UNIVERSITY OF CALIFORNIA AT LOS ANGELES GIFT OF WILLIAM WEBB KEMP EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES gfturatumal Etittra bfl P P po 2 to i -" O P 95 i 552 * t I M I-H X M HH a" SS-J C ^ Q^ j^ i SB 5jf ! S to CO tO M CO 00 4k CO CT M M M CO CO -J CO f , ,. ciccoS-- O O B" p to D-l >< GO *< M S to M to -^ i-i x co CO C> 10 00 Ci X 1 * 2.* |jf(J5 g 1 bo Ci -3 CO 00 M Ci CO b b -^ M co M ^ ^ S S- o> 3 cr 9 1? J P* S* Q .i;* 1 ^_A ""1 l-i tO I-i tO to M ~\ >? 93 tr* ,3 B CT CO "^ CT O1 -J CT CO -1 CO tO 4k 4k tO IsJo^ CD B" os B" 2 99 HH <* *""" <* O _^ a I-i IO M *. CO CO 00 -J to t-1 ^ Ci tO M CO CO MM . p "2 w Cd s bo bo CO b 4k ^ 4k Ci 00 H-i Ci -^ 4k 4k "^ -^ G ^ C". * 5' ' > co to W f^ . H 1 i-, D ^ &> CO IO to M P l_j g en r^- QB ^5 3fq GC "' CO CT 10 CO 10 CT 4k CT OS P o S M to M Ci to i-i to I i e H 8 12 o 60 tO 4k CO 00 X 4- M 4k CO 4k CT JJ" 2 i. HH CT Iq ~1 Ci Ci CO CT M Ci -q Ci CT b Z 1 CO 00 Ci 00 -J IO CD CT CO CO I- 1 4- co i i o2 CC ft ^2 f^- (W O i, ($ M 4. CT CD 4*. CT CO O 4k.CC M M -^ 4- I ' co O b * 00 CT Ci -1 CO - 1 Ci O I-* X CO CO -q to x D "^ 3 50 g S ^, S 4k^,^Ko *J M l-l 00 M Ci CO CO X -^M?5 5 p 3 3 ' S 2.1 b tO M CO tO CO CO CO IO Ci Ci X. 3" B* *^ 4 to to 5 CT 3 5* s:la^ CC 8 I-* tO GC tO CT M 00 CO 00 CT CO CO tO I i i i I i 10 10 o ci >-> l-i CO 1 l X-- >, CO C. ? C t 5": M% D J3* ^ o tO l-i 10 i - * B 1 CT h- 1 CO GC 4- 00 Ci CO Ci CO 4- CO CT CO t-*<)0' < ' 4- CT CO 4 b 4 CT CO Ci Ci b bo co 4 _ 00 1 g a t c- 1 5' H 52 14 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES Confining our attention to the gross or the group classification, it is seen that the 333 1 epileptics in- cluded in Table I classify as follows : 5.7% are idiots (mentality of I and n years), 27.3% are imbeciles (mentality of III to VII), 61.5% are morons (men- tality of VIII to XII), and 5.4% have a mentality of XIII years or over. 2 In all, 82.8 % have a mentality of less than eleven years. The idiot and the XIII- year-olds are about equally infrequent, while the morons are decidedly preponderant. These results will attain added significance if we compare them with the B.-S. distribution for the 378 feeble-minded inmates tested at the Training School in Vineland, New Jersey. 3 Nineteen and two-tenths per cent, of the feeble-minded are idiots, 54% are imbeciles, 26% are morons, not a single one grades as thirteen, and 96.4% grade less than eleven years of age mentally. 4 The feeble-minded idiots are about three and one-half times as numerous as the epilep- tic idiots, and the feeble-minded imbeciles about two times as numerous as the epileptic imbeciles. On the other hand, the epileptic morons are more than two epileptics were excluded from the tabulation who had not had a convulsion within a period of two years, and a few others who were not thoroughly tested because of certain sensory defects. The number of patients of each mental age is shown in Table I. The patients were in their normal condition during the testing. Patients who passed in two of the 13-year tests w T ere credited with this age, provided they also passed at least five tests in Ages XI and XII. Drawing one triangle was accepted for the first of the 13-year-old tests. 2 Ages printed in Roman numerals throughout this monograph refer to mental as distinguished from chronological age, and refer to the mental ages indicated in the Binet-Simon scale. 'Henry Herbert Goddard, Journal of Psycho-Asthenics, 15 (Nos. 1 and 2), 1910. *The per cents, for each age are as follows : Age I, 9.5% ; II, 9.7% III, 10.5%; IV, 9.8%; V, 11.1%; VI, 10.2%; VII, 12.4%; VIII, 11.6% ; IX, 7.9% ; X, 3.7% ; XI, 1.3%, and XII, 1.8%. BINET-SIMON SCALE FOE CLASSIFYING DEFECTIVES 15 and one-half times as numerous as the feeble-minded morons. While the great mass of people in both of these classes of defectives have a mentality of less than XI years, the proportion is 13.6 % greater among the feeble-minded than among the epileptics. As found in institutions at least, the typical epileptic condition is moronity (five-eighths of the entire num- ber), while the typical feeble-minded condition is imbecility (more than one-half of the entire number). These figures indicate that there is a marked dif- ference between the grade of intelligence of epileptic dements and that of feeble-minded retardates. 1 One reason for the superiority of the epileptics may be the fact that, relatively, a larger number of the feeble-minded than of the epileptics were youths. Fifty per cent, of the feeble-minded were under 21, while only 30% of the epileptics were under 21. As the B.-S. scale is now constituted, it may be assumed that defective adults will grade somewhat higher than defective children, as is indeed indicated in Table I. Sixty-five and four-tenths per cent, of the adults are morons (mentality of from Age VIII to Age XII, inclusive), while only 53.6% of the children are morons, and 7.1% of the adults grade XIII years as contrasted with 1.8% of the children. The adults among defectives possess a larger storehouse of ex- perience and acquired knowledge. At the same time, the epileptic superiority will attain added prominence 'Space does not avail to point out the practical implications of this fact, but we may emphasize a growing conviction that epileptic and feeble-minded persons should not be huddled together in the same institution. The differences in the mental station not to mention other significant differences between these two classes are such that they can be most humanely cared for in separate institutions, or at least in separate divisions in the same institution. 16 EXPERIMENTAL STUDIES OP MENTAL DEFECTIVES if we constitute the XUI-year-olds a separate class above the feeble-minded line, which we may regard as normal, or as retarded or deviating, though not to such an extent as to render the individuals feeble- minded. We should then have to add to this class all the epileptic children who are retarded less than three years (children retarded less than three years should probably not be rated as feeble-minded). There are nine of these five boys and four girls. Adding these to the XUI-year-olds, we get a total of 27 1 normals, or deviates, which is 8.1% of the entire group. This figure (8.1%) we are justified, I believe, in regarding as a lower limiting value for two reasons. First, the tests in the higher ages are, as will be seen in later pages, too difficult for the typical American child for the ages to which they are assigned. To get a check on these higher tests, I made use of the fol- lowing means: A few of the supervisors and offi- cers at Skillman who had known the patients inti- mately for a considerable length of time were asked to prepare estimates of the number of patients whom they regarded as ranking above the feeble-minded station. Three of these officers, quite independently, made for the total population the same estimate, namely, 10%. Five men made separate and inde- pendent estimates of the total male population as follows : 11, 11, 13, 14 and 20%. With one exception, these estimates agree fairly well. With the tests as at present constituted, it is a question whether the line of feeble-mindedness should not be drawn be- a lt is interesting to note that among these 27 there is only one who can be regarded as above normal, a boy somewhat less than twelve years who grades as thirteen. BINET-SIMON SCALE FOB CLASSIFYING DEFECTIVES 17 tween eleven and twelve instead of between twelve and thirteen, as has been done tentatively by the American Association for the Study of Feeble-Mind- edness. A number of our Xll-year-olds certainly are very slightly, if at all, feeble-minded. A second reason why the percentage of normals may be too low is the fact that the institutional cases at Skillman may not be representative. Our curve in general is valid on the assumption that the epi- leptics tested are typical. According to the theory of the probability surface, we are justified in regard- ing them as typical, provided the selection repre- sents a chance distribution. But it is possible that two selective processes have operated in a way to distort both extremes of the curve. The reason that the idiots are so few may be due to the fact that the higher grade epileptics have received preference in admission to the institution. The introduction of a constant factor of this sort would skew the fre- quency curve in the direction of the upper limit. This tendency would probably stop short, however, before it reached the extreme end of the curve, be- cause it is also probable that the highest grade of epileptics from the better social classes are very rarely found in State institutions. We shall not be able to settle this point definitely until other institu- tions have prosecuted similar studies on a larger scale. In spite of these elements of uncertainty, the above facts seem to warrant three general conclusions: First, that the great mass of epileptics (possibly from 85 to 90%) fall below the feeble-minded line- just how much inferior the higher grade epileptics are to those persons taken at random in the general 18 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES population whose schooling and training are about of the same character we shall be in no position to say until comparative studies by identical methods have been made ; second, that they do not fall below this line to such an extent as the amented feeble- minded class ; and third, that the curves of distribu- tion differ markedly for the two classes, a fact to which we shall now direct attention. One of the significant traits of the epileptic curve is its decidedly skewed or anomalous character, noticeable particularly between Ages VIII and XI. The curve presents a marked contrast to the curve of feeble-mindedness in respect to its frequency sur- face. The latter curve is characterized by a fairly uniform rise up to and including Age VII, and by a rapid and uniform fall after Age VIII. It has more or less of the normal bell-shaped appearance. But in the epileptic curve there are two irregular drops in the ascending portion, a minor at V and a major at IX. The former does not possess much significance because of the small number of subjects tested in the lower ages. It may be regarded merely as a fortui- tous phenomenon. But in a typical curve of fre- quency the rise from Age VI would have continued without any marked break at IX to the apex at X. It is apparent, therefore, that those accidental factors which normally operate to produce an unskewed or bell-shaped curve of frequency were rendered more or less inoperative in our testing by some constant factor or factors. These factors may reside in the method of giving the tests, in the method of scoring, in the defective nature or arrangement of the tests themselves, in the peculiar mental organization of the epileptic (either as a result of inborn constitu- BINET-SIMON SCALE FOE CLASSIFYING DEFECTIVES 19 tion or as a result of the disorganizing processes of the disease), or in the averaging of the results for both defective children and defective adults. For example: We find 24.9% of the epileptics grading X years old, as against 8.4% grading IX years old; hence, either there must be certain defects in the mentality of epileptics at the IX-year level, or we must consider the X-year-old tests as normally too easy, or the IX-year tests as too difficult, or other- wise some factor extraneous to the tests themselves has been operative. In order to arrive at a correct explanation of the skews in our epileptic curve we shall, in Chapter II, undertake a minute analysis of the data. CHAPTER H. TESTING THE BINET-SIMON TESTS : AN EXEMPLIFICATION OP AN ADEQUATE METHOD OF ANALYSIS. In the preceding chapter we noted the approxi- mate conformity of the feeble-minded curve to the normal probability surface, and the skewed charac- ter, or the distinct divergence of the epileptic curve from the bell-shaped distribution which would, on the theory of probability, be expected from the test- ing of a homogeneous group of individuals. If the skews cannot be shown to be due to the method of scoring, or the method of testing, or the combining of the records of juvenile and adult epileptics, they must be ascribed to fundamental peculiarities or anomalies in the mental make-up of the epileptic. The epileptic is not only retarded, and thus some- what like other amented or demented individuals, but his mental mechanisms are so irregular, atypical or deviating ( shown particularly by the ability which he frequently manifests to pass tests in many higher age-levels) that he is apparently qualitatively differ- ent from his first cousin, the feeble-minded person. But the law of parsimony requires one to make every legitimate effort to explain the peculiarities in the epileptic curve by the lesser causes before ascribing them to inherent abnormalities in the epileptic mind, so that I shall begin my analysis by an examination of the method of testing and the method of scoring. 20 TESTING THE BINET-SIMON TESTS 21 I tried, of course, in testing, to conform as closely as possible to the instructions laid down by the au- thors (Binet- Simon), and particularly to the syl- labus prepared by Goddard. Having worked in Goddard's laboratory, I was in a position to follow the methods in use in Vineland. In one rather im- portant detail, however, my testing differed from the Vineland procedure: I employed a wide-range method of testing; that is, instead of confining the testing of the patients to the ages immediately be- neath or above the ages in which they graded, I tested the majority throughout the greater part of the scale. This was done, not merely to arrive at a more complete clinical picture to reveal the pecu- liar mental lapses, gaps and remnants, the presence of which may be assumed to characterize degenera- tive or involution changes but in order to test the reliability of the scale itself. For the latter purpose nothing but a wide-range survey will suffice. 1 This method of testing gave rise to a rather serious complication in the matter of scoring, for it some- times happened that a subject might, say, pass all the ages up to and including Age V, fail on Ages VI, VII, VIII and IX, but pass Age X and also a few individual tests in the ages beyond X. It is evident that a record of this kind would admit of a two- or three-fold basis of scoring: we might use as the basis of scoring either Age V, plus advance credits from Ages VI to XII or XIII, or Age X, plus advance credits, or we might use the average of the ratings from these two methods. Age V would be regarded as the first or lowest age, beginning below, which was 'Such a survey must be made, of course, primarily on large masses of normal children. 22 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES successfully passed, and Age X as the last or highest age successfully passed. 1 In case the basis of grading were the first or lowest age successfully passed, this process of wide-range testing would create marked discrepancies between the results of different investigators, because through the process of wide-range testing many pa- tients would be able to win advance credits from higher ages, and this would enable them to reach a higher classification. At the same time it would make it possible for abnormalities to appear in the curve which would be concealed by a narrow-range system of testing. As a matter of fact, scores of our low or medium grade epileptics passed one or more tests in five, six, or even seven higher age-levels, and scores won from ten to twenty (or even more) points in advance of the first or lowest age in the scale which they were able to pass completely. It follows, there- fore, that many who passed higher-age tests failed on lower-age tests. To show how extensively pa- tients who passed some of the higher-age standards failed on the collective standard fixed for some lower level, the subjects have been classified in Table II according to two bases of rating: A, the highest or last age passed completely, plus advance credits; and B, the average of the first or lowest and the highest or last ages passed, plus advance credits in each case. To illustrate what is meant by these two methods of grading, we will suppose that a given patient passes Age X, fails on Age VI, but passes Age V, and that he passes 5 tests in VI, 5 in VII, 4 in VIII, 3 in IX, 3 in X, 2 in XI and 1 in XII. Ac- x An age is "successfully passed" when all its tests or all but one are correctly performed. TESTING THE BINET-SIMON TESTS 23 cording to Method A, the subject would be rated as having a mentality of 10.6 years (Age X plus 3 ad- vance points) ; and, according to Method B, as of 10.1 years (10.6 + 9.6 1 -r- 2). TABLE II. Differences arising from Grading Patients by two Methods: A, basing the Grading on the Last (or Highest) Age in the Scale success- fully passed, plus Advance Credits; and, B, on the Averages of both the First (or Lowest) and the Last (or Highest) Ages suc- cessfully passed, plus Advance Credits in each case. Entire Method. Age. Boys. Girls. Children. Men. Women. Adults, population. A IX 8?9 7.0 8.1 8.7 8.3 8.5 8.4 B IX 12.0 11.6 11.8 19.0 16.6 17.8 14.8 D 3.1 4.6 3.7 10.3 8.3 9.3 6.4 A X 23.8 18.6 21.8 23.4 29.6 26.5 24.9 B X 22.4 16.3 19.3 16.5 23.1 19.8 19.5 D 1.4 2.3 1.5 6.9 6.5 6.7 5.4 A XI 8.9 4.6 7.3 13.0 4.6 8.8 8.4 B XI 7.4 2.3 4.8 13.0 4.6 8.8 6.8 D 1.5 2.3 2.5 0.0 0.0 0.0 1.6 A XII 3.0 2.3 2.6 4.3 2.7 3.5 3.0 B XII 3.0 2.3 2.6 5.2 4.6 4.9 3.7 D 0.0 0.0 0.0 - .9 1.9 1.4 - .7 A XIII 3.0 1.8 7.8 6.5 7.1 5.4 B XIII 3.0 3.4 1.8 2.6 2.7 D 0.0 4.4 4.7 4.5 2.7 A and B as above. D=difference between A and B. Minus sign indicates a smaller per cent, in a given age in the A method. It indi- cates a loss instead of a gain. It is noteworthy that there are only 7 general averages which are identical, as against 21 which are different. Considering, first, the results for the en- 'Age V+23 advance pointR=9.6. 