It is hopeless to expect these children ever to devote themselves assiduously to book learning or to abstract ideas. Their education must be primarily through play and games and limited to those crjncrete activities — responses to real objects rather than ])rinted symbols — in which the instincts naturally and with little modification manifest themselves. Even under these favorable conditions, short periods of exertion, say of half an hour or an hour, must be followed by a rest. Play, it is true, is a great educational factor in the life of any child, whatever his age or brightness. Games and playful occupations suited to children of every age exist in great numlxT, and much care has been expended in developing their educational possibilities. Entire courses of education by means of play-schools have Ixtcn worked out and put into successful operation. It is with children of the lower mcnital ages, however, that the use of play and games is particularly indispensa?jle. Their feeble attentions require constantly the support of the interest accompanying pleasurable activity. In addition to definite games, there are innumerable playful activities which have especially great educational value. Among these may be mentioned the following: Collections (minerals, stamps, coins) ; cooking, particu- 302 EDUCATIONAL METHODS larly for girls; drawing; field work (study of butterflies, birds, fishes, flowers and ferns) ; flower and vegetable gardening; mechanics, such as the making and sailing of boats, putting together various kinds of machinery and making toys; dancing and dramatics; music (singing, orchestra and piano); photography; sloyd (basketry, cardboard and paper work and wood work) ; and print- ing.^ ^ Of all these activities perhaps none has such a Avide appeal as dramatics. The dramatic instinct, whether expressing itself in the playing of Indian or Eskimo or in the production of a Shakesperian tragedy, is a force, which, if given opportunity for its development, is of invaluable help in the teaching of language, of manners, of decoration and mechanical construction and of sewing and costuming, and lastly, in the implanting of noble and influential thoughts which will inspire and elevate throughout a life-time. With young normal children and with dull or feeble- minded children of any age, it is imperative to make a careful forecast of the maximal attainments of attention, and then to plan out a method of linking these attain- ments as closely as possible with the most free and natural expression of the child's instincts. At every stage, it should be made certain that there exists a strong appeal to a natural tendency to action on the part of the child, for otherwise he cannot be expected to persist in his efforts to the neglect of the slightest distraction. With these children, the difference between a wise educational method and a foolish one is that the former endeavors " For details concerning the educational use of these activities, see Johnson, "Education by Plays and Games," 1907, pp. 51-64. See also Hetherington, "The Demonstration Play School of 1913," University of California Publications^ Education, Vol. V, No. 2. TRAINING OF MENTAL CAPACITIES 303 to lead the child's attention to simple, useful occupations instead of attempting to direct it upon book learning. With normal children, the ordinary school subjects, which have been selected through generations of experi- ence, offer excellent training of attention. They provide topics of interest, of a gradually increasing complexity, and as items of information, possess a degree of import- ance difficult of exaggeration. The main need here is a more careful consideration of individual interests. The most effective leading of attention can be secured only by utilization of individual tendencies and interests, whether instinctive or acquired. The thing upon which it is desired to have the child concentrate must be connected with his individual interests — not simply with those of children as an abstract class of beings. In the words of McMurry, " Each study must be intimately related to the pupil — to each pupil, just as far as possible. It is expected to appeal to his ambition and establish purposes within him; to give him practice in judging the relative values of facts as they bear on these purposes, which would be impossible if he sensed little value in the projects or purposes themselves ; to lead him likewise to organize data, use knowledge frequently, and do all these things largely on his own initiative and in an independent way.