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 THE GROUNDWORK OF 
 EUGENICS 
 
 by 
 KARL PEARSON, F.R.S. 
 
 "You ask whether I shall discuss 'man.' I think I shall avoid the 
 subject, as so surrounded with prejudices ; though I fully admit 
 it is the highest and most interesting problem for the naturalist." 
 
 Letter of Dar^ivin to IVallace 1857. 
 
 SECOND EDITION. 
 
 LONDON 
 
 Published by the Cambridge University Press, Fetter Lane, E.G. 4 
 
 1912
 
 PREFATORY NOTE 
 
 This paper gives the substance of two lectures 
 delivered as an introduction to a Course on the Science of 
 National Eugenics at the Galton Laboratory, February 23 
 and March 2, 1909. 
 
 It is published because the Staff of that Laboratory has 
 found the need of some introduction to the science of 
 Eugenics, which shall place the results of their investiga- 
 tions in a simple form before the layman. The aim of the 
 present series of publications is to state the conclusions 
 drawn from laborious statistical investigations and their 
 bearing on national welfare in non-technical language suited 
 to the general reader.
 
 H<? 
 75-/ 
 fSllf 
 
 THE GROUNDWORK OF EUGENICS 
 
 Does a real biological science of the evolution of hun:ian 
 societies exist ? This is the problem foremost in the minds 
 of many thinkers to-day, and likely in the near future to 
 force itself irresistibly on the attention not only of statesmen, 
 but of all who have the national welfare at heart. 
 
 Can we place ourselves outside the community of which 
 we form a part, and study the effects upon it of environ- 
 ment, of occupation, of nourishment and of breeding in the 
 same judicial manner as the owner of a herd of shorthorns 
 approaches the like problems ? The question cannot be 
 answered with a light ' Yes ' or ' No ' according to the taste 
 or sentiment of the respondent. We are not in the position 
 of the owner, but we are members of the herd ourselves — 
 with all the feelings of our class, the prejudices of our edu- 
 cation or want of education, the strong emotions of our sex, 
 and the complex passions of our race and stock. We cannot 
 make direct experiments on our fellow-men, and study train- 
 ing and nurture and parentage as it is possible for the owner 
 of a thoroughbred stud to do. Yet if these admitted diffi- 
 culties forced us to answer 'No' to our question, they would 
 equally compel us to deny the possibility of a real study of 
 medicine. The clinical ward, the post-mortem room, the 
 pathological laboratory, the asylum and the sanatorium — 
 nay, the bared -soul as well as the bared body of many a 
 private patient — compel the higher type of medical man, 
 who is ever student as well as adviser, to repress sternly the 
 personal and place himself outside the herd for the further- 
 ance of his science and the effectiveness of his craft.
 
 4 THE GROUNDWORK OF EUGENICS 
 
 To him also social conditions render direct experiment 
 largely impracticable. He can only seek for and may 
 possibly discover a group of his fellows, who are making 
 the required experiment on their own initiative. But such 
 is the great variety of human conduct and taste, such the 
 extent of human blindness and folly, that it is possible with 
 time and energy to discover and observe groups of indi- 
 viduals making most of the experiments, which the student 
 of medicine or eugenics might wish to institute had he the 
 aloofness of a superman controlling a herd of men. 
 
 Man himself makes the experiments which are directly 
 impossible for the eugenist. This stock marries kin for six 
 generations ; those parents surfeit themselves with alcohol ; 
 there the tuberculous taint meets insanity ; here the man of 
 genius marries into his class ; there he takes a woman of the 
 people. There is hardly a phase of nurture and of environ- 
 ment, or of parentage and of ancestry which cannot be 
 followed up, — not in a single experiment, but in repeated 
 experiments, — if the time and energy to investigate are 
 forthcoming. 
 
 The science of eugenics does not propose to experiment 
 on man ; it endeavours to lay before us the results of man's 
 experiments on himself, and this in such numerous cases 
 that the evidence must carry with it conviction. Our object 
 is to form an analytical record of man's experiments on 
 himself, to draw from the history of his successes and failures 
 the biological laws which govern his social development, 
 and upon the basis of the knowledge thus gained to predict 
 what lines of conduct foster, what lines check national wel- 
 fare. Conduct may be enforced by a social or by a legal j 
 sanction. The possibilities of enforcing conduct by such 
 sanctions form the subject of ' Practical Eugenics,' which 
 I shall exclude entirely from consideration in this lecture.
 
 THE GROUNDWORK OF EUGENICS 5 
 
 It can only be properly discussed after we have measured 
 the present state of our knowledge, and are able to estimate 
 its relation to our existing social organisation. Before dis- 
 cussing practical eugenics we must know the relative weight 
 of nature and nurture, of heredit}' and race, of environment 
 and training. These are wade subjects, on which at present 
 — even if we confine our attention to man — we have only 
 partial knowledge. Some phases of what we do know will 
 be discussed in the later lectures, and when these are con- 
 cluded we can return with greater fitness to what is feasible 
 in practical eugenics. 
 
 Meanwhile I return to my point that, while the student of 
 eugenics can make no direct experiments on man, he can 
 observe those experiments which mankind is every day on 
 so vast a scale making upon itself. And he has to observe 
 those experiments in the calm scientific manner of the 
 physician in his clinic; he must not be led away to imme- 
 diate action by the first individual case, which appeals to 
 his sympathy and emotions. The general rule can only be 
 learnt when the statistics of many individual cases have been 
 dealt with. Each characteristic, each virtue and each vice 
 is protean in its forms, and not until we have massed case 
 upon case in our experience can we deduce the general 
 drift of the whole series. 
 