24 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES tire population (last column), it is seen that the differences for Ages XI and XII are small, 1.6 and .7%, respectively, while they are quite material for Ages IX, X and XIII, namely, 6.4, 5.4 and 2.7%, respectively. The result of basing the grading on the highest age passed, Method A, is to reduce con- siderably the number of IX-year-olds and slightly the number of Xll-year-olds, and to increase the X-, XI- and Xlll-year-olds, particularly the first and the last. (No one was credited with Age XIII who did not pass two of the tests in that age drawing one of the diamonds was accepted as satisfactory or who, passing Age XIII, did not pass five of the nine tests in Ages XI and XII. On this basis, 10 who passed Age XIII were rated as of Age XIII, while 12 failed. Five who failed in Age XI passed Age XII. A few passed X and XIII, but failed on XI and XII.) Below the ninth year the distribution remained the same except in three ages Ages V and VI for girls (a difference of 2.4% in each age), and Age VIII for women (a difference of .9%). In respect to the gross grouping, the per cents, of idiots, imbeciles and child morons remain the same, but there is a diminution of adult male (4.37%) and female (4.6%) morons, and a corresponding increase of XHI-year-old adults. In comparing the results for the children and adults it is seen that more adults than children ad- vance from Age IX to X and from XII to XIII by the A-method. Incidentally, it may be remarked that the differences in general are greater for the adults, which would seem to indicate a greater loss of lower- age capacities as a result of epileptic degeneration. Among the children there is no difference in Ages TESTING THE BINET-SIMON TESTS 25 XII and XIII. The girls, however, profited more than the boys, losing more in IX and gaining more in X and XI an indirect indication of the intel- lectual superiority of the boys (to which we shall revert later), since a larger percentage of boys were able to pass the harder tests. The difference be- tween the men and women, on the other hand, is insignificant. A detailed examination was made of the individ- ual records of the children (used in the sense of all under 21 years of age), in order to determine the amount of the disturbance. It was quite consider- able in one-third of the 103 cases studied. The grad- ing of 70, or 68% of the 103, dropped into a lower age classification when the B-method was used sometimes, of course, because of a difference of only one or two points. But in some cases the grading by the B-method was actually higher. This is due to the fact that some ages contain more than five tests, namely, ages VI, VII, VIII and IX. This ex- plains in a measure why the grading remained prac- tically the same in the two methods for the middle ages. Patients who failed to pass Age VI and all Vl-year-olds did, as we shall see but passed Age VII, could secure a higher rating from Age V than from Age VII. Finally, the rating remained in the same age classification with the two methods in the case of 32% of the patients. With 14, or 13%, of these subjects the difference amounted to a whole year (that is, five points) or more, namely: one year for three patients, 1.2 1 for three, 1.4 for two, 1.6 for one, 2.0 for one, 2.2 for two, and 2.4 for one. 'One point=.2. 26 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES The range of the possible difference of rating, due to a difference in the method of computing credits, . will be seen to better advantage if we compare our first method, A, with a third method, C. Instead of using the average of the rating from the highest and lowest ages passed, as in B, let us use only the lowest age passed as the base, with advance credits as be- fore. The difference in points thus amounts to one year or more in the case of 41, or 39 % of the children, as follows: Difference in years 1. 1.2 1.4 1.6 1.8 2. 2.2 2.4 2.6 2.8 3.2 Number of patients. . .12 6361251221 The difference thus amounts to two full years or more in the case of thirteen patients truly a signifi- cant difference. But, large as these discrepancies are, the question may still be raised why they are not yet more extreme, since some patients who fail to pass a lower level may pass sundry tests in a half- dozen or more higher ages, and all the tests in some one age (e. g., Age X) three or four years higher than the lowest age satisfactorily passed. The an- swer is to be sought in the corrective formula (one year of advance credit for five advance points), by virtue of which subjects may gain several years from the lowest age passed. Consequently the difference between the A-method and the C-method of scoring, and particularly between the A-method and the B- method, are oftentimes quite negligible. Since the difference in the mental station or classi- fication of epileptics may amount to two or three years, due entirely to the particular method of grad- ing adopted, it is evident that the results of different workers have no comparative value unless precisely TESTING THE BINET-8IMON TESTS -< the same system is followed. Accordingly, I adhered to the plan prescribed by the authors (Binet-Sirnon), which is followed by the workers in this country, according to which the subjects are credited with the highest age passed successfully (all the tests or all but one), plus advance credits (one year for five points) : in other words, I followed what I have termed Method A of scoring. Our survey of the facts up to this point justifies the following conclusions : (1) A difference in the method of grading may perceptibly alter the distribution of homogenous groups of patients, particularly in Ages VI, IX, X and XIII, and in the moron and retardate groups, and may thus vitiate results for comparative pur- poses. (2) This difference in rating may vary from con- siderably less than one year to more than two years. (3) The obvious effect of the standard method of rating, A, is to elevate the grading (except in a few of the middle ages) : epileptics failing at lower levels often pass higher ages. (4) The B.-S. Age IX is more difficult than Age X, and apparently Age XII than Age XIII, for epi- leptics. (5) Although it is advisable to follow the Binet- Simon method of accrediting (adding advance points to the highest age passed), it is obvious that when very large percentages of homogenous groups fail at certain lower levels while passing a higher level we have strong presumptive evidence that we are dealing either with special, aberrant or deviating groups of individuals, or with an unsatisfactory con- struction or arrangement of the tests. A variation 28 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES of two years and more must point to inherent defects in the scale, or fundamental abnormalities or depart- ures in the mental organization of the subjects tested. (6) Finally, so far as concerns our fundamental query, it is possible that both the wide-range method of testing and the method of grading may partly account for our skewed epileptic curve. For exam- ple, the A-method of scoring decreased the per cent, of IX-year-olds about 6.5% and increased the num- ber of X- (particularly) and the number of XIII- year-olds, as may be seen from Table II. Likewise, it is seen from Table III that, while 90% of those grading IX passed this standard by virtue of ad- vance credits, 94% of those who grade X passed the tests of that age. Accordingly, the skew in the curve at X and this is the most obvious skew is inde- pendent of the method of scoring. So far as con- cerns our present purpose, the method of scoring may, therefore, probably be neglected, more particu- larly because it has conformed with the prevailing usage, thus rendering the results comparable with the findings of other investigators. Consequently it will be necessary to study more closely the wide- range method of testing. TESTING THE BINET-SIMON TESTS 29 to? HH Sfg, . a> n * *'l- J-H O O - rf* ^ 1x5 tO Ol t^ CO . "* >- l- O C5 frlf ? as ?i "" s* * ~ 3 s.< -s. rs tt C5 *. *-:i a 5T s S a. 53 . ^ M I SO 1-1 Is- 2^^888 - !_>_>_>! g. C^ MMOh*OCO f a 828888 ~ MMMM f 8^8388 ^ y. S- * S: sr S. o o a. 30 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES The importance of this factor may be seen by re- ferring to Table III, which shows that in not more than five ages (III, IV, X, XII, XIII) did more than 60% of the patients successfully pass the ages in which they classify. The ages which make the worst showing are VI, VII and IX, particularly VI and IX, which proved veritable ponies asinorum. It follows that the age classification of the majority of the epi- leptics was attained on the basis of advance points. Very few, except in Age X, passed all but one of the tests of the mental age assigned them. It is therefore apparent that any B.-S. testing which is confined to the subject's chronological age or to the age immedi- ately above or below is of questionable value, if not worthless, and is positively pernicious to the inter- ests of scientific research either for purposes of diagnosis or classification or the testing of the scale. To what extent, then, is the wide-range testing responsible for our peculiar curve of distribution I Owing to the present inaccessibility of the original records, I cannot answer this question in exact numerical terms. But the two following considera- tions would seem to indicate that the method of test- ing is of secondary consequence. First, it is probable that other examiners (particu- larly the Vineland workers, with whose results our curve has been contrasted) have made a practice of testing the mentality of the examinees at least two years above the station in which they grade (since the basis of rating has been uniformly the highest age passed, the testing of lower ages can be entirely ignored). In case this is granted other writers have been silent on this point the fundamental question reduces merely to one of the relative TESTING THE BINET-SIMON TESTS 31 amount of the advance credits given the difference in the number of credits which may be gained by testing only two years above the age fully passed or by testing in a considerable number of ages. While we have found numerous epileptics whose capacities have ranged throughout the larger part of the scale, the successes higher up have usually been sporadic and exceptional, so that it is entirely probable that the great majority of the advance credits given the epileptics have come from the tico adjacent higher ages. If this is so, the peculiarities in the curve can- not be due primarily to the wide-range testing. Second, while the system of advance crediting from a wide-range testing effectually conceals the skew which should have appeared in the curve at Age VI, it is only very slightly responsible for the skew at Age X, because 94% of those who grade X pass the standard for this age, while 84% of them fail on the IX-year tests. Not only so ; an examina- tion of the feeble-minded classification shows that the most obvious break occurs in the ninth standard. It is thus apparent that if further analysis reveals other significant factors, as implied in the foregoing statements, the methods of scoring and wide-range testing must be given a subordinate place. There are three methods which we may employ for a fur- ther critical examination of the data: TABLE IV. Percentage of Epileptic Children Passing Each Individual fiinct-Simon Test, irrctfective of the Age in tohtck the ChOdri-n arc Classified 1 11 100 2 11 90 3 11 81 4 12 41 5 9 33 12 58 7 17 61 8 15 33 9 18 66 10 60 90 11 60 91 12 23 69 13 23 65 14 29 83 15 20 73 16 25 64 17 21 62 18 52 CO 19 43 88 27 39 28 36 29 28 30 45 31 47 32 48 33 36 34 46 35 47 36 47 37 51 38 39 39 45 40 38 41 47 42 45 47 45 48 49 49 40 50 44 , Girls . , Both Sexes-^ Avt. Av< No. % Range. No. % Hang 7 85 18 94 6 66 17 82 6 50 35 17 70 24 7 57 19 47 6 00 15 20 6 83 S3 18 66 46 14 78 31 70 17 64 32 50 17 82 35 74 40 95 100 92 42 97 33 102 94 44 18 83 41 75 19 68 42 66 28 71 57 77 19 68 15 39 71 11 25 68 50 66 24 70 45 66 37 51 80 56 35 91 40 78 89 33 30 70 56 67 38 10 81 10 31 58 58 59 36 63 S3 72 29 51 5 69 75 irl 55 ai 80 67 43 33 59 80 C>6 34 44 81 56 37 04 88 60 29 34 68 45 30 60 75 54 28 57 30 66 66 21 36 38 83 53 36 55 81 70 29 17 73 33 : 10 75 14 30 10 77 23 2! 20 45 74 31 56 31 48 76 49 35 48 84 66 29 34 69 45 29 34 14 73 36 30 19 21 52 30 21 33 54 40 26 19 65 13 17 23 50 16 15 06 27 44 11 29 23 17 54 07 19 Tit 53 59 20 00 53 02 14 14 57 44 18 57 14 14 43 29 11 18 40 12 o 00 18 22 00 29 38 37 r Aves., Each Ago.--, Both Boys. Girls. Sexes. 33 36 33 42 39 10 33 12 29 14 59 30 20 61 XIII. 60 29 34 61 29 10 62 17 00 34 Ave 39 B.-S. Test : the tests arc numbered consecutively, following the customary order (See Form I of the Skillman blanks). No.=niimber tested. %=\K"c cent, of successes. Kange^difference between the highest and lowest per cents, in each age. Aves. for each age represent the *um of all the tests in each age, divided by the number of tests. The above includes all the epileptic children except nine. It includes four boys who had been free from attacks for over two years. TESTING THE BINET-SIMON TESTS 33 (1) We may determine the percentage of suc- cesses (passing) for each individual test of the entire scale for a given group of examinees, irrespective of the ages in which the examinees classify. Such a tabulation for all the epileptic children (all under 21) appears in Table IV. The records for the adults are not now available, but the curves for the children and the adults, in spite of various interesting differ- ences, have the same general characteristics (Table I). As will be seen from Columns 2 and 5, Table IV, the number of children put through each test differs considerably, but the percentages of successes are in all cases based upon the number examined for the given test. (2) We may determine the per cent, of successes in each individual test, based only on the records of those subjects who classify in the age to which the test has been assigned. That is to say, we determine what percentage of patients who grade VI pass each one of the Vl-year tests, what per cent, of the VII- year-olds pass each of the eight tests of that age, etc. With this object in view, the data for the children have been retabulated in Table V. If the tests in each age are relatively equi-difficult, the successes should be approximately equal for the different tests of the same age. This method could be extended so as to include a determination of the per cent, of suc- cesses for each test in both lower and higher ages. What per cent, of subjects who grade V, VI or VII pass each of the tests in Age III or IV T 34 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES TABLE V. Percentages of Children Passing the Individual Tests in the Binet-Simon Ages in which then ore Graded. AGES I AND II. Both , Bovs -. - Girls N Sexes. AGE III. Both , Bovs v , Girls \ Sexes. Test. No. y VIII, VII and V (decreasing order). This conforms substantially with the data in Tables V and VII, to which we now turn. The latter enable us to make a more reliable com- parison between the difficulties of the different tests of the same age, and indirectly between the relative collective difficulty of the different ages, for here, as explained, the per cents, of successes for a given test are based on the testing of those subjects only who classify in the age in which the test has been placed. The variation between the different tests of the same age appears most readily from an examination of the M. V. and " range" columns. The average M. V. for all ages amounts to .17, a very considerable fraction of the size of the average per cents. (.61). It is practically the same for the boys and the girls, although there is considerable difference in a few of the ages. TESTING THE BINET-SIMON TESTS 39 TABLE VII. Ranges beticzen the Highest and the Lowest per cents, of successes recorded for the tests of each Age in Table V. Ages I & II. III. IV. V. VI. VII. VIII. IX. X. XI. XII. XIII. Boys 72 100 40 100 72 60 66 84 32 33 00 50 Girls 100 67 72 50 66 84 67 100 12 100 100 Children . 78 74 45 33 70 73 40 89 16 50 33 The general averages for all Ages, except XIII, are as follows: boys, 60% ; girls, 74% ; both sexes, 54%. The M. V. amounts to more than .25 in seven cases : Ages I-II, boys and girls; III, boys; VII, girls; IX, boys and girls; and XII, girls (exclusive of Age V, boys). The ranges (Table VII) are also very large for these ages, the seven largest ranges being in Ages I-II, boys; III, boys; VII, girls; IX, boys and girls; XI, girls; and XII, girls. Five of these amount to 1.00 and two to .84. The average of the ranges for the years I to XII, inclusive, reaches the very considerable sum of .54. It is somewhat larger for the girls than the boys. On the other hand, considering the minimal varia- tions, we find the M. V. to be less than .17 in the fol- lowing ages : III, girls ; IV, boys ; VI, boys and girls ; VIII, boys and girls; X, boys and girls; XII, boys. In some of these ages we also find, correspondingly, the smallest ranges, namely, Ages IV, boys; X, boys and girls; XI, boys; XII, boys and girls. The smallest range comes in Age X. If we consider only the general averages (the av- erages for the two sexes), the largest M. T-Vx (from .20 to .28) are in the following ages: I-II, III, VI I and IX, and the largest ranges in Ages I-II, III, VII and IX. The smallest M. V.'s (from .14 to .05) are in the following ages: V, VI, VIII, X, XI and XII, 40 EXPERIMENTAL STUDIES OP MENTAL DEFECTIVES and the smallest ranges in the following: V, VIII, X and XH. Summarizing these results, it appears that, if we exclude Ages 1-11 as representing two years rather than one, the greatest variation occurs between the tests of Ages III, VII, and particularly IX, and that the greatest uniformity obtains in VIII, X (dis- tinctly), XI and XII (less decidedly in IV and VI). The question now naturally arises whether the collective difficulty (average per cent, of successes for all the tests of a given age) is greatest for the most variable age-norms. Reference may be made to three tables to obtain light on this question. On the basis of the average per cents, in Table V, there appears to be no correlation. The group average for Ages III, VII and IX is .64 (.66 for boys and .59 for girls), and for Ages X, XI, XH, IV and VI .61 (prac- tically the same for the boys and the girls). The per cents, in Table V, however, do not represent the number of patients who passed the age-norms, as in Table III. In the latter table the successes (32%) for the group of variable age-norms are appreciably less than for the group with more uniform tests (49%). It is noteworthy that the successes are above 63% in three ages (IV, X and XII) where the varia- tion is small, and in only one age where the variation is large (Age III), and that the successes are sur- prisingly small in the remaining two ages having unequal tests (VII and IX. Cf. also Table VI). In the case of Age VI, however, the variation is small, although this is a very difficult age (Tables III and VI). It is therefore apparent that there is a greater variation between the tests of a difficult than an easy TESTING THE BINET-SIMON TESTS 41 age-standard, although this need not always be so. If the tests of a given age are uniformly difficult, the variation will be small, and the same is true, of course, if they are uniformly easy. But they are more liable to be uniformly easy than uniformly difficult. The most striking result which our analysis of the M. V.'s and ranges for the ages has thus far shown is the amazing lack of uniformity between the diffi- culty of the tests of the same age-norms for fully half of the ages of the scale amazing from the standpoint of the precision demanded by the stand- ards of scientific work. Moreover, we have also seen that the collective difficulty of different age-stand- ards differs to how great an extent may be seen by a re-examination of Tables III and VI. The per cents, of passing range from .00 to 100%. (The lat- ter may be ignored, as it is for the final age in the scale, and all who passed this standard could only do so by virtue of the tests of this standard itself). The successes exceed 70% in only four ages (III, IV, X and XIII), and reach less than 42% in six ages (V, VI, VII, VIII, IX and XI). The most difficult age-norms are VI (00% of passing), IX (10%) and VII (13%); and the easiest III (.73%), X (84%), X/7 (58%), and XIII (100%). The last age may be neglected for the reason given, and III and XII be- cause of the fewness of the subject tested in these ages. We thus obtain for epileptics one specially easy age-standard, X, and several specially difficult age-standards. In order to study more thoroughly the two most difficult ages, VI and IX, the data for the juvenile and adult epileptics were retabulated as appears in Table VI (which see). 