*' ^^ To thus vitalize a study for the pupil and at the same time to connect it with the life of society in general, McMurry reminds us of the value of live, interesting questions. " The idea is that a study is ideally a sum of live questions, alive both to the adult and to the child ; and that a good course of study in any branch of knowl- *"The Uniform Curriculum With Uniform Examinations." Journal of Proceedings and Addresses of the National Education Association, 1913, p. 135. 304 EDUCATIONAL METHODS edge is a sum of such problems along one great line of interest, organized in good sequence and containing data enough to furnish satisfactory answers to the problems." The setting of interesting questions is certainly one of the most fundamental ways of securing attention. As one high authority writes in a discussion of how to secure attention, '* Man is blind to what does not correspond to his momentary purpose." The purpose may be aroused, this authority continues, by a question asked by another, or by some task that has been set, or problem that has been raised.^^ McMurry gives the following questions as illustrations of questions which are both interesting to the pupil and related to social life : ^^ In Physiology and Hygiene: What are the uses of food in the body? How keep the digestive organs in health? How care for the teeth ? How take care of the nervous system? In Arithmetic, in the early primary grades: How read the street numbers, and house numbers about us? How use money for travel on street cars? What quantities of milk and cream are commonly bought ? Make out bills for given amounts. How keep score for the game of bean bag, dominoes, etc. ? Make out such scores. In History: What has been our treatment of the Indians ; and what seems to be our plan in regard to them in the future? On what occasions has the union of our states been threatened; and is it now permanently established? "^Pillsbury, "The Fundamentals of Psychology," 1916, p. 254. ^ Op. cit., pp. 135-136. TRAINING OF MENTAL CAPACITIES 305 In exceptionally bright children, one may confidently expect that, long before its growth is completed, the capacity for attention will become sufficiently powerful for sustained study of difficult subjects. The natural curiosity and ambition of such children lead them of their own initiative to undertake tasks to which the attention of normal children can scarcely be held by all the artifices of the expert teacher. Such children — often neglecting the humdrum routine of their regular classes — follow out elaborate courses of study in foreign history, in litera- ture, in mechanical construction and in the scientific study of plants and animals and of rocks. With these children, then, above all others, pains should be taken to encourage the use of initiative — that great quality upon which de- pends true leadership, research and discovery, and conse^ quently the progress of humanity at large. Especial care should be taken, also, to develop the sense of duty and of responsibility to others. One of the most crying needs of society to-day is that the possessors of superior intellects should enlist in public service instead of engaging solely in their own selfish advancement. Not only in superior children, but in all children, to incul- cate a sense of the individual's duty to society, to impart those ideals and habits which characterize the desirable citizen, should be a fundamental aim of education. But this development of the social sense is particularly import- ant in the exceptionally bright child. He is the one who, when grown up, will have by far the greatest surplus of ability beyond the needs of his own support, the one who will be best able to serve society; and yet, just be- cause of the ease of his success, he is the one in whom the sense of duty and responsibility is least likely to be developed by the ordinary school curriculum. 