42 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES With this surprisingly wide range in the difficulty of the Binet-Simon age-norms demonstrated, we are forced to meet a fundamental question, namely: In order that a measuring scale of intelligence shall approximate the character of scientific measures, what amount of variation in the difficulty of the tests of the same age shall be considered as the maximal permissible? What percentage of normal children should pass the tests designated as criteria of their chronological ages in order that the tests shall con- stitute scientific standards for these ages? It is evi- dent that if only a small per cent, of typical children pass the standard tests the latter are worthless. It is equally evident that 100% of passing is also out of the question, because normal children will differ considerably in various traits and capacities, some being strong in one trait and some strong in another. We may thus regard as perfectly normal a certain amount of variation in the capacities of children of the same ages and training. Moreover, mental meas- urements are variables, and not absolute constants. Consequently the standards of each age must consist of a number of tests, sufficiently comprehensive to survey a variety of fundamental mental traits and capacities. And the difficulty of these tests (and the scoring) must be so adjusted that, while one test may be too hard for one child and another too easy, the majority of children should be able to pass the collective standard, i. e., their age-norm. To be more specific, I should hold that if 75% of normal (so- called) children fail to pass their age-norms, the norms are too difficult. Some of the tests must be transposed or eliminated. On the basis of this standard, it appears that only TESTING THE BINET-SIMON TESTS 43 two age-norms are properly constructed, so far as the testing of the epileptics is concerned, namely, III and X (Age IV falls short by 4%). Half of the ages do not even approximately satisfy the require- ments. In fact, we may lay down this rule: that epileptics do not qualify for a given age on the basis of satisfying the requirements of that age, but on the basis of the system of advance credits from higher ages. To what, then, are the demon strably large varia- tions in the difficulty of the various Binet-Simon age- norms due! Are they due primarily to inherent de- fects in, and misplacements of, the tests themselves defective horizontal and vertical arrangement or to fundamental deviations or abnormalities in the epileptic mind? To answer this question satisfac- torily we must still ascertain what particular tests produced the greatest 'mortality' were too difficult and what particular tests were too easy. More than that, we must determine whether the tests found too difficult or too easy for epileptics have likewise been found too difficult or too easy for normal children or normal adults. A comparison of Tables IV and V (omitting Ages I, II and XIII, on account of the insufficiency of the data) indicates that the following tests were dis- tinctly too difficult for epileptics : Age V, arranging triangular pieces into a rec- tangle; 1 VI, repeating 16 syllables, 2 executing three commissions, and knowledge of own age; VII, re- peating five numbers, drawing a diamond, and de- 'The success for this test is high in Table IV, because it was given to an unusually large number of high-grade subjects. 'Namely : "We get up in the morning, eat, work and play, and then go to bed." (Variant forms infrequently employed.) 44 EXPERIMENTAL STUDIES OP MENTAL DEFECTIVES scribing actions ; VIII, counting backward and copy- ing from dictation ; IX, descriptive or classificatory definition, six memories, giving correct change (25c. 9, or 8 or 7c.), and arranging six weights ; XI, arranging shuffled words into a sentence, essential ideas in abstract definitions, and uttering 60 words ; XII, repeating 26 syllables, 1 and inferring facts from given circumstances ; and XIII, all tests. In all ex- cept one of the above tests the per cent, of successes is less than 50 ; in most of them decidedly less. The failures for the higher ages are not brought out properly in the tables because of the form of the tab- ulation and because of the fewness of the subjects tested. While the tables are not so constructed as to indi- cate which tests are too easy (passed in lower ages), I came to feel that the following should probably be so regarded : Age V, counting 4 pennies ; VII, num- ber of fingers on hands, and counting 13 pennies ; IX, naming days of week in order ; X, naming moneys ; and XII, giving rhymes. Since the above was written, the results of Kath- erine Johnston's, 2 Goddard's 3 and Bobertag's 4 test- ing of public-school children have, opportunely, ap- "The other day I saw in the street a pretty dog who car- ried in his mouth a basket of strawberries." (No variants used.) 2 Katherine L. Johnston, M. Binet's Method for the Measurement of Intelligence. Some Results, The Journal of Experimental Pedagogy, 1 : 1911, 24ff. "Henry Herbert Goddard, Two Thousand Normal Children Meas- ured by the Binet Measuring Scale of Intelligence, Pedagogical Semi- nary, 18 : 1911, p. 232f. *Otto Bobertag, Ueber Intelligenzpriifungen (nach der Methode von Binet und Simon), Zeitsch. filr angewandte Psychologic, 5: 1911, lOoff. TESTING THE BINET-SIMON TESTS 45 peared. These, with other results already available, 1 will better enable us to explain the inequalities which we have found in the scale. Miss Johnston tested a mixed group of 193 ele- mentary, and 25 high-school girls in Sheffield, Eng- land; Goddard's assistants tested the entire school population (1547) of the first six grades of a New Jersey school system, and Bobertag tested 435 regu- lar and special pupils in the schools of Breslau. The former followed essentially Binet's latest (1911) revision, while Goddard, Bobertag (with certain ex- ceptions) and I followed the 1908 series. All three of these studies confirm some of my sus- picions with respect to the accuracy of the scale. Johnston refers to one girl who did 15 and another 23 tests superior to the age in which she classified, but she does not give averages, nor any intimation as to how frequently this happened. It is, as we have seen, a frequent phenomenon among epilep- tics. We need to know to what extent it appears with normals before we can generalize unequivocally about abnormals. She, too, found pupils who, unable to satisfy an inferior age standard, passed higher 'The following studies or discussions have appeared too late to re- ceive notice in the present discussion : J. C. Bell. Recent Literature on the Binet Tests, The Journal of Educational Psychology, 3: 1912, 101 ff. Lewis M. Terman and II. G. Childs. A Tentative Revision and Extension of the Binet-Simon Measuring Scale of Intelligence, The Journal of Educational Psychology, 3: 1912, 01 ff, 133ff, 198ff. Edmund B. Iluey. The Present Status of the Binet Scale of Tests for the Measurement of Intelligence, Psychological Bulletin, 9 : 1912, 100 (a review of the literature). F. Kuhlmann. The Present Status of the Binet and Simon Tests of the Intelligence of Children, Journal of Psycho-Asthenia, 10: 1912, No. 3. An abridged discussion of the relevancy of the scale will be found in : J. E. Wallace Wallin. The Present Status of the Binet-Simon Graded Tests of Intelligence, The Alienist and Neurologist, 33: 1912, May. 46 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES ones, but no figures are given to show how frequently this happened. She also found obvious inequalities in the difficulty of the age-norms. Her records show that of 30 9-year-old girls only one satisfied the IX- year norm, as against 24 who failed and 5 who passed Age X. Of 41 7-year-olds, 6 passed their standard, as against 26 who failed and 9 who passed Age VIII. Of 22 8-year-olds, 7 passed, 15 failed and 6 "went above" VIII. Of 38 10-year-olds, 12 passed and 26 failed. Of 24 12-year-olds, 5 pased, 18 failed and one passed Age XV. These figures indicate that there is a wide divergence in the difficulty of the tests of the same age, and that, with normal (sic) English girls, the standards are too difficult, as a rule: there are more who fail than reach their age- norms. The most difficult age-norm, according to Miss Johnston, was Age IX. These conclusions, it must be remembered, refer to the latest, or 1911, ar- rangement of the B.-S. tests. An examination of Goddard's table (Table I) shows that there were more 6-year-olds who could satisfy the VII- than the Vl-year norms (69 against 48) ; that a larger number of 8-year-olds stayed in Age VII than passed Age VIII (87 vs. 86) ; that very few of the 8-year-olds were able to satisfy the IX-year tests (only 16, as against 86 for the VIII- year norms), but there were actually more 9-year- olds who could pass the X- than the IX-year norms (58 compared with 56); that an unusually large number of 10-year-olds qualified for their standard, while an appreciably smaller percentage of 11-year- olds qualified for the Xl-year standard; and that more 12-year-olds classified as X than as XII (42 vs. 39). The results of both of these studies of pub- TESTING THE BINET-SIMON TESTS 47 lie school children (Bobertag gives results only for the individual tests) accordingly confirm my find- ings, based only on the results of those epileptics who grade in the various Binet-Simon ages consid- ered, particularly in respect to the disproportionate difficulty of Ages VI and IX and the dispropor- tionate ease of Age X (Miss Johnston's data, it should be said, to avert misapprehension, are based on too few cases for Age VI). It is obvious that we must conclude that there is a faulty vertical arrange- ment of the tests in the scale as at present consti- tuted. No only so : our findings in respect to the individ- ual tests are also confirmed, at least in part, as shown in Table VIII for the tests which I came to view with most suspicion. In this table the conclusions of Decroly and Degand, Binet's 1911 revision, and Johnston's, Goddard's, Bobertag 's and my own find- ings are compared. The Skillman figures are based on Table V. Table VIII may thus advantageously be studied with respect to our fundamental inquiry : Does the testing of normal (so-called) children show that our anomalous results are due to defects in the construction of the scale or to the peculiar mental organization of the epileptic! A study of Table VIII shows, in harmony with our findings, that the following tests (with certain obvi- ous discrepancies) are too difficult: Age V: rear- ranging triangles, by G. (Goddard) and Bo. (Bober- tag). B. (Binet) retains the test, however, in Age V. VI: repeating 16 syllables, by G. (15% of successes). B. omits the test. VII: repetition of five numbers, by J. (Johnston) and B., who elevates the test to Age VIII, as does G., though his own per cent, of sue- 48 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES cesses in VII (74%) indicates that it is about right where it is. Bo. finds it properly placed. VIII: copying dictation, by G. ; B., sustaining D.-D.'s (De- croly and Degand) objection (training test), omits it, but Bo. finds it rightly placed. IX : giving correct change, by G. and J., but not by Bo. (who used 100 20 = 80) . Definition by description, by J. and G. Arranging six weights, by J. and Bo., and ap- parently by B., who places it in X, while D.-D. would place it in V or VI. XII : repetition of 26 syllables, by J., G. and B., but too easy by Bo. if the sentence is simple and meaningful. XIII : all tests, by all. TESTING THE BINET-SIMON TESTS 5 B- SB CD *a is -. .1 %% K P D g. i*i. E Q |S*8 3 c-o- 5'5'S -13 n. "5 E 5 D 3 H 9 n a> ~ definitions ;ing sbufiQe g weights, moneys v-4 g-3 a B gS IPS ~ . &: i 8 | DD *5 3 i ^ . 5": o >- ct B i !?:- 00 (Or* : : ea . . Bp o.: o : : : 2 !HW " C.B 1 - &* 2. 2- 5-5-1 5" p triCRX gq o 2.2-3 2.B 2 2 3 3 g 3 3 5 S.g 3 B .3 ~- ~-- _ ^- n- S'S'o ?S" (tiro JtS O-^W^^d^'tOOlH - OiUlSotO^2S 1 * * r^ " _^ o * 2 ^ ^% - S T ^"1 4 T T ^ r- ^ *J ^* o o oo o ?5"*""< 5^t8 u: "o 83*lS5 ks ' M S u S8 JSSSr: ? HO H H ^H H ^? 8 8 8 E-8 8 So? SS^'S^ iiSggSJSg^SSlg S^|e| 50 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES The following tests, contrariwise, proved to be too easy, in harmony with my results : VII : counting 13 pennies, by B., Bo. and G. D.-D. object to the test as too mechanical. YIII : naming four colors, by D.-D., B. and G. (Our VII- and VEII-year-old epileptics required 7.7 seconds, and IX-year-olds 5 seconds, to name the colors.) X: naming money, by Bo., B., who has dropped it to IX, and perhaps by G., who finds 70% of successes in IX, but retains it in X. J., however, found it too hard. XII : three rhymes, by G., but not by Bo., nor by B., who has raised it to XV ( !) . Counting four pennies in V, which appeared to Bo. and myself too easy, G. and B. found about right, while D.-D. would discard it as a training test. The following tests, which I found too hard, would appear to be properly placed: VII: describing ac- tions, by B. and G. VIII : counting from 20 to 0, by B., Bo. and G. (considered a training test by D.-D.). IX: 6 memories by Bo. and G., but too hard by J. B. omits it on D.-D.'s objection (training). (Our IX-year-old epileptics average 4.8 memories ; our X- year-olds, 5.3, and our Xl-year-olds, 6.5). In respect to the following tests the discrepancies are more patent than in any of the above tests : VI : three commissions, found to be properly placed by G., too easy by D.-D. and Bo., and too hard by B. and myself. VI : giving own age, distinctly too hard for epileptics, considered valueless by Bo., omitted by B., and considered a training test by D.-D. XI : ut- tering 60 words, too easy by D.-D., too hard by Bo., right for Age XII by J. and B., and for XI by G., and too hard for epileptics (about right for Age XII, where the average number of words was 59.9). XI: abstract definitions (justice, charity, kindness, used TESTING THE BINET-SIMON TESTS 51 at Skillman), right for Age XII by B. and Bo., too hard for XII by J., slightly too hard for XI by G., and distinctly too hard for XI for epileptics. XI: rearranging words, right for XII by B. and Bo., and for XI by G., too hard for XII by J., and distinctly too hard for epileptics of Age XI. Having thus surveyed the available facts, we are now in a position to formulate a number of impor- tant conclusions. (1) The marked irregularities in our curve of intelligence for epileptics are partly explained by the system of advance scoring from a method of wide-range testing, and by the method of combining the records of a large number of adult epileptics and a smaller number of juvenile epileptics (the propor- tion of the adults among the epileptics being larger than among the feeble-minded, as we have already seen). It might be assumed that the latter circum- stance to which we have merely adverted in the foregoing pages would render the curve more or less irregular, for a defective child and a defective adult whose intellectual strength or capacity are the same, would not necessarily test out exactly the same by the B.-S. scale as at present constituted. We have, indeed, already noted here and there various differences between the children and the adults (others will be noted in the following chapter), and have found evidences of the loss of lower-age capaci- ties among the adults. To measure the influence of this factor, however, it is necessary to examine the table of distribution (Table I), and particularly the table which shows the number of higher-grade sub- 52 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES jects who pass especially the crucial ages, Ages VI and IX (Table VI). In the first table it is seen that, while there are about 3% more children than adults grading VI years, the number of IX-year-olds is approximately the same. The number of imbeciles among the chil- dren, however, is considerably higher than among the adults, while the number of morons and XIII- year-olds is noticeably less. In Table VI it is seen that of those testing from IX to XIII years, 22% of the children pass the IX-year tests, but only 5% of the adults (the differences for Ages X, XI, XII and XIII are also large, due possibly to the small num- ber of patients in some of these ages), while of those testing from VI to X, none of the children passes Age VI, as against 11% of the adults (with large differences also for Ages VII to X). While it is thus evident that an adventitious factor of this character the averaging of the gradings of defective children and adults will distort the sym- metry of the frequency curve, an examination of the separate columns for children and adults in Table I shows that skews are present in the classifications of each, particularly at Ages IX and X, only less prominently for the children than for the adults. Hence, we appear to be justified in the conclusion that the distortions in our curve are not primarily caused by the method of advance scoring from wide- range testing or by the merging of the grades of young and old defectives. (2) On the other hand, one of the significant causes of our skewed curve (skewed certainly as compared with the curve for feeble-mindedness) is the intrinsic defectiveness of the measuring scale, TESTING THE BINET-SIMON TESTS 53 for our analysis has demonstrated that there is a greater discrepancy in the B.-S. 1908 scale (and 1911 scale so far as Johnston's results indicate) than has hitherto been conceded or suspected. Its obvious inequalities affect not only some of the individual tests in various levels, but also the age-standards. Just how much of the irregularities can be ascribed to the defects in the scale it is impossible to deter- mine with definiteness until a re-examination of epi- leptics has been made by a scale rendered maximally correct and standardized for "typical" American children. (3) It is, however, not only probable, but reason- ably certain, that the combined influences of the fore- going factors does not suffice fully to explain our curve. Three affirmative reasons may be given why another factor, namely, the peculiar mental make-up of the epileptic, must be considered. First, an in- spection of Table VIII shows that the percentage of failures on the difficult tests is abnormally large for the epileptics, in nearly every case very much larger than for the normal groups, so that the correspond- ing traits in the epileptics have at least suffered marked impairment. Second, some of the tests ab- normally difficult for the epileptics do not always prove difficult for the normals. Third, failures on some of the tests through various levels imply an impairment of the same or related functions. Thus, the epileptics suffer from a fundamental impairment of memory, as shown by consistent failures in all the tests of memory span (sentence and number tests), by the inability to reproduce six units from reading a short passage once, by the inability to recall their ages, and to remember and execute three simple com- 54 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES missions. They are also markedly retarded or feeble in the higher thought processes, the rational functions brought into play in the more intellectual tests and in the tests calling for an adjustment to new situations. This is shown by the incapacity to form a rectangle from two triangular pieces, to exe- cute a triple order, to construct an intelligible sen- tence from displaced words, to give descriptive or classificatory definitions of common objects or ab- stract definitions of simple qualities, or to infer facts from given situations (the situations employed in the test, it may be conceded, do not well fit American conditions), or to utter 60 words in three minutes. The epileptics suffer from a pronounced retardation of rate in the stream of thought and of motor re- sponse. They apparently also suffer from a blunt- ing of the kinesthetic sensitivity: the threshold of sensory discrimination for lifted weights is abnor- mally lowered. To carry the analysis further, how- ever, is not advisable until the scale has been more accurately ' ' calibrated. ' ' When this has been done, its value for individual mental diagnosis will be greatly enhanced. While, therefore, the peculiarities in our curve can be partly ascribed to extraneous circumstances and to imperfections in the scale, they also implicate in- herent anomalies in the mentation of the epileptic. In fact, our B.-S. testing has furnished us with a picture of the results of a process of mental wreck- age caused by pathological processes going on in the afflicted individual or by a neuropathic heredity, whereby the integrity of various mental functions has been impaired at various levels of mental devel- opment, or whereby certain lower levels of mental TESTING THE BINET-SIMON TESTS 55 functioning have been swept away, while higher levels have remained intact mental sentinels that have remained to tell the story of destruction. This interesting clinical picture of mental ruin and havoc is still incomplete in its finer delineations and invites further psycho-clinical research. (4) Finally, the facts brought to view above should make it patent that the B.-S. scale is still in its experimental stages a fact that should occasion no surprise when we consider the short time that it has been in use, particularly in this country. It still requires a thoroughgoing tryout and revision. Re- visions have, indeed, already been attempted by Binet and Goddard. In some respects their changes harmonize with the requirements of our comparative table (Table VII), but in other respects not. In this table only the tests most obviously misplaced for epileptics have been compared with normal perform- ances.) Since there is considerable disagreement in the conclusions of the five writers who have worked with normals in France, Belgium, Germany, Eng- land and the United States, it is obvious that the question cannot be considered closed. American in- vestigators will have to establish norms for Ameri- can children. The studies already made sufficiently indicate that a test too difficult for children of one nationality may be too easy for those of another. For American workers Goddard 's results, based as they are upon an extensive testing of American chil- dren, are the most suggestive. But it appears to me wise to continue the use of the 1908 scale until more returns are in until we have tested large masses of boys and girls by the wide-range testing to which I have already alluded. It is questionable whether we 56 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES can calibrate and improve the scale by confining the testing to a very limited range of years. [Obviously, this work will require the earnest cooperation of many psycho-clinicists. More than that, it ought to receive the undivided time and attention of child study specialists of a worker or group of workers who can devote themselves to this particular service as a life career. In my judgment, this work can probably not be done effectively and within a reasonable time unless it is established as an independent department of research. The clerical labor connected with investi- gations such as this is so onerous that it should be cared for by a force of clerical assistants. At the present time all, except possibly one, of the psycho-clinical investigators are swamped with purely clerical work (computing, tabulating, etc.), and must use up their best energies in purely routine and mechanical labor. This is uneconomical from the standpoint of public finance and the conservation of the nation's best creative brain power.] The further improvement of the scale, we may add, requires the transposition of certain tests, the elimination of certain others which seem valueless, the equalization of the number in each age or the proper differential adjustment of the system of ac- crediting points, and the increase rather than the decrease of the number of tests for each age. I feel that the last point requires emphasis. We need to probe a considerable number of traits and capacities for the reason given (p. 42) if we would arrive at a true clinical picture of the child or a correct classifi- cation. We cannot hope to diagnose or grade accu- rately if we test only a few capacities, or if we base our judgments on only a few symptoms. The ele- ment of variation in human traits is too large. What is needed is a well-balanced, comprehensive survey of the fundamental human mental capacities. The minimal number of tests for each age should be placed, I believe, at ten. I should regard it as unfor- tunate to eliminate such tests as the age, writing and reading tests. All of these have furnished important information with respect to the epileptic (as well as TESTING THE BINET-SIMON TESTS 57 various types of insane patients recently tested). Nor is it essential to eliminate all the tests which are dependent upon training (or, indeed, all which are pedagogical), partly because this is not desirable and partly because this is impossible. Nature and nurture proceed hand in hand, inseparable, recipro- cal, interacting and independent only in conception. Just as we posit a normal rate of development which the forces of human nature undergo normal, that is, within limits so we may posit a normal curve of development within variable limits for a given order of civilization or social evolution, which human changes follow as a result of the processes of nur- ture. We cannot, if we would, test merely pure na- tive capacity uninfluenced by environmental agen- cies, except possibly during the first months of life. But we can measure native capacity as modified by the environment. In this country, where we have fairly uniform standards of educational require- ments in the schools, there would seem little rea- son for eliminating some of the more funda- mental academic tests. A child of eight or nine who cannot read at all certainly demonstrates his intel- lectual inferiority thereby. To repeat: The evidence regarding the imperfec- tions in the Binet-Simon measuring scale of intelli- gence cannot be brushed aside. The scale certainly has not yet been made maximally accurate or scien- tifically precise scientifically precise in the Aris- totelian sense (we may demand only that degree of accuracy in a given subject of inquiry which the sub- ject-matter itself allows) or sufficiently standardized. A large work and a challenge remain for the students of ' Intelligenzpriifung" -a work that will pay 58 double interest on a large investment of time and labor, for the public schools, juvenile courts and in- stitutions for defectives stand in dire need of a sim- ple, objective, practical mental measuring rod by which to determine the degree of mental arrest, de- fect or acceleration of deviating individuals, and by which properly to classify institutional cases. In the light of the defects which we have found in the scale, what, then, shall we say of the value of the B.-S. system of classifying defectives? An answer to this question must await the analysis of the fol- lowing chapter. CHAPTER III. THE VARIATION OF MENTAL AND PHYSICAL, TRAITS IN RELATION TO THE AGE CLASSIFICATION OF THE BINET-SIMON SCALE. Paidologists have been wont to accept the postu- late that mental traits or capacities increase in effi- ciency or multiply in number with increasing age. The validity of the B.-S. scale itself depends on the validity of this assumption. If we accept the as- sumption as correct, the following conclusions follow : First, it is feasible to construct a graded scale of mental performances consisting of a series of tests which either progressively increase in difficulty from year to year (similar tests being repeated at various levels) or measure new traits developing at various higher levels. Second, it should be possible to arrange these tests in a fairly accurate ascending age series, so that we can locate the mental station of normal and ab- normal individuals in units of mental age, and deter- mine how any mental or physical characteristics vary in accordance with a fixed classificatory or graded scheme. Third, by plotting age-curves for the individual traits tested in the scale (as well as for functions tested independently of the scale), we secure a means 59 60 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES of trying out the accuracy of the scale itself and of determining more fully to what extent these traits vary with age among normal and abnormal indi- viduals. In this chapter I shall be concerned with this third conclusion, because the imperfections revealed in the 1908 B.-S. scale by the data considered in Chapter II naturally raise the question whether or not the scale is of any practical value in the mental grading or diag- nosis of normal or abnormal subjects. // it can be shown that the AVERAGE EFFICIENCY in the various traits tested increases with growing age (annually or biennially), then the scale, in spite of its imperfec- tions, and provided the mean variations in each age are not too large, remains a valuable means of deter- mining, in comparable terms, the classification of DIFFERENT HOMOGENEOUS groups of persons. For if the individuals were very poorly classified, we should expect to find obvious irregularities or skews in the curve of efficiencies for each trait, and extreme mean variations. Of course, the relevancy of the scale, even if it be imperfect, for determining the relative station of different individuals in the same homoge- neous group, needs no argument. The discussion of the scale will also serve to bring to view various facts of considerable interest re- specting the mental efficiencies of epileptics. In order satisfactorily to analyze our data it will be necessary to examine the averages for the entire population, of all ages and both sexes, in the various tables, and the corresponding mean vari- ations. The former will be examined with consider- able thoroughness, the latter more briefly. Finally, VARIATION OP MENTAL AND PHYSICAL TRAITS 61 a concluding section will be devoted to the more general conclusions and comparisons. It is unfortunate that, in the absence of the origi- nal data, it will be necessary to limit this study to four B.-S. tests, and to tests with the form-board, dynamometer and ataxiagraph. EXPLANATION OF TESTS. In the color test (Table X) the patients (224 epi- leptics between the B.-S. ages III and XIII) were uniformly, with few exceptions, instructed to name the four colors as rapidly as possible. The experi- menter pointed to each color in succession rapidly, so that the results would represent maximal per- formances were it not for the fact that the green used in the testing of about one-half of the patients was poorly saturated, and therefore caused hesitation or failures. Green, even at its best, is the least fre- quently named of these colors, among normal per- sons, as appears in Bobertag's B.-S. testing of Ger- man children, while red is the most frequently named. Blue and yellow were about equally difficult. The following was found by Winch to be the order of the correct application of color names among children three to five years of age: black, white, red, blue, green, yellow, violet and orange. The order agrees with Bobertag's, except that green is placed ahead of yellow. In my testing of epileptics no other single color caused so many delays, indecisions or failures as green. I agree fully with Bobertag that these colors, in order to serve a useful purpose in the scale, should be standardized. In the test of uttering discrete words the subjects were always told to utter just as many single words 62 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES as possible during three minutes or until told to stop (Table XV). Those who were slow were usually incited to greater effort by verbal suggestions. Three or four examples, illustrative of the object of the test, were furnished at the outset. No record was included which consisted merely of phrases or sen- tences or which consisted of any considerable num- ber of these, and none was excluded because of pecu- liarities in the word lists (such as uttering many numbers unless, indeed, all the words were num- bers or letters of the alphabet, or names of months or days). In the reading test (Tables XI and XVII) the fol- lowing selection was used : Three | houses | on | fire. New York, | September 5th. | A fire I last night | destroyed | (three houses) in the center of the citj. | Seventeen | families | are without homes. | The loss is more than | thirty thousand dollars. | In saving | a child | who was asleep in bed, | one of the firemen | was badly | burned | on the hands and arms. | (The units are indicated by the line divisions. In a few cases half credits were given ; e. g., half a memory for "September," "on the hands," "thirty thousand.") The subjects were merely told to read the selec- tion, without intimation that they would be expected to reproduce it. To many this test was given after some of the speed tests, so that a number of subjects undoubtedly inferred that they were expected to read the passage as rapidly as possible. The results may therefore be a trifle better than the general average. In the form-board (Table XIII) and hand dyna- mometer (Table XIX) tests the patients were, again, invariably urged to do their best, and only their best records are averaged in the tables. Each one was given three trials each with the Vineland pattern VARIATION OP MENTAL AND PHYSICAL TRAITS 63 form-board and the Smedley dynamometer, but the tests were repeated during second or third sittings for many subjects, so that frequently the figures utilized are the best single records in from six to nine trials. It may be said, parenthetically, that the best form-board record was by no means always the last one ; on the contrary, many epileptics lost with prac- tice or familiarity. Uniformly, the form-board was placed directly in front of the subject, with the side containing the star nearest. The subjects saw the blocks removed from their proper places by the experimenter. The blocks were thrown into a heap on the table along the far- ther side of the board, instead of along either end, so that they should be equally distant from the two hands. Either hand could thus be used with the same ease. The subjects were told to use only one hand. The same uniformity of procedure was used in the dynamometer test. The instrument, properly ad- justed to the size of the hands, was placed by the experimenter, dial up, in the subjects' hands so that the palms always faced up. Two results thereby fol- low: (1) the subjects were able to see the movement of the registration pointer; and (2) the thumb sides of the two hands, which probably exert a greater pressure than the little finger sides, came into con- tact with the opposite ends of the stirrup of the dyna- mometer. This circumstance may be of some impor- tance in dynamometry work, as indicated by a series of calibration tests of the instrument, which showed that the same weight on the two sides of the stirrup does not give exactly the same reading. The weights were suspended from the stirrup by an iron hook, so made as to move freely (without friction against any stationary part) 64 EXPERIMENTAL STUDIES OP MENTAL DEFECTIVES when the dynamometer was lifted from the dial end. Thus pressure was exerted on the stirrup in much the same way as when it is squeezed by the hand. The hook was suspended from one of three points on the stirrup : the middle and either end. "Normal" indicates that the weights were lifted slowly or with moderate rapidity ; "fast," rapidly or with a quick jerk. (The weights were weighed on a new pair of platform scales, so that the weighing is probably correct.) TABLE IX. Calibration Tests of the Smedley Dynamometer, Objective Weight Result of Normal Lift. Result of Fast Lift. Kg. Right. Middle. Left. Right. Middle. Left. 5.2 4.7 5.2 4.7 12.4 10.3 11.7 10.0 16. 