3o6 EDUCATIONAL METHODS That the appeal of social service is capable of exercis- ing a powerful influence on children of superior ability is vividly illustrated by an instance that came to my notice while carrying on an investigation in one of the Minnea- polis public school classes. There was one boy in this class v^ho had been advanced from the preceding grade l^ecause of a superior intelligence quotient. He had done only average Avork in his old grade, and when promoted, promptly settled down to the same mediocre position in the more advanced grade. One day, after recess, this boy came in and found the children who sat in the same row of desks as he did complaining to the teacher be- cause their row didn't get more of the stars given as rew^ards. The teacher turned to the boy as he came in, and said, '' Do you know what they are saying about you?" When he replied with surprise in the negative, the teacher explained that the other children were blam- ing him, claiming they didn't get the stars because he wouldn't work. The other children joined in a chorus, '* It's all your fault." The boy turned perfectly wdiite; it was clear that he was strongly affected. Before this time, he had not wanted to succeed; but henceforth he felt that he was working for the group and not for himself ; and under this new stimulus he secured almost uniformly a grade of one hundred per cent., and at the end of the year ranked at the top of his class. This incident illustrates the effectiveness of social pressure as an incentive to persistent attention and work. The principles of education of attention apply to the education of other mental capacities. The aim is not to increase the amount of any capacity, but to lead the child to make the best possible use of it. In regard to memory, William James has never been proven wrong. " No TRAINING OF MENTAL CAPACITIES 307 amount of culture," he wrote, "would seem capable of modifying a man's general retentiveness. This is a physiological quality, given once for all with his organi- zation, and which he can never hope to change." ^^ *' All improvement of memory consists, then, in the improve- ment of one's habitual methods of recording facts." ^^ It is true that the observations on which James based his conclusions were faulty. He conducted experiments indi- cating that practice in memorizing one kind of material does not improve one's speed in memorizing material of a different sort. They have since been repeated under more exact conditions, and it is to-day well established that practice with one kind of material aids in the memorizing of all kinds of material in any way similar to that used in practice. But this transference of training is due to an acquisition of correct technique of memorizing, or else to identical elements in the different kinds of material; and while improvement in the technique of study is highly valuable, it consists in a formation of habits which is within the capacity of persons of either good or bad mem- ory, and which aid rather than increase this capacity. The education of powers of judgment and reason is bound up with that of memory and attention. The child may be taught the technique of reasoning and led to apply his powers in this respect to problems lying in many useful fields of human endeavor. He may be encouraged to exercise his powers, and given the chance to acquire the knowledge upon which the success of their exercise is dependent. The first stage in the training of reasoning plainly is the provision of a wide experience extending beyond the class-room and embracing first-hand " '• Principles of Psychology," Vol. I, 1890, p. 663, ** Op. cit., p. 667. 