19. 16.5 14.1 16.4 14.3 15. 24.7 16.1 31.7 28.2 30.6 27.4 36. 48.2 45. 45.7 35.5 60.3 48.8 58.2 64.9 The figures are averages of from three to twenty trials. A number of interesting facts; appear from a study of these figures. (1) Pulls on the right and left side of the stirrup practically always gave a different reading, usually amounting on the average to a frac- tion of a kilo (but with a maximum of nearly 10 kg.). In most in- stances the right side of the stirrup gave the larger registration. (2) The middle pull in all cases gave the highest registration presumably because the pulls at the ends occasion friction along the sides of the piston. The difference between the middle and side pulls ranges be- tween 1.4 and 3.2 kg. (two extremes excepted) a difference so large as seriously to threaten to vitiate dynamometry work. Consequently it is of the utmost importance in testing with the Smedley dynamom- eter that the subjects exert the pressure along the MIDDLE of the stirrup. This precaution is by no means always observed, particu- larly not when readings are taken while the handle has been allowed to slide out of the palm on the side opposite the thumb. In this case the pressure is exerted at the end of the stirrup, with a consequent loss. In the present research the attempt was made to secure middle pressure. This instrumental defect should be remedied. (3) If we consider the middle registrations, it appears that the dynamometer in use was not true to scale, except for one or two weights. The spring was slighty too stiff. The inaccuracy, moreover, seems to in- crease with increasing pressure, as shown by these differences for the successive weights (beginning with 12.4 kg.) : .7, .1, 1.1, 2.5 and 2.1 kg. In the interest of scientific precision, dynamometers must be calibrated as accurately as possible and tested objectively from time to time. (4) The testing with the same weights sometimes differed quite considerably on different days (the tests were made be- tween December and March). This may possibly be due to tempera- ture or other atmospheric changes which may alter the tension of the spring. Is this a remediable defect? (5) The differences between the VARIATION OF MENTAL AND PHYSICAL TRAITS 65 "normal" and fast or jerky lifts were large, amounting, for the "mid- dle" readings, to 7.3, 8.3, 5.4 and 6.7 kg. for the different standards. (The friction of the recording pointer was kept uniform during all the tests.) The quick lifts or jerks, of course, invariably gave higher readings. It is therefore evident that dynamometry results may be invalidated, for purposes of comparison, by differences in the method of squeezing. I have found that most subjects tend to apply a steady, gradual pressure. But there are many who give a rapid or violent squeeze. Nearly all of our tabulated results were obtained by the first method. The readings, however, according to the above figures, appear to be somewhat too low. It should be added that no results are tabulated from subjects having any but slight injuries in one or both hands or arms. Finally, in the ataxiagraphic test (Table XXII) the subjects were required to stand under a small horizontal sliding board, to which was fastened a tracing record-sheet of white paper. The board could be moved vertically, so that it could be adjusted to any height of subject, and also sagittally, so that the ataxiagram could be properly placed on the paper with reference to the antero-posterior axis. The ataxiagram was made by a soft marking pencil, which was glued to a band of spring metal, attached to a sort of ataxiagraphic helmet, which consisted of two curved encased metal bands fitting snugly over the cranium. The spring kept the tracing pencil in con- stant contact with the paper, except when the subject dropped the head or swayed too much. In such cases the experimenter was sometimes able to lower the tracing sheet, or if not, to trace the record by hand with sufficient accuracy. In a number of cases in which the ataxiagram extended beyond the paper it was possible for the experimenter to determine the extent of the departure. At the beginning the spring was depressed by the experimenter's hand until the record board had been properly adjusted. The start- ing point on the ataxiagram, the point of initial con- tact, or a point not far removed from this point, would have afforded four measurements, anterior, posterior, to right, to left ; but the data for this tabu- lation are not now available, so that in Table XXII only the gross measurements are given for the an- tero-posterior and lateral sways, irrespective of the point of initial contact. Two methods were employed in this test. In the first, the subjects were instructed to stand with the feet placed to form a V (heels together). In one series the eyes were closed, and in the other the open eyes were allowed to rove at will. In the second method they were instructed to stand with both heels and toes close together, with hands hanging along the sides, and the eyes, when open, fixated on a black disc (about 1 inch in diameter) attached to the win- dow curtain about 12 feet away. The disc was ad- justed to a level with the subject's eyes. In neither method were the subjects instructed to try to stand still or rigidly, but simply to stand naturally. Noth- ing was said regarding the object of the test. With both methods about half the subjects were first tested with the eyes closed and about half with the eyes open, and each test (given in close succession) lasted exactly one minute. Table XXII contains the data secured by the second method only. A search of the available literature indicated that there has been no uniformly observed method in this test, but the sec- ond method here described seems to the author to possess most merits. The limiting of the tabulation to the second method explains, in part, why no more records are used in the study (104 males and 40 females) : the station of many patients was taken by the first method. Another reason is that ataxia- grams secured from ataxic, choreic, paralytic, para- VARIATION OF MENTAL AND PHYSICAL TRAITS 67 plegic or hemiplegic subjects were excluded from the tabulation. Accordingly, the ataxiagrams used should represent the body sway in epilepsy uncompli- cated by special permanent motor disturbances. It should be added that a number of patients, particu- larly low-grade ones, either did not fixate the disc at all, or allowed the eyes to rove more or less. ANALYSIS OF THE AVERAGES. In Tables X, XI and XIII an increase of efficiency or capacity with increasing B-S. age is shown by a progressive diminution of the time of execution. In the corresponding graphs (II, IV and VI) this is shown by a drop in the curves. The Time Needed to Name the Four Colors Red, Yellow, Green and Blue. The time required to name the four colors, Table X, does, indeed, decrease with increasing B.-S. age, but the decrease from year to year is not very regu- lar, as seen at a glance in Graph II. There are numerous exceptions in the averages for the general population, the children and the adults. The excep- tions are least numerous among the girls and women. The differences, however, between the groups, the imbeciles and morons, for all patients, 4 seconds, and especially between Age III and Age XIII, about 7 seconds, are quite considerable. The difference be- tween the averages of Ages VI and VII and of the moron group is much greater for the adults than for the children (3.7 sec. compared with 1.1); for the girls than for the boys (.9 as against .2), and for the men than for the women (6.8 as against 3.1). 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IO t-; eo eo to 00 oo O4 to M_g o-S-^ s: es s fS CM CM CM H H rH **'' 8"* 1 * K O 00 O CM ?: rH 00 t- 00 CO OO S ^aSrtl^^^g * CM s "^ * S a'u'S'5 U u rH rH rH CO t- eo rH - CM CM n aoo * *5 2 fl * - : cv cu 4, c>^ a) s r rl t. t t-i i- ( t t ^ _, " a JH *J^H ^"S Si = ~ ' > > > ^ S X O X > |5 a| ? VARIATION OF MENTAL AND PHYSICAL TBAITS 69 averages for Ages VI to XIII, from which it appears that the girls are superior to the boys (average of 4.9 sec. compared with 5.7) ; the women to the men (5.2 compared with 7.9) ; and the children to the adults (5.7 compared with 6.5). In such a simple trait as the time of naming four colors it may be as- sumed in harmony with the above findings that in- creasing maturity will not accelerate the speed after the colors have once been really learned. The following conclusions seem to be justified : (1) Significant sex and maturity differences (dif- ferences between the juvenile and adult periods of life) are brought out in so simple a test as the speed of naming the four fundamental colors. Epileptic children are superior to adults, and girls and women to boys and men. That normal girls excel normal boys in the knowledge of colors has been shown be- fore. Bobertag recently found this condition to ob- tain in this very test. Moreover, it is stated that color-blindness is more prevalent among males than females (in about the proportion of 4% to .5%). There is a bigger difference between high and low grade adults than between high and low grade children. (2) This trait (the speed of naming the colors) apparently reaches its maturity at about Age IX. (3) In this test the increase with each increasing B.-S. age is not very regular, indicating either that the subjects are not very closely classified or that this is not a very satisfactory test by which to check the accuracy of the scale. eq co in co ca co ,5 .N <-> 3 S S S O O 10 S S3 8 ce in oo o cp co t* co 5 |2 co M S M w *^ X * c X a in ft S S8 M a T "S E ft I s a " t- 3 55 > * co \h s I 3 * S | to | ^rii CO rH V IP 00 CO < ia SS 1 . S? to oo oo oo u-. !J ft; * i o ca eo co 01 rH t- CO 1 * W - ' 1 rH 53 S rH *' ffi S co V S 3 o> s ^ * in 0t o a > I s ' S CO S si 00 55 "ftf * " CO t- t- rH n la U, *" < U s s 1 rH in rH CO i oo co m co S S s 5 h-< .5 fi> e > * in co * C-l o 00 CO OB t* 9> S3' co co t^ in rH CO |X cj cj j P 1 rH rH rH rH 3 o ja a <=> > O O O O o ** O CO * 5 la s 2 4 I i t~ ci rH eo > oo * 4 55 8 s rH 5 M a ^ 1 e E aJ *? " s * o co e> - o >. 00 0. a * 01 K- T Q >i ^* !j cp 2 ! g' 5? S ^ rH CO s rH 9 < | i o o eo < P t* rH 00 to CO t- 2 8 ft> " it- O C> w t- M 00 00 00 8 > .0 "". 10 e> ' S S S 06 CO 3 "' rH w ' Mi To 15 2 2 B in o o e e m a s a St- CO CO CM CO c-l s & 55 > a 2 S 4; o u > M eo e) * t- 9 rH o e* *- r* B * 1 > 12 * a 1 * R J2 $ a s Q) irt 5 S 9 | M 1 * O CO ^< in o 2 ft? I-' 5 rH rH W rH . ^"^ CO f> * > O C! Cl ia 0> to * & i ^ co in rH C4 rf< C^ >e H ^ d Co Cw ^^1-1 d h . V aj t = a S S S g l-l ^ 95 4 11 S . ^ r* eo SIO IO 4D 3! SS S < r-J CO S III aj . Ill VARIATION OF MENTAL AND PHYSICAL TRAITS 71 The Time Required to Read the Passage About a Fire. On the other hand, the time required to read the selection, Table XI, decreased appreciably and regu- larly (as is strikingly apparent in Graph IV), with only one exception among the girls, and two each among the men and women. The reading time ranges from 129.2 sec., Age VII, to 18.5 sec., Age XIII, a difference of 80.7 sec. The difference be- tween the averages of Ages VI and VII and of the moron group amounts to as much as 56.1 sec. for the general population, 111.7 for the boys, 50.8 for the women, and 30.1 for the men. The shortening of the time from each age from IX to XIII amounts, re- spectively, to 24.6, 17.3, 18.1, 3.3. and 4.7 sec. a series of progressive improvements. The largest and most consistent improvements in these years are made by the boys and men (ignoring the girls and children, where the data are incomplete), as seen in Table XII. TABLE XII. Improvement in Reading Capacity with each B.-S. Aye. (The figures represent the gain in seconds made "by a given age over the next preceding age, based on Table XI.) Age. Boys. Girls. Children. Men. Women. Adults. IX 49.6 81.0 77.5 31.1 .4 14.0 X 33.1 3.0 26.3 16.8 4.6 15.6 XI 35.7 28.4 8.0 13.7 14.6 11.9 XII 11.8 8.7 12.6 1.7 XIII 7.5 1.0 12. 4.0 Ave. 27.5 35.5 37.2 13.8 3.8 9.4 A minus sign indicates loss of efficiency. From Table XI it is apparent that, in respect to reading ability as gauged by time, the girls are dis- 72 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES tinctly superior to the boys ( shorter time in all ages and in the averages) ; the adults to the children (in all ages and the averages), and the women to the men (in six of eight ages and in two averages). We may accordingly conclude that the reading test is a valuable test for four reasons : (1) It discloses significant sex and maturity dif- ferences. Here the epileptic females surpass the males and the adults the children. But the difference between the high and the low grade groups is great- est for the boys. (2) The considerable superiority of the adults indicates that reading is an adult art, and that it seems to be worth while to teach reading to epileptics in spite of their tendency toward progressive deteri- oration or degeneration. This point, however, re- quires special investigation. (3) Apparently there is a large age-difference in reading capacity, particularly from VII or VIII to XI. The very considerable gain at IX seems to in- dicate that there is a pronounced advance in reading ability for epileptics at this age. At the same time it is seen that the progressive decrease in the reading time is fairly regular from VIII to XL (4) A reading test thus supplies a valid test for differentiating mental capacity and for checking the accuracy of intellectual measuring scales albeit the test is more pedagogical than psychological. As judged by the time of reading, the B.-S. grouping appears to be fairly satisfactory. It seems, therefore, unwise to eliminate the test VARIATION OF MENTAL AND PHYSICAL TRAITS 73 from the scale, as Binet has done in the latest (1911) revision. So important was the reading test in the original B.-S. scale that it was used as the differential between two groups of defectives, the imbeciles and the morons the latter of whom can be taught to read, while the former cannot. The fact that the test is more pedagogical than psychological, and that it represents the results of training, should not neces- sarily militate against its use for psychological diag- nosis. The attempt to teach children to read will probably have been made in the case of the majority of subjects who will ever be tested. The Time Required to Replace the Blocks in the Form-Board. In this test (Table XIII) there are decided and consistent gains (as is markedly apparent for the general population in Graph VI), with three excep- tions each among the boys and girls, and two each among the men and women. The difference between Ages I and XIII amounts to 211.6 sec., and between the imbecile and moron groups 84.4 sec. The differ- ence between the imbeciles and morons is consist- ently larger for the girls than for the boys (97.7 as against 78.7 sec.) ; for the men than for the women (63.6 against 50.9), and for the children than for the adults (89.1 as against 63). On the other hand, the male morons are five times as efficient as the male imbeciles ; the female morons three times as efficient as the female imbeciles; the boy morons 5.5 times as efficient as the boy imbeciles, and the girl morons 5.2 times as efficient as the girl imbeciles. The corre- 1J^ N CO oo 9 0> V V M <-! t- CO * J ~i."~ * 5 * oo 10 00 - 2 V * oo - - " - s O oj 3t 1 v O S > ^ CM 10 lO v: ^_ ^ 1 {? en to 00 iH o oo 10 <^ 00 at 00 at 10 t- IO 10 t-; e at . t T i-t CO CO C4 ^ If i]is *** 9 > 1O to 1O O> ^ ^ ^ r^ *^ *3 t^ f 5 ^ 00 * at 10 CO 04 CM fl ^5 "S *2 G t) 5 it 2 CM at oo at 2 en oo JJ 4i "^ ? ^ t4 " to CM to {_ v en 00 tp at en en CM oo o >" M f g5 eo f ^ * n oo oo 10 CM ^ ;"- " t^ m ^ ^ ^ | I s * O 00 CM 8 ggSw 55 a > w O 00 00 ~ t~ 5 0> CM en en t- -^ oo oo tJ** a> <)I s'^ t & < w .H M oo ^ a "g x" o , 1 "* eo * 10 CM CM at n o * S- a"-*** I z - to to o -a g be [ si C4 ^" s CM 5 ^ oj oj*" a'S 4Jfl 5 (3 . < f | |>a 8 * ot to us to to en g CM s CM CM CM u -^ en =: <-j ol | M |^ .5 1 * M beS s ^ < * CO C-l CO t. at Ci t- o en 2" . C "S J 5 1. z ""* ^ ** *^ > C " C ^ ^ 03 M 00 CM CO CM e M oo en 03 eS 8* 0-w ^ , Ts e ** CO ^* ^* K H ? ^ O3 *a H *^ +J" e * +*5FijHQ08j330 o ~ O rt e 10 oo c*> CM *p 9 t- O Cvi ^4 n ^ *-> o > 10 r^ ^ en 10 CO oo jA CO 10 10 w iri 1 -j QJ ^ *j *C sfi tn so I CM r- IO (O - e oo CM 10 CM en CM 00 CO ||ap^| U o to CM p at CM CM < A "StSS^?^ ir 1 ^ 5 s s C4 to CO to s oil CM e> .* 2! !>* *J p o to tt to *? oo ,_ p CO 'p'2 s s S 1 " 1 ^--^ j Ok O to to at CO CO en CO C^ gj CO c^l.g-gSi^S l 2 t-< CO CO w CO oo C4 * aSgSs^-fge ifS si J3 9* o 10 CM 10 CO d 01 00 10 c> CM Cft o to . to 04 V co o ! <=>. at jjiJKJi Ya < O 00 oo 10 s CM s s *j to to t S g l^a |-g M S go 0> !0 to to CM 4 a 5 x a B x a x VARIATION OF MENTAL AND PHYSICAL TRAITS 75 spending figure for the children is 5.6, for the adults 4.2, and for the entire population 5.4. A further study of the sex-differences shows that there is no constant difference between the male and female imbeciles, each being superior in two ages. Among the morons the males are superior in all ex- cept Ages IX and XI. But, in the general average, the females excel by 8.4 sec. Among the men and women the same lack of con- stancy occurs, each being superior in about half of the ages, but the men excel by 8.7 sec. in the general average. Again, the girl imbeciles surpass the boy imbeciles in three of the five ages. But the boys excel in the general average by 24.7 sec., and the boy morons are distinctly superior to the girl morons, excelling in all ages but Age XI, with a general moron average that is higher by 20.9 sec. Finally, the same lack of constancy obtains be- tween the children and adult groups, the former be- ing superior in five ages and the latter in four. But the general average for the adults is distinctly bet- ter (by 17.8 sec.). The gains from year to year, beginning with Age V, amount to 26.6, 20.4, 31.1, 7.0, 4.6, 2.0, 2.8, 1.1 and .6 sec. a progressively diminishing series of im- provements. A comparison of the improvements in the separate columns shows that the gains, as well as the fluctuations (losses), are considerable in Ages V, VI and VII, and that, from VII or VIII on, the capacity functioning in this test becomes more stable : the gains are smaller, and the losses are smaller and less frequent. This appears from an examination of Table XIV. 76 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES TABLE XIV. Gains or Losses made in the Time Required to Replace the Blocks in the Form-Board. (The figures indicate the difference in seconds between a given age and the next previous age, lased on Talle XIII.) B.-S. Age. Boys. Girls. Children, Men. Women. Adults. Males. Females. V 34.3 22.0 28.1 64.5 137.2 48.5 43.0 90.4 VI 62.2 6.4 20.5 92.9 15.9 36.8 50.8 8.0 VII 87.8 4.0 33.7 37.5 15.5 28.0 53.7 7.3 VIII 5.9 3.8 7.6 2.5 9.6 6.3 3.5 13.5 IX 1.2 16.5 7.6 4.4 2.9 3.5 3.6 6.0 X 3.3 5.6 4.0 2.7 17 1.1 2.9 .8 XI .3 3.7 .9 4.1 2.5 3.6 2.5 3.0 XII 2.3 3.0 .7 1.7 1.1 1.3 1.9 1.9 XIII 2.0 .5 1.5 .8 .0 Ave. 7.8 6.4 7.7 9.1 17.0 14.4 8.3 14.2 The boys show a greater average improvement in these ages than the girls, the adults than the children, the women than the men, and the females than the males. Much of the superiority of the adults and females, however, is due to the abnormal gain in Age V. The small gains between XII and XIII are due either to the relative maturity of the capacity at XII, to the fewness of the subjects or to the failure of the B.-S. scale sufficiently to differentiate capacity for these ages. From the above survey we conclude: (1) That there may be certain sex-differences, and differences as between adults and children, in the capacity functioning in this test, but these differ- ences do not appear very clearly with epileptics. Here the males appear to surpass the females, par- ticularly among the high-grade subjects. The boy morons are distinctly superior to any other group, and the adults excel the children both in the general average and in the amount of improvement from year to year. VARIATION OF MENTAL AND PHYSICAL TBAITS 77 (2) The capacity improves quite regularly, in progressively diminishing amounts, with each in- creasing B.-S. age. The irregularities in the lower ages are probably due to the fewness of the subjects. (3) Accordingly, this is a fairly good test for purposes of classification, diagnosis and testing the accuracy of intelligence scales, at least between the Ages of VI and XII. (4) Judged by the time required to replace the blocks, the B.-S. classification of the patients pos- sesses a very fair degree of reliability. If we now turn to the tables (XV, XVII and XIX) in which increasing capacity is shown by increments in the output within fixed time-limits, we find again evidences of improvement with each growing B.-S. age. This improvement is indicated by rising curves in the graphs (III, V and VII). Number of Words Uttered in Three Minutes. The number of words uttered increases regularly (Table XV), with one exception each among the men, women, girls and boys, from 16 words at Age VI to 65 at Age XIII, a difference of 49 words. There is only one skew in the graph (III). The difference between the average of Ages VI and VII and the moron group amounts to 21.2 words for the general population, 25.9 for the boys, 23.2 for the girls, 24.2 for the men, 17.5 for the women, 23.4 for the children, 20.9 for the adults, 36.2 for the males, and 18.2 for the females. The difference between the high and low grade patients is thus greatest for the males (both boys and men) and the children. The differ- ences between each of the successive ages from IX to XIII amount to the following for the entire popu- 01 oo rH CM 00 oiar^io-vcoeocnotou) b^COinOrHCOCOrHOivtOO) r'rH01CM01CO'9'tOlO*COCO I rH COCMCOCMrH rHOJ r %^ t* O O> CM OI OO o oi t- 06 oi co to 2 ^.O-Vfs.OlCOCOCOWtOOk - ~ cjfecOHrcooocooi^'rHT-oioi H 0101CMrHCO-*10tO*CDCO Cu I-CMOO t- O OI CO CO CO | ll rH rH CO -C . OO CO CO rH rH CO 1OO1 f^ f **. O OrHrHoioi OO S *^ O.OrHOlOCOOlCOt^CMCOO >ir> "5>oit^o6co^inot^^ : coo S 3^ CMT' c ^CO'^ < lOCO^COV dCMCO rHrHCOOOt- rH ^ ^ CM rH CO rH rH t^OOCOCMCOrHt-t^ t^t^oicooiocoo .. ^ _ ^..lOCOTfrHrHCM-^O ^ " " 1 ^~ > ^ojcoi < ' < i6 04 CM 10 05 s g| . o i ru - oo^rHOoococoo; oocooiooi-icooico CMCMCOCO^lOCOCOCO H i fe [5 I,- Iz rH 01 T- ., morons. ts, males, d women Z a o +3 S - ' rH O * *J^H =oS oi oi o oi CO CO lO t-; O co oi in to <-< CM CO 'C IO t- OO CO O co co oi * rH rH rH "* CO rH O O IO CM rH t^ CO rH CO US CO OO tO CO OO CM rH 01 rH 01 CO p CO rH oi CO ^^ > 8* 1 p 10 to * OJ rH X S = X X o 5 S X < Age. Boys. Girls. Children. Men. Women. Males. IX 2.7 17.2 8.7 15.4 12.7 10.8 X 10.7 18.5 13.2 11.1 5.9 10.9 XI 9.2 5.9 10.2 2.4 9.0 5.1 XII 13.0 6.0 15.3 7.3 3.0 17.4 XIII 4.5 8.8 11.6 4.4 VARIATION OP MENTAL AND PHYSICAL TRAITS 79 lation : 11.9, 10.2, 7.7, 8.6 and 5.1. The correspond- ing figures for the separate groups are shown in Table XVI. TABLE XVI. Gains or Losses with each B.-8. Age in the Number of Words uttered in Three Minutes. (The figures indicate the difference in the num- ber of icords given in a given age and the next previous age, as computed from Table XV.) Men. Women. Males. Females. Adults. 14.1 13.8 9.0 8.1 12.3 6.7 7.3 6.0 1.0 9.3 Ave. 8.0 11.9 11.8 9. 8.4 7.9 8.9 8.7 Here the gains are the highest for the girls and children. They continue, though in diminished de- gree, to Age XIII. This indicates, as one might ex- pect in a test of this sort, that the rate of utterance increases beyond the age of XIII, so that a free asso- ciation test might be found valuable at higher levels. (Possibly a controlled association test would be still more valuable at various levels.) In the rate of word utterance the girls excel the boys (better in five of the ages and in the three averages) ; the men the women (better in seven ages and in two averages) ; the children the adults (better in five of eight ages and in three averages), and the males the females (in six of eight ages and in two averages). The following conclusions follow : (1) There are certain sex and maturity differ- ences in the free association test, although the sex- differences do not appear very clearly among these epileptics. (We are speaking of quantitative, not qualitative differences.) The girls seem to surpass the boys, the men the women, and the children the Lr jj.'uiqcot^rHcoeOf-jco j,^ rHrHf-irHrHrHOarH > -~Z . S e ^ rH t^oq CO IA 00 rr * eg , 3'3-j oi co + IA co co in t-^ in a S3 O CO O3 t- O OO rH t- 0** r-i -^- v< t.~" v>i rn g t O kA CO t COOt CO ,Z 11 B^CO CO kA O ^| kA (O OO >O >- ~ ~ J S < cico'<-^ : kAkA'*co^ t^a a &. 5 H g OOrHC^t^^* COkA ofp rH rH CO O4 _ "^ 'O cooMoococo^fcooa 4,^2 ja ^ a i * lAkAOOOOOCOK>* <; rHCOkAkACOt>inr>in 6^-COCOrHrHt- rHCO (Z. rH CO N I> kA OJ O IA CO t- * tH. ^^rHkA9>COCOt>OrHO> ^ l_ 05 a o t 00 l> 9> t~; IA rH ^_ rH rH rH rH *O O O &> ao . OlAt-;OOrHqO in ^ J 2 CO CNCO^'COCOOW in SJS -" O'g .08 4) h* ^ t- OO OO O4 rH o *S^;2hH O rH rH O H rH g ^ u >.a;cot~cocor-oD CM S SC^P 2 ^5 oi o-i *' ^J ^.' t^ * i''*' 1 1 "SS^5 " 12 * ^" CO OO O rH ^u g (>IA q co q co IA N c-i q Z s -_-^ M rH rH oi rH rH rH E^ * ^ * 9 ej fl o UJ J t- p CO IA rH CO > VARIATION OF MENTAL AND PHYSICAL TRAITS 81 adults. The gains with advancing years apparently are greatest for the girls and children, while the dif- ference between the high and the low grade groups is greatest for the males and the children. (2) There is a fairly regular, although slightly diminishing, increase in the capacity with each rising B.-S. age. (3) Accordingly, the test is of value for mental classification and for checking the accuracy of intel- ligence scales. (4) The B.-S. scale fares fairly well under the scrutiny of this test. Facts Reproduced in the Reading Test. The number of facts retained in the reading test likewise increases regularly (Table XVII, Graph V), with one exception each among the boys, girls, women and children ; two among the men and adults, and none for the general population. The increase ranges from 2.1 at Age VII to 7.4 at XIII, a differ- ence of 3.1 memories. The gains for each successive age from VIII to XIII are, for the entire population : 1.6, 1.1, 0.5, 1.2, 0.3 and 0.6. The figures in the sep- arate columns are as follows : TABLE XVIII. Oaint or Lotset with each B.-8. Age in the Number of Unitt Repro- duced in the Reading Test (the figuret indicate the difference 6e- ticeen a given age and the next previous age, based on Table XVI L) B.-S. vfii Boyt. 2.4 Girls. Children. Men. .4 1.5 1.9 Women. 1.1 Adults. 1.4 Malea. Females. 2.0 1.0 DC .8 1.9 1.2 1.9 1.0 1.4 1.5 1.2 X 3.3 .3 2.1 1.0 .3 .3 .8 .1 XI 1.4 .4 __ " 2.6 .9 2.0 1.0 .8 XII 4.9 2.3 3.9 .8 .7 .9 .8 .1 XIII 1.8 1.2 1.8 1.4 .1 1.3 Ave. 1.3 .94 1.8 .96 .7 1.2 1.0 .75 82 EXPERIMENTAL STUDIES OP MENTAL DEFECTIVES The increase in retentiveness thus varies consid- erably from age to age and group to group. The largest average improvements from VIII to XIII are made by the boys, adults and the males. This coincides with the highest memory efficiency, as de- termined by the number of units retained : the boys surpass the girls (in five of six ages and in the aver- ages) ; the children the adults (only in two of five ages, but the averages are higher) ; the men the women (in four of seven ages and in the averages), and the males the females (in six of seven ages and the averages). These facts suggest the following conclusions: (1) The ability to reproduce prose (read by the subject) varies with the sex and the period of life. Here the males and the adults excel in the average amount of improvement from year to year, and the males and the children in the absolute number of units reproduced. (2) There is a diminishing, though not entirely regular, increase with each increasing B.-S. age. (3) The irregularities found in the age curve in the various columns are due either to the fewness of the subjects, to the peculiarities of the groups (epi- leptics), or to defectiveness in the B.-S. classifica- tion. In general, however, the results speak more strongly for the validity of the B.-S. scale than against it. (4) The test, in any case, is a valuable test for purposes of diagnosis or classification. Whether it is preferable to base the number of facts reproduced on the logical units, following B.-S., or on phrase or thought unities, has not yet been determined. The scoring can be made both qualitative and quantita- VARIATION OF MENTAL AND PHYSICAL TRAITS 83 tive. Possibly the best plan is to base the scores on single-idea unities, and scale the scores according to the relative significance of the items (a combined qualitative and quantitative measure). Manuometry. The strength of grip (Table XIX) likewise in- creases with the degree of intelligence, although the gain with these patients is by no means always regu- lar, as is most easily seen by referring to Graph VII. For the right hand there are four exceptions each for the general population, boys and girls ; three each for the men and adults, and two each for the children and women. For the left hand there are four exceptions among the women and girls, three among the men and adults, two among the boys and entire popula- tion, and one among the children. Apparently the gains are more consistent for the left than for the right hand, and for the children than for the adults. By tabulating, as in Table XX, the amount of the gains and losses in each age from V to XIII, we not only see more readily the irregularity of the increase from age to age, but we also perceive that the sums of the average gains for the boys, girls, men and women, after the losses have been deducted, are somewhat larger for the right than for the left hand (8.4 as against 5.5 kg., whence the more intelligent, the stronger relatively is the right hand) ; that the children gain more relatively with the right hand than do the adults ; that the boys gain relatively more with the left, but the girls with the right hand ; that the men gain more than the women, and that in all cases the strength of both hands is less for the XIII- year-olds than for the XH-year-olds. I** o -r ? 5 Si n r J 3 e > ' X I e I * ^ S S3 ^ s 2 - ^ S ' r- "? SJ 8 s x & ti 3S VARIATION OF MENTAL AND PHYSICAL TRAITS 85 86 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES It would be important to know how far these pecu- liarities or irregularities are due to the small number of subjects tested in certain ages. The difference between Ages III and XIII for the entire population is 12.9 for the right hand and 15.3 kg. for the left hand; the corresponding differences between the imbecile and moron groups are 11.6 and 12.2. That the gain of the morons over the imbeciles is not uniformly greater for the left hand is seen from the following tabulation : TABLE XXI. The Amounts in Kg. by which Morons excel Imbeciles in Strength of Grip (based on Table XIX). Right Hand. Left Hand. Boys 13.1 kg. 14.1 Girls 10.6 7.9 Children 13.6 13.2 Men 9.3 11.2 Women 8.0 5.5 Adults 10.8 10.2 The gain of the high-grade over the low-grade patients is relatively larger for the boys than for the girls, and for the children than for the adults. With respect to the comparative strength of the right and the left hands, the evidence is conflicting. The general average for the left hand is .5 kg. higher (index of right-handedness = 1.01%). It is higher for the boys (index = 1.03%) and women (index = 1.02%), and lower for the girls (96%) and men (98%). Among the morons it is higher for the boys (1.02%) and men (1.01%), and lower for the girls (92%) and women (99%) ; and among the imbeciles higher for the girls (1.03%) and women (1.10%), and lower for the boys (99%) and men (96%). The index is about the same in the two groups. The aver- VARIATION OF MENTAL AND PHYSICAL TRAITS 87 ages for the boys are higher for the left hand in five individual ages, lower in three, and equal in three: for the girls they are higher in half the ages ; for the men, higher in six ages and lower in five; for the women, higher in seven and lower in four; for the children, higher in half the ages, and for the adults they are higher in six ages and lower in four. It is apparent, therefore, that the left-hand grip is stronger in some epileptics and the right-hand grip in others, with the odds rather in favor of the left hand. It has been claimed that degenerates have a stronger left-hand grip, but the rule is by no means invariable, at least so far as epileptics are concerned. For normals the right-hand grip has been found superior, the index varying from 81 to 96%. This contrasts with our index for the entire population, 1.01%. But there are probably exceptions among normal persons also. If the dynamometry results leave us in doubt re- garding some points, the superior strength of the epileptic boys and men is unmistakable, just as among normal persons. There is no significant ex- ception in any column. The superiority of the boys, compared with the girls, amounts to 8 kg. for the right hand and 9.7 for the left, and the superiority of the men, compared with the women, amounts to 16 and 14.9 kg. for the two hands, respectively. The difference is not only large, but the male superiority is relatively greater among the men than among the boys. Among normals, likewise, it has been found that the divergence grows more marked from the time of puberty. Likewise the difference between the moron males and females is greater than between the imbecile 88 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES males and females, as indicated by these figures : the right and the left-hand grips of the boy imbeciles surpass those of the girl imbeciles by 6.2 and 5.6 kg. ; for the adults the corresponding figures are 15.0 and 11.7. But the grips among the boy morons exceed those of the girl morons by 8.9 and 11.8 ; the corre- sponding figures for the adults are 16.3 and 17.3 kg. Analogous results, I believe, obtain among young and old normal children. In the imbecile group the difference is greater for the right than the left hand, while the reverse is the case among the morons. The sex-difference is thus less in the young and the intel- lectually inferior than in the more mature and intel- lectually superior. Another unmistakable fact is the superior strength in all the groups of the adults as compared with the children. In the general averages this superiority amounts to 7.5 and 7.7 kg. for the right and left hands, respectively; in the moron group the corre- sponding differences are 5.1 and 5.4, and in the imbe- cile group 7.9 and 8.4 kg. It thus appears that many epileptics grow physically stronger as they pass from childhood to adulthood. How long this increase continues among normal persons has not been deter- mined. Summarizing, we may say : (1) The dynamometer test reveals significant sex and maturity differences, and differences between the right and left hands. The males are stronger than the females, whether epileptic or normal ; the adults and the morons among epileptics relatively more so than the children and the imbeciles. The absolute strength is greater for the adults and morons: the younger and inferior (lower grade) are relatively VARIATION OF MENTAL AND PHYSICAL TRAITS 89 nearer together than the older and intellectually superior. The left-hand grip is stronger with some epileptics, the right with others ; but altogether the left hand is apparently slightly stronger, as seen most clearly in Graph VII. The index, 1.01%, is quite different from the normal index, from 91 to 96%. It is seen that the epileptics approximate a condition of ambidextrality, just as dull and feeble persons do. The latter have "two left hands" (Binet and Vaschide). A positive correlation has also been asserted between dextrality and intel- lectual ability for normal children (Smedley). (2) There is an increase in the strength of grip with increasing B.