3o8 EDUCATIONAL METHODS observation, so that the child may acquire a considerable knowledge of facts; for one cannot reason without facts. In higher stages, the child's attention may be directed to problems which lie in those fields of his own experience most likely to prove of value in later years. Here he requires help and encouragement, particularly in the mat- ter of learning, to test the correctness of his solutions by experiment. The capacity for emotion is clearly either strong or weak in spite of education. No education can make a phlegmatic person emotional nor an emotional per- son phlegmatic. The educational problem is to effect an association of the individual's natural emotional responses with the right situations. We cannot change the amount of elation of a child at success, but we can constrain him to give vent to this emotion only at the right kind of success. We can create new desires and destroy old fears. The proper treatment of fears and desires, said to be the two greatest motive forces of mankind, is one of the most difficult and misunder- stood, and, at the same time, one of the most fundamental, of all the problems of teaching. The emotion of fear in a child may be so strong and so easily aroused that it will completely stultify his mental development. A remark- able case has recently been described by Witmer, a pioneer in the psychological study of subnormal children, and an expert in their training, in which, apparently, a state not far from f eeble-mindedness was due primarily to excessive fears, leading to an ostrich-like inattention to every new thing or person. Once these fears were overcome, the development of the child's decided positive abilities pro- ceeded with amazing rapidity .^^ '""What I Did With Don^" Ladies' Home Journal, April, 1919, p. SI. TRAINING OF MENTAL CAPACITIES 309 Education must accept the capacities of a child as it finds them, and, by affording them every exercise possible, make them fit to render their greatest service. This does not necessarily mean that there is no value in formal exercises designed to develop this or that mental function. Memory lessons, attention lessons, and reasoning lessons have their use. They provide a mental technique, methods of mental procedure, which may prove useful in an end- less variety of situations. Very likely it would be wise to provide formal " reasoning training " for exception- ally bright children at the higher mental ages, just as we provide sensory and motor training for children of the lower mental ages. Such exercises could be patterned after the tests I have described in a previous chapter as tests of logical-mindedness — tests involving the ability to pick out from a number of reasons the best one in sup- port of a given statement, or to select the best conclusion from a number given as following certain specified prem- ises; tests requiring the formation of a principle; tests of analysis and synthesis, involving the process of pointing out likenesses and differences, and exercises in the formu- lation of definitions and the recognition of absurdities. The possible value of reasoning lessons, imagination lessons, morality lessons, and so on, needs further study. Such lessons might form a valuable supplement to read- ing lessons, history lessons and arithmetic lessons. By adapting our methods to the capacities of the child, by basing education upon an inventory of these capacities, we immediately become aware of numerous consequences of the greatest aid to our educational efforts. We find that we are providing exercises in which the child shows interest; that we are asking him to do things which he enjoys doing, because in their accomplishment he experi- 3IO EDUCATIONAL METHODS ences the best success of which he is capable ; that, because the appeal is to his natural interests, the child is willing to persist in his efforts in spite of fatigue and hardship. Of course, the teacher is never relieved from the necessity of broadening the child's interests, by associating them with allied interests; nor from the necessity of tlie judicial use of all the incentives to work which she commands, whether these be such natural ones as rivalr>% curiosity and the in- herent rewards of success, or such artificial ones as prizes and special privileges ; but she will find that she is working with the child instead of against him. Spontaneity and enthusiasm will be displayed by the pupil, so that the teacher may be transformed from a tiresome drillmaster into a guide to the child's best development. From the point of view of society, each child will be trained to his maximal