-S. ages, but the increase from age to age is not entirely regular. This indicates either that the B.-S. classification is not entirely correct, or that epileptics do not follow the rule obtaining among normal persons, who show an increase with each chronological age (Smedley), or that the irregu- larities may be due to the fewness of the patients in some ages. The gains with increasing age are greater for the boys than for the girls, for the chil- dren than for the adults, and for the right than for the left hand (although the difference between the low grade and the high grade subjects appears to be greater for the left hand). (3) Our results are in harmony with the finding for public school children, that the most intellectual are the strongest (Carman, Smedley, Schuyten). (4) Dynamometry is a valuable test for purposes of diagnosis ; its value for purposes of mental classi- fication and for testing the accuracy of intelligence scales needs to be determined with greater accuracy with normal persons. So important has the grip 90 (hand grasp) of an individual been considered that Barr regards it as more indicative of capacity than the language test : hand grasp and mental grasp go hand in hand (Mental Defectives, 1910, p. 162 ).* Ataxiagraphic Sway. An examination of Table XXII and Graph VIII shows that there is diminution with increasing B.-S. age of the bodily sway, both lateral and antero-pos- terior, but that this diminution is by no means regu- lar from year to year. Nevertheless, if we examine the averages for the two groups, we find that the sway is less for the morons than for the imbeciles, with one exception (females, eyes shut). From Table XXIII, it appears that the group difference will vary from nearly zero to almost 20 mm., that the differ- ence in absolute terms is larger with the eyes shut than with the eyes open (one exception), that the difference for antero-posterior is larger than for the lateral sway, and that the sex-difference is only ap- parent with the eyes fixated. TABLE XXIII. Amount* by which the Ataxiagraphic Sway of Imbeciles exceeds that of Morons (based on Table XXII). r- Eyes shut-^ . ,-Eyes fixated-^ A.-P. Lat. A.-P. Lat. Mm. Mm. Mm. Mm. Entire population <-. 16.9 14.8 11.6 7.7 Males 13.5 12.0 9.1 21.9 Females 15.0 12.1 15.1 .8 From Table XXIV, which gives the difference be- tween the absolute sway of the males and the fe- males (a positive number indicating that the sway 1 In a later contribution the dynamometry data will be tabulated ac- cording to chronological ages and compared with normal performances. ^ H S f > - M 4 r I C 00 00 CO 00 - CO 09 to CO Is* 9 04 00 in CO O 8 m CO 17) 00 CO o 10 CO 10 m CO 9 CO in to to 0* in CO e in 00 *;* 1 *fl M, to 0) a. (. 00 00 9- in CM I s c- IO ** M * e co 00 t- I >: in * (; IO 9 CO H> ot t- 00 o 00 IH tt> m 09 in in 09 10 to O> Ok 10 to CO CO [ ^ t* in , r. 04 O 00 00 IO "3 S IO 04 10 t* 10 co 10 09 00 CO 9 c-i A O CO C* 04 O M O B 3 s z I * < IO 10 S to 00 00 i - 4 00 to CB O in CO in r-. CO CO in on CO CO "3 s fj l> oc a oo K i CO 00 10 to lillimeterc 03 * tsi r > jj 9 a; O 9 S W t e> -0 10 M 10 3 IO n i CO 3 > CO oo r> 10 ti 09 Ml O M 00 00 in <7> B * O ci t- CA CO in 00 5 at CM <0 O in 09 e> CO s IO S S 09 Ey*o Kix.it.'. t A.-P. Lt fm. M V. Mm M o. t- t- O O 00 10 00 in 8 00 on 10 M M 10 cj Cl CO 3 Oi IO CO 04 Ml e M i.-j CO r- CO CO o 04 CO i 00 00 CO CO in' 01 i to * CO to CO CO i t s n r-i a. f > CO *- CO 00 2 ^ - 2 CO CT. llj CM ^ CM K t s CO I > in in * 10) Kl 00 M 2 S a M S in CO CO CO i m in CO g i 2 T^ i - % m M CO ! " in * n = 1 i n HO Of B 0* >o n S X K C K 5 ^ 5 f < 92 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES is larger for the females ; a negative, larger for the males), it appears that, while the difference between the sexes is not very considerable in most cases, the sway is larger for the females than for the males. TABLE XXIV. Sex Differences in Ataxiagraphic Sway (based on Table XXII). r- Eyea shut-^ , Eyes fixated-^, A.-P. Lat. A.-P. Lat. Mm. Mm. Mm. Mm. Average of all ages .5 4.9 2.2 2.6 Morons 1.1 3.4 1.7 12.5 Explanations of signs above. The exceptions are the antero-posterior sway, eyes shut, both groups; and eyes fixated, morons. This seems to show that there is an ataxiagraphic sex- difference in epileptics associated with the lateral direction (larger relatively to the antero-posterior sway for females than for males). The exceptions can be gleaned from Table XXII. To summarize: (1) Apparently the ataxiagraphic sway varies with the sex, and with the eyes shut and open. It is slightly larger for female than male epileptics, par- ticularly in the lateral direction. The closing of the eyes accentuates the sway in both directions, more for the low than for the high grade cases. (2) The antero-posterior sway is usually consid- erably larger than the lateral, as is strikingly ap- parent in the Graph VIII, for eyes fixated. (3) The ataxiagrams are clearly smaller for the moron than for the imbecile group, so that there ap- pears to be a difference dependent upon the degree of intelligence. But the dependence is not very pre- cise, as the diminution of the sway from year to year is not very regular. (4) This is a valuable test for diagnosis in vari- VARIATION OF MENTAL AND PHYSICAL TRAITS 93 cms conditions, but before we are justified in using the test for purposes of intellectual classification or for checking intelligence scales it must first be dem- onstrated that the bodily sway among normal per- sons varies with the degree of intelligence. 1 ANALYSIS OF THE MEAN VARIATIONS. As a measure of the reliability of averages or the uniformity between the separate counts, whether averages or single determinations, which make up a series of determinations, we may use the mean vari- ation (M. V.). The reliability of the central tend- ency varies inversely with the size of the relative M. V. If the M. V. is large in relation to the size of the average (i. e., if the relative M. V., or coefficient of variability, is large), the average possesses little reliability. Likewise, if the measurements of a given trait from numbers of subjects grouped in the same mental age vary considerably, it follows that the test in question is not properly placed (not well attuned to its correct age) or that the variation is normally so large for the given trait that the test is worthless as a norm for a given age. It is clear that, in the very nature of the case, a norm is normative by reason of the fact that it indicates, within a certain range of variability, the expected performance for the age to which it is assigned. The larger the variability, the larger is the uncertainty of the norm; if the varia- bility is as large as the average, the latter, of course, fails utterly to represent any central tendency. At the same time, one must recognize that mental meas- l ln a later publication the ataxiagraphic data will be tabulated ac- cording to chronological age, and compared with the ataziagrams for normal persona. 94 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES urement is concerned with the determination of tend- encies, not of absolute constants, and that a certain degree of variability of performance is thus per- fectly normal. The M. V. of a series of determinations is not very reliable unless the series contains a reasonable num- ber of observations. Because our number of sub- jects is small in some of the ages, it will be advisable to confine the analysis to the larger averages. The details may be left to the reader to glean from the tables. The coefficient of variability in the time required to name the four colors amounted to 28% for the en- tire population, 26 % for the boys, 36% for the girls, 39 % for the women, and 57% for the men. In the amount of irregularity the boys rank highest and the men lowest. The M. V. is larger for the imbeciles than for the morons. The variation is considerable in all the ages, and in Age VIII, in which the test is placed, it is even larger (37%) than for the general average. The coefficient of variability in the time needed to utter sixty words amounted to 25% for the entire population, 18% for the boys, 22% for the women, 28% for the girls, and 33% for the men. Here, again, the boys are the most regular and the men the least. The M. V. is considerable in most of the ages, and in Age XI, to which the test is assigned, it amounts to 24%, as compared with 13% for Age XII, the age to which it has been transferred in Binet's latest revision, and the age in which it is satisfactorily passed by our patients. The coefficient of variability in reading capacity, based on time, amounted to 28% for the entire popu- VARIATION OF MENTAL AND PHYSICAL TRAITS 95 lation and for the women, 26% for the girls, 29% for the boys, and 31% for the men. While the male sex appears to be the most variable, the differences are not very material. The amount of the variation dif- fers greatly in the different columns, but it is usually considerable in each age. In the ages in which the test is placed, VIII and IX, the coefficients are consid- erably larger than any of the above figures, namely, 41 and 50%, respectively. Even in Ages X, XI and XII, the coefficients amount to 60, 31 and 42%, so that while the average reading time diminishes with age, the variation among individuals continues large a fact of common observation. That the amount of irregularity is partly due to the presence of a few very slow readings is indicated by the fact that the medians are uniformly and con- siderably smaller than the averages in Ages IX, X, XI and XIH. The coefficient of variability in memory capacity (memories from reading test) is 25% for the entire population, 15% for the boys, 24% for the girls, and 30% for the men and women. This points to a greater regularity, or homogeneity, of memory-capacity among the boys and a less regularity among the adults. In this respect the epileptic adults are obvi- ously much like the senile adults among normal per- sons. We have already seen that memory capacity among the children, as measured by the number of units retained, excels that of the adults. The size of the M. V.'s varies a great deal in the various ages and columns. The coefficient is 27% in Age VIII, in which the average number of memories is 3.7, instead of 2 as required by B.-S., and 27% in Age IX, in which there are 4.8 memories instead of six as re- 96 EXPERIMENTAL STUDIES OP MENTAL DEFECTIVES quired by the scale. This indicates (1) that the dif- ference in reproductive capacity between VIII and IX is not so large as indicated in the scale, at least for epileptics, and (2) that the variation for these ages is even larger than for the general average. On the other hand, the coefficients of variability in Ages XI and XII are only 17 and 19%, respectively. The variability in the test of motor performance the form-board amounted to 24% for the entire population, 25% for the women, 27% for the boys, 39% for the men, and 47% for the girls. Here the greater regularity in the boy and woman groups is manifest. The same truth appears if we confine the comparison to the morons : boys, 16% ; women, 16% ; men, 17%, and girls, 21%. The differences are slight, however. It is noticeable that the absolute M. V. is considerably smaller (at least in two cases) for the morons than for the imbeciles, and that the absolute M. V. decreases markedly with age. The exceptions are probably due to the fewness of the subjects. The variability is 14% for Age IX, 18% for Age X, 10% for Age XI, and 7% for Age XII. If we assume that the regularity of performance of a given activity increases with age, it appears that the patients are fairly well classified. The coefficients of variability for the right and left hand grips are shown in Table XXV. TABLE XXV. Coefficients of Variability in Hand Dynamometry. Right. Left. Entire population 20% 20% Boys 24 24 Girls 25 23 Men 13 15 Women 16 17 VARIATION OP MENTAL AND PHYSICAL TRAITS 97 It appears that the irregularity is about the same for the right and left hands, for the girls and boys, for the men and women, and considerably less for the adults than for the children. The coefficient is con- siderably less for the morons than for the imbeciles, the percentages for the right hand being, respec- tively, 16 and 25, and for the left hand 14 and 26. (Among normals the variability has been found greater in early adolescence than at any other time.) The relative M. V.'s for the body sway are shown in Table XXVI. TABLE XXVI. Coefltcientt of Variability in Ataxiagraphic Sway. r- Eyes shut-^ /Eyes fixated-^, A.-P. L. A.-P. L. Entire population 24 29 24 34 Males 27 29 23 28 Females 21 30 33 34 It is seen that, without exception, there is among these patients less relative variation in the antero- posterior than in the lateral sway ; that the variation is not materially different, whether the eyes are closed or fixated, and that the differences between the males and the females do not seem to follow any rule. GENEBAL CONCLUSIONS AND COMPARISONS. 1. In most of the above tests there are maturity differences, that is, differences between the period of childhood and adulthood. The epileptic children excel in the color test (better average and lower M. V.), the 60- word test (better average and better gains), and the memory test (higher average and lower M. V.) ; and the adults excel in the reading test (better average), the form-board test (better 98 EXPERIMENTAL STUDIES OP MENTAL DEFECTIVES average), and the dynamometer test (better average and lower M. V.). Accordingly, an adult who grades, say, X years mentally is not the same intellectually as a child with a X-year mind. The results, however, seem to show that the differences are not so large but that a common scale can be legitimately used for both children and adults unless, indeed, the differ- ences are larger among normal than abnormal persons. Whether the adults attain a higher intellectual sta- tion cannot be determined reliably from the data in this chapter, but must be ascertained from the table of distribution in Chapter I. In this table it appears clearly that the adults reach a higher status : there are appreciably more child than adult idiots (3.7% more) and imbeciles (14.3%), but appreciably less child morons (11.8%) and normals, retardates or de- viates (5.3%). The inference from the mere curve of distribution, however, involves a certain source of error, because there are nine children chronologically less than thir- teen years of age who do not grade as feeble-minded by the B.-S. scale (that is, they are retarded less than three years). These children, therefore, belong to the group of normals or deviates, but could not be so classified because they failed to satisfy the thirteen- year standard. But it is probable that if due allow- ance is made for this error, the conclusion will still stand that the adults are intellectually superior to the children. It would thus appear that the average epileptic, in spite of the dementing tendency of the disease, makes intellectual progress from childhood to adulthood unless, perchance, the onset of the at- tacks occurred late in life or unless the attacks were VARIATION OF MENTAL AND PHYSICAL TRAITS 99 more than ordinarily light in the case of this group of adults, both of which suppositions are improbable. From this fact we may conclude that institutions for epileptics should be made genuine training schools, not mere asylums. 2. There are likewise sex differences in most of these traits. The females excel in the color test (in average speed, although the M. V. is less for the boys), the reading test (average and M. V.), and the 60-word test (average, and gains for girls; but the men also have a high average), and the males excel in the form-board test (particularly in the average for the high-grade patients, and in the average and M. V. for the boy morons ; but the women also have a low M. V.), the memory test (average, and M. V. for boys), the dynamometer test (average, and also gains for boys), and the ataxiagraph test (average extent of sway). It is seen that the epileptic males excel in more tests than the epileptic women, and that the best single group is that of the moron boys. These results are confirmed by three other facts. First, by the table of distribution (Chapter I), which contains a larger percentage of high-grade males than females. Although there are slightly more male than female idiots (.7% more), the male imbe- ciles are fewer (by 1%), while the male morons (by 4.8%) and male retardates (1.4%) are more numer- ous. Likewise if we consider the separate columns, there are less men than women idiots (by 2.1%) and imbeciles (by 2.4%), but more men morons (by 3.1%) and retardates (by 1.3%); and there are more boy than girl idiots (by 5.7%), but decidedly less boy im- 100 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES beciles (by 20.8%) and decidedly more boy morons (11.5%) and retardates (3%). The obvious superi- ority of the boys is confirmed by the above figures, although a relatively large percentage of the idiots are boys. A second means of corroboration is to determine the relative station of the boys and girls by calculat- ing the number of years of retardation for each child, that is, the number of years between the child's chronological age and his B.-S. age. This could not very well be calculated for the adults, partly because the B.-S. scale does not extend beyond Age XIII (we have no other satisfactory tests for the higher ages that have yet been standardized), and partly because the attempt would involve a certain absurdity. Let us assume that two adults, respectively 30 and 40 years old, just grade XX years by a serial intelli- gence scale. We should not thereby be able to say that the 30-year-old is retarded 10 years intellec- tually in the same sense in which a 13-year-old grad- ing III years is retarded 10 years, since the increase in intellectual capacity from 20 to 30 would very probably not amount to 10 years. It would be less than the difference between 3 and 13. Nor, again, should we be able to say that our 40-year-old was retarded twice as much as our 30-year-old, for ordi- narily for the average person there is probably little increase in intellectual strength from 30 to 40 (there would, of course, be a great increase in erudition on the part of the studious). Hence, our 40-year-old would be retarded only slightly more than our 30- year-old. VARIATION OP MENTAL AND PHYSICAL TEAITS 101 Furthermore, in restricting the following tabula- tion to the children, it is well to point out certain pos- sible errors. The amount of retardation is probably somewhat exaggerated in the case of those who pass the tests of the higher ages, as the norms are prob- ably too difficult. Nor, following the above reason- ing, does a unit of retardation mean exactly the same thing throughout the scale. The difference between, say, Ages II and III is larger than between Ages XII and XIII. A 20-year-old person who passes only Age XII, and a 12-year-old child who passes Age IV, would both be rated as eight years retarded, but the eight years from 4 to 12 almost certainly represent a larger difference than the eight years from 12 to 20. Moreover, the retardation is probably exagger- ated for the few who pass Age XIII, because these few might have gone higher, but there was no means of determining this by the scale. In Table XXVII the children are arranged in their chronological (actual) ages from 5 to 20, and the average amount of retardation is given in years for the patients of the same chronological ages. In Table XXVIII the amount of retardation is averaged for the children in each B.-S. age. The grouping in Table XXVII is based on chronological age, and in Table XXVIII on B.-S. ages. Here we see that the boys are retarded less than the girls: in Table XXVII by 0.8 of a year for the general average and by 0.9 for the average of ages 14 to 20 (with only two exceptions in the individual ages) ; and in Table XXVIII by one year for the gen- eral average (with three exceptions in the individual 102 EXPERIMENTAL STUDIES OP MENTAL DEFECTIVES I eo N o 1-1 d eo W i i | \ S L * ? 8 ^ > T- *-* "e 1 T. ?S H > ^ QC r -I 10 " * 13 >> S- 2 BO- _M 2 '* B I 63 I? 22 a I l) O 'l^rH 8 * O 03 05 ^ U SoS > 0,2 JS VARIATION OF MENTAL AND PHYSICAL TRAITS 103 ages). The superiority of the boys, whichever method of tabulation is considered, thus amounts, in round terms, to one year. 1 Finally, if we average the M. V.'s in all tests (ataxiagraphic excepted), we get the following re- sults : Boys. Girls. Children. Men. Women. Adults. Males. Females, 23.1 30.9 27.0 34.0 26.7 30.3 28.5 28.8% There is no difference between the males and fe- males, although the men are inferior and the boys distinctly superior. Altogether we may say, then, with confidence, that the males, and particularly the boys, in this group of epileptics, are superior to the females a fact of common observation at the institution. Further study would determine whether this conclusion is valid for epileptics generally. The conclusion is ob- viously of interest, because, so far as concerns the children, one would expect the girls to surpass the Attention may be directed incidentally to a number of other facts which appear in the above tables. Thus the amount of retardation in general becomes greater as the child grows older, which is evident from the fact that the figures grow larger in the higher chronological ages in Table XXVII. This indicates a progressive loss of intelli- gence with increasing age, relative to the normal improvement, quite analogous to the progressive loss in manuometry exhibited by juvenile delinquents unless, forsooth, this loss can be accounted for by the considerations advanced above. It seems natural that the normal child should outstrip the defective more and more, so that the gap between them becomes progressively larger. On the other hand, the loss with increasing B.-S. ages becomes less and less, the average for Ages I to VII (idiots and imbeciles) being 10.1 and for Ages VIII to XIII (morons and retardates), 5. The pro- gressive loss here is, no doubt, due to the fact that few children at the institution were under seven years of age. The feeble-minded status of the group is emphasized by the fact that the average amount of retardation is over 7 years. Yet there were 4 girls and 5 boys who were merely backward (retarded less than three years). 104 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES boys, since they mature earlier, and because it does not square with public-school statistics of retarda- tion, promotion, elimination and repetition. A study of fifteen city school systems showed that there were more retardates and repeaters among the boys than among the girls (13fo more of each), and a larger percentage of elimination (17%) and non-promotion (Ayres). Either these findings do not apply to epi- leptic children, or otherwise our group has been spe- cially selected in some way. Apparently the disease (epilepsy) plays greater intellectual havoc with girls than with boys. On the other hand, our findings agree with the gen- eralization that there is a larger percentage of males at both extremes of the human scale more very low- grade men (idiots) than low-grade women, and more very high-grade men (geniuses) than high-grade women. The Germans, it is said, have a name for boy geniuses, but not for girl geniuses. Having these sex-differences in mind, a question of moment confronts us: Can we measure the intelli- gence of boys and girls accurately by the same scale? It would be unwise to attempt to answer this ques- tion on the basis of our results with epileptics. It is enough to say that our results emphasize the neces- sity of a thorough experimental study of the ques- tion. 3. The results indicate that the B.-S. scale is rather more satisfactory than appeared from the facts adduced in Chapter II. While it does not scale different grades of intelligence with the degree of accuracy which would be desired, it does enable us to grade and classify defective individuals far more rapidly and satisfactorily than would be possible VARIATION OP MENTAL AND PHYSICAL TRAITS 105 by the ordinary methods of observation. The facts which perhaps tell more strongly against than for the accuracy of the scale are the averages in the color, dynamometry and ataxiagraphic tests, and the coefficients of variability. The latter range from 15% to 57%, and average almost 30%. Mental measurements, of course, are always variables, but the variations in our results seem to be rather too large. In many psychological measurements a varia- tion of from 10 to 15% is considered large. Perhaps we may fix 25% as the maximal permissible coefficient of variability. But we need to determine by experi- mental means what should constitute a normal or maximal coefficient of variability for normal age- groups (normal persons). At the present time we are unable to assign any definite value to the age norm of variation (M. V. norm). 1 No one, however, need be deterred from using the scale before this work has been done. Whatever its imperfections, it affords a practical, easily administered, objective, systematic method of grading defective children and adults, which, while not as yet maximally accurate, approximately locates the mental station of the indi- vidual. At the same time we must not blind our- Tourtis tested 23 eighth-grade pupils, the survivals of eight years of "passing" on a 70% basis (and therefore presumably closely graded), and found the relative M. V.'s to amount to 18% in an addition speed test, "3% in age, 1% in handwriting, * * 15% in formal Eng- lish grammar, 26% in height, 30% in memory of important dates and men, 00% in ability to reproduce after 24 hours the main points of a historical passage read once in class" (8. A. Courtis, Measurement of Growth and Efficiency in Arithmetic, The Elementary Nchool Teacher, II : 1911, p. 533). We shall be in no position to pass on the efficiency of the grading in graded schools until we have grade-norms of variabil- ity similar to the age-norm* of which we have spoken above. In a serial investigation during the past year of various mental traits, I found surprisingly large M.V's, both in respect to the age and grade standards. 106 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES selves to the necessity of revising and improving the scale. 4. The data presented here will help us to a bet- ter understanding, not only of epileptic and other types of abnormal minds, but of normal persons as well, as soon as similar data are obtained from other surveys. Here we can take space for three brief comparisons only. According to B.-S., the time required to read the fifty-three words about a fire was as follows for the ages indicated : Age VIII, 45 sec. ; IX, 40 sec. ; X, 30 sec.; and XI, 25 sec. Comparison with the corre- sponding ages in Table XI shows that the epileptics of VIII, IX and X required considerably more time (the times were 86.5, 61.9 and 44.6 sec., respectively), while the Xl-year-old epileptics required about the same amount of time indeed, if we consider the medians, the time was actually shorter for the X- and Xl-year-old epileptics than for the normals. Here is probably a specific retardation effect incident to the disease (epilepsy). The epileptic children ac- quire the reading art more slowly than do normal children ; in fact, more slowly than the above figures indicate, because many of those who graded X and XI were chronologically from 12 or 13 to 18 or 20 years old. The following were the seconds consumed by the feeble-minded patients at Vineland in replacing the blocks in the form-board for each B.-S. age (accord- ing to figures supplied directly by Goddard) : II III IV V VI VII VIII IX X XI XII 150 90 70 40 35 29 20 19 19 17 15 It is seen from Table XIII that the feeble-minded reacted more rapidly than the epileptic in all ages up VARIATION OF MENTAL AND PHYSICAL TRAITS 107 to and including IX, in some ages very considerably faster, but that from Ages X to XII the epileptics slightly excelled. The higher-grade epileptics thus react pretty much like the higher-grade feeble- minded in the corresponding ages. It should be stated that the epileptics were tested when they were in their normal condition, and not in a state of stupor. In the latter condition the reactions would be markedly lengthened or would cease entirely. Finally, comparison for memory of digits may be made with Jacob's norms for London school children. He pronounced series of digits to about thirty pupils in each age from 8 to 19. The pupils wrote what they retained. The following averages are based on the highest number reproduced i 1 Age. 8 9 10 11 12 13 14 15 16 17 18 19 Ave. 6.6 6.7 6.8 7.2 7.4 7.3 7.3 7.7 8.0 8.0 8.6 8.6 From these figures it appears that memory norms for digits cannot be established for each age. They seem to be approximately the same for several ages : 8 to 10 (6 digits), 11 to 15 (7 digits), and 16 to 19 (8 digits). It would not be profitable at this time to enter upon a discussion of age-norms for digits in the light of these and other available data. To es- tablish these norms upon a satisfactory basis far more children in each chronological age must be tested than has hitherto been done. 5. As may be seen by a cursory glance at the graphs, there is a continuity of variation in all the single traits tested, within the limits of the ages plotted, for epileptics. The variations cluster around *Cf. G. E. Johnson, "Contribution to the Psychology and Pedagogy of Feeble-Minded Children," Pedagogical Seminary, 3: 1805, 208-273. 108 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES one type or mode (subject to certain irregularities in some of the traits), and it is entirely probable that this one-type pattern of distribution would not be altered were the records of normal subjects included. It is impossible to group these traits in epileptics into disparate classes, separated by intervening gaps: they vary continuously from lowest to high- est. Accordingly, the epileptic is not ' ' abnormal ' ' in respect to these traits in the sense that he constitutes a distinct type, a species apart from ordinary indi- viduals. With all his exaggerated " variation" or " individuality, " he still shares with the rest of us a * ' common humanity, ' ' the common humanity of the race. He is not essentially different in kind from the ordinary person. What appears to be a qualitative difference is probably an exaggerated quantitative difference, because the traits of the epileptic fall within the surfaces of distribution for the human kind. He occupies the lower extreme of the surface. (It should be said that I am leaving out of the ac- count the lowest-grade epileptics, who are not in- cluded in our "trait" curves, and that the curves may be considered only indirectly as distribution surfaces.) In conclusion : The great need of a simple, objective scale for in- tellectually grading defective school children and juvenile (also adult) delinquents, for measuring the extent of involution changes produced by dementing psychoses, and for classifying institutional cases of mental defectives of whatever kind, and the present conspicuous lack of a generally accepted or satisfac- tory method, is recognized on every hand. Neither the educator, the alienist, the criminologist nor the VARIATION OP MENTAL AND PHYSICAL TRAITS 109 judge have at their ready disposal a valid method for locating mental station and classifying individ- uals according to degree of mental defect. A graded diagnostic scale of intellectual development com- mends itself because of its great practical utility, even though less valuable for the purpose of exact scientific diagnosis. Because of the present consid- erable utility of the Binet- Simon scale, and its greater prospective utility, to all students who have to do with deviating individuals, no pains should be spared to ferret out its present imperfections, so that an improved scale may gradually be evolved. Until this has been done we may continue to use the present scale, confident that there is no other single instrument available which gives us a superior pre- liminary survey of a defective or mentally deviating individual a conclusion already emphasized by the writer elsewhere. 1 At the same time it is necessary to sound a note of warning: the function of the B.-S., or any other graded scale of intelligence, is to give us a prelimi- nary, and not a final survey or rating of the indi- vidual who may be tested. The B.-S. testing is not to be regarded as a finality, but merely as a point of departure for further diagnosis. It gives us the first, and not the final word about an individual's mental status. Once the individual's mental station has been preliminarily and roughly determined by a graded intelligence scale, there remains the more difficult task of making a detailed, expert diagnosis for each case and a diagnosis of each fundamental trait or capacity. 'The New Clinical Psychology and the Psycho-Clinicist, Journal of Educational Ptychology, 2: 1911, 121 and 191. 110 EXPERIMENTAL STUDIES OF MENTAL DEFECTIVES It is folly to suppose that any ordinary grade teacher who has taken a summer course in clinical psychology, or that any professional expert whatso- ever who lacks technical training in psycho-clinical or psychiatric methodology, is prepared to mentally diagnose defective or deviating individuals, or to conduct psycho-clinical research, or to extend the boundaries of clinical psychology. It would be no more absurd to expect a teacher or preacher or law- . yer or old-line experimental psychologist to diagnose human disease from reading a book on medical diag- nosis. The idea, unfortunately, seems rapidly to be gaining ground that anyone, be he grade teacher, introspective psychologist, practicing lawyer or gen- eral medical practitioner, is able to make psychologi- cal diagnoses by putting the child through a few stock psychological tests. Nothing is more preposterous. The ability to make psycho-clinical examinations and diagnoses requires as high an order of trained skill as the ability to make neurological or general physical examinations and diagnoses. All that can reason- ably be expected from grade teachers, or anyone who has not had considerable first-hand experience in the mental examination of various kinds of mental de- fectives, is that they acquire sufficient skill to give certain standard tests, like those of Binet and Simon, according to directions. It is visionary to suppose that a differential diagnosis of cases can be made by a few routine tests. The results of such testing do have one value, however: they contribute valuable preliminary data for a later individual differential diagnosis by an experienced mental examiner. Clin- ical psychology will more speedily become a genuine science of the behavior of individual deviating and VARIATION OF MENTAL AND PHYSICAL TRAITS 111 abnormal persons, and will develop a practically use- ful art of orthogenics, if we recognize at the outset that the problems of this science are extremely com- plex, complicated and baffling, and that they can be adequately handled only by trained experts. GRAPH H. Time to name t Colors. 3 V 5 7 * m. A/umber of Words /n Three Minutes /Vo. 8 /o // /J VARIATION OF MENTAL AND PHYSICAL TRAITS 113 7/ine to ftead Selection. Sec. us A -S Ages 6 7 e 9 GffAPH /O // / /3 Units Reproduced from ftead/n CT OCT 2 19 EO./ PSYCH EDU./PSVCH- 57 JUL 201972 Form L9-32TO-8,'57(C8680s4)444 education librsr? LC 4601 : 005 644 075 3 A 001 095 669 6