usefulness, and prepared to fit into his proper place in the social organization. Social solidarity, the subordination of the individual to society, is not to be attained by attempting to make everyone alike. The unity of society is, and must be, that of a complex structure, not that of a sand-like, homogeneous mass. Consequently, by adapting our educational methods in the case of each child to his capacity for serving society, we pursue the course best calculated to preserve the integ- rity of the social organism, and at the same time best designed to develop that spirit of which democracies are so justly proud, the spirit of individual initiative and resourcefulness. INDEX OF AUTHORS Abelson, A. R., 158, 226 Anderson, H. M., 58 Anderson, M. L., 280 Aristotle, 214 Ashhy, H., 241 Ayres, L. P., 82, 95, 125, 131, 134 Bagley, W. C, 168 Baldwin, B. T., 118 Bean, R. B., 100, in, 115 Beik, A. K., loi Binet, A., 22, 149, 158, 194, 210, 282, 283 Bolxjrtag, O., 46 liolton, J. vS., 65, 77 Bonser, F. G., 178, 193, 265 liosbauer, H., 93 Bridges, J. W., 29, 58 Brenner, A. F., 293 Brown, Wm., 183 Brugmans, H. J. T. W., 230 Burt, C, 155, 184, 187, 189, 226 Cajal, I^mon Y., 63 Carey, N., 158, 165, 184, 230 Carman, A., 158 Carr, H. W., 198 Cattell, J. McK., 20, 21, 253 Chapman, . C, 142 Clousto , T. S., 93 Coler, L. E., 58 Colvin, S. S., 168 Consoni, F., 149 Crjmell, W. vS., 87, 91 Crampton, C. W., 100, 116 Dessfjir, M., 215 Doll, E. A., 44 Down, J. L., 25 Drummond, W. B., 86 Duncan, P. M., 25 Earle, E. L., 238 Ebbinghaus, H., 149 Elderton, E. M., 237 Esquirol, 25 Femald, G. G., 203 Fletcher, O. O., 216 Gall, 217 Galton, F., 9, 10, 19, 20, 240, 247 GiUx,'rt, J. A., 21 Gillette, A. G., 133 Godflard, H. H., 26, 29, 118, 242, 260, 266 Groszmann, M., 266, 291, 293 Gulick, L. H., 95 Hammarberg, J,, 75 Hardwick, R. S., 29 Hart, B., 223, 228 Heeter, S. L., 133 Henri, V., 22 Hetherington, C. W., 302 Heymans, G., 230 Hoffmann, A., 58 Holmes, W. H., 269 Itard, 276, 277 3" 3" INDEX OF AUTHORS Jackson, J. M., 105, 1 06 James, Wm., 306 Johnson, G. E., 184, 302 Jung, C. G., 171 Kclloy, R. L., 21 King, I., 229 Kitkpatriok, E. A., 81), 147, 298 Konihausor, A. W., 59 Kniepolln, E., 20 Kniogor, F., 154 Kuhhnann, P., 29, 41), 193-195 I^ipagc, C. P., 92, 95 I.iiuiaous, 45 lA)o\viMifoUl, L., 248 Lovvoll, F., 40, 135, 163, 173, 174, 194 Luiton, F. E., 127, 133 Macnamarn, N. C, 198 ^farshall, TT. R., 198 McCnW, \V. A., 164, 229 MoDiHigall, Wni., um, 198 MoMuny, C. A., 303, 304 Mcnill, M., 261 Momniuni, E., 165 Miklas, L., 93 Millard, W., 25 Minor, J. B., 33 Mitcholl, D., 260 MiMiroe, W. S., 142 Montessori, M., 278, 283, 284 Mooiv, A., 272 Moi-g:m, B. S., 281, 283 Morgan, C. L., 198 Myers, C. S., 161, 198 Norsworthy, N., 53, 179 Ordalil, ]<:. O., 89 Ordahl, G., 89 ratorsou, D. G., 53 Pearson, K., 237, 239 Pflaundor, M., 69 Pillshury, W. B., 227, 304 Pinel, 276 Pinlner, R., 53 Portcous, S. D., 56 Porter, W. T., 117 Pry or, J. W., 101, no, in Punnelt, R. C, 244 Pyle, W. II., 178 Rogers, A. C, 24 UcSiner, F., i7(>, 177 Roteh, T. M., 101, 115, 120 Rush, G. P. 142 Rusk, R. R., 167 Semnnion, R., 66 Sehiner, II., 93 Sehlosstnann, A., 69 SeJiuster, E., 237 S<5guin, E., 277, 278 Scverson, S. O., 109, 115 Sherlock, E. B., 169 Simon, T., 158, 210 Simpson, B. R., 178 Smith, M. K., 84 Sollier, P., 149, 189 Si^eamian, C, 154, 222, 223, 228 Spitzka, E. A., 74 Squire, C. R., 179 Staivh, D., 142 Stem, W., 149, 264 Stoner, W. S., 289 Stout, G. F,, 198 INDEX OF AUTHORS 313 Slrayer, G. D., 125, 127, 131 vStrong, E. K., 56 Swift, E. J., 158 Terman, L. M., 29, 49, 51, 58, Go, 120 Thorndike, E. L., 154, 213, 214, 216, 230, 240 'JVabue, M. R., 179, 180 Ward, L. F., 257 Watson, G. A., 65, 66, 72 Whipple, G. M., 164, 178 Wissler, C, 21, 221 Witmer, L., 84, 308 Woodrow, il., 37, 40, 133, 135, 173, 174, 187, 194, 228, 230, 297 Woods, F. A., 238, 247 Wundt, W., 149, 189 'JYcdgold, A. F., 79, 196, 241, 280 Wylie, A. R. T., 118, 169, 198 Wallin, J. }l. W., 265 Yerkes, R. M., 29, 58 INDEX OF SUBJECTS Abbie, 11/ Absence, from school, 136, 143 Absurdities, recognition of, 195 Achievement — capacity, test, 203 Acuity, visual, of school -children, 85 measurement of, S^ff Adenoids, 82, 84, 88, 90/ Administration, educational, 143^, 258/ of medical inspection, 96 Advancement, pedagogical, 127/ After-care, of feeble-minded pupils, 273/ Age, anatomical, 97^ educational value of, 118^ indices of, loojf meaning of, 99 mental ability and, 112^7" school grade and, 115 sex differences in, iioj/"., 121 variability in, io6jf chronological, 26, 97 mental, 24/, 97 concept of, 25/, 30 distinction from brightness, 41 measurement of, 26jf in adults, 52 in business men, 51 year of as unit, ^6ff pedagogical, 123^^ brightness and, 125 definition of, 124 two meanings of, 100 Ages, various, of child, 97 Amentia, meaning of, 45 Analysis, test of, 195 Areas, cortical, 219 Army, U. S., tests for, 39 Asexualization, 273 Associates, paired, method of, 182 Association, analysis of, 172, 177 controlled, 177/ free, 171/ intelligence and, 176/ law of, 172 mental, I7ijf Atomism, psychological, 213/ Attendance, school, 136, 143 Attention, and intelligence, 149, 189, 196, 226/., 230 conditions of, 297Jf definition of, 185 degrees of, 185 in children, 30i# in idiots, 300/ measurement of, 186^ motor accompaniments of, 185 training of, 282, 296/f Automatism, 208, 211/ Aveyron, savage of the, 275jf, 298 Backwardness, 54 Behavior, intelHgent, and mind, 147/ meaning of, 147 Biometrics, and heredity, 234^ Bones, cuneiform, no, 112 forearm, 104 315 i6 INDEX OF SUBJECTS Bones, hand, 105 mtelligonco and, 115/ pisifomi, 109/, 112 VNTist. 1 03,//" Bnun, 6i# action, 217/, 227/ body and, 81, 117 intelligence and, 62_^ Brcslan, 57 Brightness, age at which deter- mined, 70 degrees of, 45/, 54 exceptional cases of, 9/, 35/, 248#, 286/f, 306 meaning of, 41 Byron, 36 Cambridge, scliools of, 267 Cancellation, test of, 163/ Capacities, age at which deter- mined, 252, 256 sensor>% 154J?* training of, 279./f, 296jf Cells, brain, 63/, 7i/77Jf Census, of feeble-minded, 274 school, 144 Character, 38, 138, 197, 264, 292 Classes, auxiliary, 259, 268, 270^ furthering, 267Jf special, 142/ ungraded, 27q|f Classification, of brightness de- grees, 54 of children, 42jf Commission, Royal, on feeble- minded, 43 Completion, tests of, 179/ Corrtvtion, of physical deftvts, 96 Correlation, memiing of, I52jf negative, 159/ Cortex, brain, 63jf brightness and, 94 childivn's. 72 idiots', 79 vertebrates', 6T,ff Courses, parallel, 143 physical culture, 144 Courts, juvenile, 38, 172 Criminality, 38, 91 Cimiculum, simplified, 141, 269 Deafness, 88 Defects, age and, S2 intelligence and, S2ff physical, 8ijf scholarsliip and, 134 Defining, tests of, 193/ Degenei*acy (see Stigmata) Dentition, 101/ (see Teeth) Detraction, 187 Development, prediction of, 118 rapidity of, 113 Diagnosis, mental, 16, ^Sf, 60, 93, 113, 118, 260 Differences, individual, 13, 47/, prediction of, 108 raci;xl, 56, 103, 159/f sex, 31, 103, no/, 121, 134 social, 57/f Disabilities, special mental, 293 Discrimination, sensor}'', 151/ intelligence and, 1 54/ racial differences in, i^^ff tests of, I5i./f training in, 27Qf, 284 Diseases, communicable, 95 INDEX OF SUBJECTS 317 Distraction, 187, 301 Distribution, age and grade, 128/7" of intelligence quotients, 53/ of mental ages, 31^ normal, 32 Docility, 211 Dotting, test of, 187/ Dramatics, 302 Dullards, 11, 36 Dullness, definition of, 42, 54 education and, 259^, 266^ Duty, training sense of, 305 Education, 139/, 146 for bright and dull, 258/, 266/ Edwards, Richard, descendants of, 249# Efficiency, factors of, 229^^ Elimination, 127, 131/ Eminence, inheritance of, 247Jf Emotions, 138 abnormalities of, 201 training of, 308 Energy, cortical, 227/ Entrance, school, age of, 123 Environment, 232^ Binet tests and, 36/ growth and, 255/ mentality and, 239, 240, 242, 25i# normality of, 233/ Epiphyses, 105, 106, no, 112 Ergography, 204/ Evolution, of brain, 80 of intelligence, 160 Examination, medical (see Inspec- tion) Expedition, Cambridge Anthro- pological, i6o# Eye-color, inheritance of, 235 Eye-glasses (see Spectacles) Eye-strain, 87 Factors, specific mental, 224/ general mental, 226^ intermediate mental, 229^^ Faculties, mental, 215, 296 physiological method and, 278 training of, 309 Failure, 126, 140, 145 causes of, 35, 133/ Fame, Hall of, 248 Families, feeble-minded, 243/, 245/ Far-sightedness, 86f Fear, 308 Feeble-mindedness, definition of, 43/, 53/ elimination of, 272/ importance of, 15 social aspects of, 43/ Feelings, 168/ Forecasting (see Predicting) Freshman, Columbia tests of, 20 Minnesota tests of, 39 Frequencies, association, I73# Galton, as child, 9/ Games, 301/ Genius, cases of, 10, 36, 286/ inheritance of, 247, 248/ opportunity and, 257 Glands, 82, 90 Goldsmith, 36 Grades, of brightness, 42/, 54 Grading, of children, 142 3i8 INDEX OF SUBJECTS Groups, tests of, 40 Growth, age limit of, 50 brain, in cliildren, 68/ education and, 254/ environment and, 255 heredity and, 252 learning and, 37, 70 mental, 48 skeletal, 106 Headaches, 87 Hearing, 82, 88 of savages, 162 tests of, 89, 95 Height, 117/ Heredity, 232jf education and, 253, 254/ growth and, 252 importance of, 25ijf methods of investigating, 2S^ff Histories, family (see Pedigrees) History, of mental measurement, Home, mental effects of, 239, 240 Hydrocephalus, 74 Idiocy, 43, 44. 54, 98 Illiteracy, 256 Imagery, 165/ intelligence and, 167 tests of, 166 thought and, 167 Imagination, training of, 282 Imbecility, 43, 44, 54, 98 Impulsiveness, 211/ Indices, of anatomical age, loojf Individuals (see Differences) Inefficiency, social, 44 Inheritance, mental, 237/ Inheritance, physical, 236, 238 Insanity, as cause of feeble-mind- edness, 242 Inspection, medical, 94/, iiSjf, 144 relation of, to teacher, 96 Instincts, I97jf attention and, 297/ in feeble-minded, I98jf intelligence and, 197/ sexual, 200, 212 social, 306 Institutions, for feeble-minded, 272/ Instruction, by subjects, 142 Intelligence, definition of, 36, 37, 41, 51, 148, 213, 229 errors in measurement of, 55 estimates of, 156/ measurement of, 19/, 55 mind and, 147/ organization of, 213^ relations of, 14/ science of, 16 success in school and, 33jf, 137 value of knowledge of, 17, 295 Interests, 299/, 303 Interrelationships, mental, 150, 213/ Intuition, 191 Kallikak, Martin, descendants of, 245# Knowledge, acquisition of, 37, 51 needed by schools, 257 Language, school success and, 135 tests of, 179/ INDEX OF SUBJECTS 319 Layers, cortical, 63/ pyramidal, 63/, 72 Learning, brain changes and, 71/ growth and, 70 measurement of memory by, 183 mental age and, 37 Letters, teaching of, 287/ Levels, intelligence, 113 Localization, of brain functions, 218/ Lock-step, 128, 142 Logical-mindedness, I93# Malnutrition, 106 Mannheim, schools of, 267/ Marriage, laws against, 274 Matings, of feeble-minded, 242/ Maturity, 55 Median, definition of, 30 Memory, 180/ as a capacity, 230 association and, 180/ in feeble-minded, 184 intelligence and, 183^ other mental processes and, 185 tests of, i8ojf training of, 281, 286, 306/ Mendelism, 244 Mentality (see Age, mental) Methods, educational, 275,^ physiological, 277^^ criticism of, 283^ Microcephalus, 79 Mind, body and, 61/ intelligence and, I47jf Moron, definition of, 44/, 54 Movements, training of, 280/, 282 Multifactorism, theory of, 229jf Multifocalism, theory of, 215, 220 Musicians, childhood of, 10 Nationality, and scholarship, 135 Near-sightedness, 86/ Neglect, parental, 96 Negroes, intelligence of, 56 Neurones, 63/, 71 functioning of, 227/ Non-focaHsm, theory of, 213/, 221 Normality, anatomical, 119 frequency of, 54 inheritance of, 247 of school grade, 123/", 129 Nurse, school, 96 Nutrition, and mental capacity, 240 Occupations, for feeble-minded, 260, 261 Opposites, I77# and intelligence, 178 Organization, educational, 2$%ff of associations, 177 mental, and correlations, 22oJf three theories of, 214^, 220 Orthopedics, mental, 282 Ossification, carpal, 103^ mental development and, ii5# sex differences in, 112 variability in, 109/ Overstrain, 119/ Pain, sensitivity to, and intelli- gence, 158 Palate, 90, 93 Papuans, senses of, 161 Parallelism, of school courses, 143 psychophysical, 61 20 INDEX OF SUBJECTS Pedigrees, for study i>f hnvdity, of ftvble-mindod, J41.//", --ks.f/* t^f superior iuteIli^>;oiu\^s, 247.//' IViveption, ibjff intelligence aud, 104 tests of, U\\Jf Perseveration, 176 Persistence, of will, 202 ff tests of, 202ff Pei"sonality, in intelligence testei"s, 39 Phrenology, 217 Play, 301/ Pleasantness (see Feelings) Popidation, and grade distribu- tion, 129 Porto Rico, 135 Predicting, development, 118 individual ditTercuces, 108 nientid age, ^^xf, 52 cvcupation, 2bo Pnxiigies, juvenile, 9/, 3(\ 2St\tf Pmgnosis (see Pivdicting) Progress, rates of, 258jf, 267jf Promotion, by snbjects, 142 mental age and, 34 spcciiil, 35, 2q$ Psychology, experimental, 278/ Pubescence, 107 SL^hoUirship ami, 116 vaiiability in, 108/ Questions, as aid to attention, 303/ Quotients, intelligence, ^Sff constancy of, 49 definition of, 49 significance of, 55 use of, ^2ff Quotients, intelligence, variability R., Louis, 35 Races (see Differences) Radiographs, 103, no, 112 Reactions, time of, 21 Reasoning, 190//' definition of, 190 intelligence and, 150, 191 tests of, n),\ff. t nulling of, 307/, 3(X) Reliability, of measurements of intelligence, 55 Reprixluction, by memory, 181 Retardation, l)edagogical, 124/ by gmdes, I26jf, 132 causes of, 133/, i30# extent of, \2^f in Minnesota, 127, 133, 135 increase in, with age, 138 invisible, 145 remedies for, li^c^ff yeai-s of, 126 mental, increase in, with age, 46 meaning of year of, 46^ Retention, measuirment of, 183 Revisions, of Binet scale, 29/r, 40 R(!Sntgenographs,(seeRadiographs) Royalty, heredity in, 238 vScale, Binet, 27, 28 accumcy of, 30 criticism of, 36Jf popularity of, 24 revisions of, 29jf, 40 success of, 23/ INDEX OF SUBJECTS 321 Senses (see Discrimination, Vision, Hearing) Sensitivity (see Discrimination) Sex, and school success, 134 (see Differences) Sheaths, of nerve fibres, 71 Siblings, resemblances in, 237/ Simplification (see Curriculum) Solidarity, social, 310 Spectacles, 84, 87, 135 Spelling, and heredity, 238 Stages, anatomical, 99 mental, 113, 114 Standing, pedagogical, I25j9" Status, social, and intelligence, 57^ and physical development, 1 18 Stereotypy, 212 Stigmata, of degeneracy, giff significance of, 93 St. Louis, schools of, 129/ Stoner, Winifred Sackville Jr., 289# Structure, brain, 62^ gross defects in, 78 in adults, jsff in children, 71/ in vertebrates, 6^ff Subnormality, 55 Success, causes of, 13/, 59 , I33j^ Suggestibility, 208/ kinds of, 211 tests of, 209/ Superiority, cases of, 9/, 35/, 248/, 286/, 306 definition of, 42, 54 Supernormals, education of, 262^, 268, 286/, 305/ Supervisors, of individual work, 269/ Surveys, mental, 40 Synthesis, tests of, 195 Talents, special, 292 Teacher, knowledge needed by, 17 Teeth, 82, 90, 10 if, 107/ Tests, aljsurdities, 195 achievement-capacity, 203 anatomical age, Kxjff association, free, lyiJJ" attention, i86J/^ cancellation, 163 completion, 179 definition, 193^/" discrimination, 151 dotting, 187/ ergograph, 204^ far-sightedness, 86 group, 40 hearing, 89 imagery, 166 intelligence, 26/, 55, 295 language, 180 learning, 183 memory span, 183 mental age, 26^ opposites, 177 paired associates, 182 perception, 163 reasoning, 193 ff sensory, 151 suggestibility, 209^ synthesis, 195 visual acuity, 84^ will, 202/ Theory, multifactor, 229^?^ multifocal, 215, 220 non-focal, 213/, 221 Spearman's two-factor, 233^ unifocal, 216, 221 322 INDEX OF SUBJECTS N Thinking, 171 Thought, and iniagen', 167 Tiine, reaction, 2 1 Tonsils, Sj, 84, 9of Training, gTO^^'th vs, 254^ in early childhood, 255 motor, 2 So/, 2S2 of attention, 282, 296^ of capacities, 296^ of dull children, 259/, 266/f of emotions, 308 of faculties, 509 of idiot, 276/ of imagination, 282 of memor>% 281, 286, 306^ of reasoning, 307/, 309 of sense of duty, 305 of supemormals, 262/, 268, 2Sbff, 305/ sensor>', 279/, 284 transference of, 307 Transference, see Training Tniancy, 127, 144 Tuttle. Elizviboth, see Edwards T^^•ins, measurements of, 240 Underfeeding, 105 Unity, mental, 216, 221 Unpleasimtness (see Feelings) Variation, in anatomical age, io6Jf Vision, $2, 84/, 95, 135 Waste, educational, 260 Weight, body, 117/ bmin, growth of, in children, in adults, 73/ in eminent men, 74 in vertebrates, 62 intelligence and, 74^ Will, defects of, 202^ deiinition of, 201/ instinct and, 201 IFF r / n G <^;. * 9 N V .^*. a 0' C^- * N z s ^ A '^ -^ , X -^ ^6 , < -X ^^^ .^^'^ %^^ .<^^^. x^^'^^.. ^ ^^^^/% ^ -^ « ^ .^ ^ ^v aO *y ^. V 1 8 ^ •-v^..,>: ^J c ^1^," ', "^ ?^' ri^M<^^ '^. ^'^ .^^^ ^ '■^'y^,^ f N .•^ -^c^^ \n^^ '^^z^ ' , \4^'^^^ > oo^ ^A V ^c*^^"^^'^^^^'.* Sj5' ^' \