 I would illustrate this by an attempt to consider some 
 of the sources of feeble-mindedness in the children of the 
 industrial classes made to my knowledge quite recently in 
 a large manufacturing town. The family history of several 
 hundred mentally defective children was followed up with 
 considerable energy and success. The result was that a 
 most striking amount of alcoholism was demonstrated to 
 exist in the ancestry, and it was supposed that this investi- 
 gation confirmed the view that alcoholism in the parent
 
 6 THE GROUNDWORK OF EUGENICS 
 
 was one of the chief sources of mental defect in children. 
 I suggested that a control series of normal children from the 
 same school districts should also have their family histories 
 worked out; this was a harder task as the parents naturally 
 resented inquiry, but the result showed a ' striking amount 
 of alcoholism ' in the parents of the normal children ! It 
 would have taken far larger and more detailed data to deter- 
 mine whether the intensity of alcoholism was greater in the 
 ancestry of the mentally defective or in that of the normal 
 children. My informant — a very keen and active social 
 worker — adopted the view that the prevalent alcoholism 
 showed that the whole industrial population of the district 
 was degenerate, and that it was purely the result of chance 
 that some families had and some had not produced mentally 
 defective children. All that had been done was to divide 
 the population into two groups by the presence or absence 
 of children of this character. 
 
 Now personally I might not be prepared to accept this 
 view ; I might argue that alcoholism is a sign, just as much 
 as feeble-mindedness, of mental abnormality and not the 
 cause of the latter. But the important point I want to 
 emphasise at present is : that we are not compelled because 
 we find alcoholic parents to the feeble-minded to assume 
 that alcohol is the source of feeble-mindedness. It is a 
 very complex statistical problem to determine whether 
 alcoholism is more or less prevalent in the parents of one or 
 other class of children. And had it been determined as 
 more prevalent, it would not follow that alcoholism was the 
 source of the feeble-mindedness ; both may be different 
 manifestations of the same ancestral weakness. You will 
 find this a useful point to bear in mind, when you note how 
 alcoholism occurs in association with insane, feeble-minded, 
 deaf-mute, criminal and generally defective stocks. But
 
 THE GROUNDWORK OF EUGENICS 7 
 
 association is not necessarily causation, and we may waste 
 on the fight against alcohol energy which could only destroy 
 the admitted social evils, if it were directed to the ex- 
 termination of the degenerate stocks themselves. 
 
 I have dwelt somewhat at length on this problem of 
 feeble-mindedness in children and alcoholism in ancestry 
 because it is not only a typical case, but a nationally im- 
 portant case. It is such an easy stage to pass from the 
 inspection of a few individual instances to a state of intense 
 social feeling — to the demand for the use of the axe in the 
 beer saloon — that we want above all things some calm 
 scientific investigation of human society and its biological 
 growth removed from the cries of the market-place and 
 the appeals of political parties. It is on this ground that 
 the study of human society must, I claim, be admitted to an 
 adequate place in the curriculum of our universities. It is 
 not so many years ago since the professor of animal 
 biology and the biological laboratory were unknown to the 
 academic world. Think what that absence meant for the 
 knowledge of living forms — nay, for the general culture of 
 mankind, for it marks a date before Charles Darwin had 
 revolutionised our outlook on life ! Are we to assert that 
 this great biological movement, which has won its way to 
 equal rights in the academic fraternity, is to stop short 
 when it approaches the subject of man as a gregarious 
 animal } Is there no science of those vital factors which 
 may improve or impair, physically or mentally, the racial 
 qualities of future generations ? And if there be such a 
 science is it not the first duty of the universities to discover 
 and propound its laws ? 
 
 Now the genuine man of science will never admit that 
 any portion of nature, that any group of tnental or physical 
 phenomena is anomic, or without definite and discoverable
 
 8 THE GROUNDWORK OF EUGENICS 
 
 sequences. We do not despair of meteorology because the 
 method and the man that will make it a fairly precise science 
 is yet in the seeking. Astronomy sprang triumphant from 
 astrology, and the great Kepler himself, son of a woman 
 tried for witchcraft, started life by writing horoscopes. It 
 would be as reasonable to throw alchemy and Paracelsus 
 in the balance against modern chemical science, as to assert 
 that we must measure the possibilities of a study of human 
 society to-day by the sociology of yesterday and the social 
 science of the day before. 
 
 The difference is great and it is threefold. In the first 
 place it is a difference of mental training and intellectual 
 attitude. It is the difference between the student of hu- 
 manities and the student of science. Take a text-book of 
 political economy such as is put into the hands of every 
 student, for example that of President Walker; there is not 
 a single numerical association worked out, the verynumerical 
 tables given are purely hypothetical constructions of the 
 author introduced to illustrate the logomachy; the whole 
 reasoning is a reasoning about verbal notions, where we de- 
 mand a determination of the correlation of associated causes 
 based upon recorded experience. Social science followed 
 the earlier political economy, and provided verbose discus- 
 sion, where the first need was well-selected and well- recorded 
 observation. The fundamental change in our attitude is from 
 that of the essay writer to that of the scientific inquirer. Let 
 me illustrate my point by a concrete example. I take the 
 influence of the unhealthy trade of the father and the factory 
 occupation of the mother on the health and intelligence of 
 the children. Well, very much has been talked, very much 
 has been written, on that subject ; but the only real way to 
 answer the problem is by examining statistically the effect on 
 some 2o,oco or 30,000 children of the occupations of their
 
 THE GROUNDWORK OF EUGENICS 9 
 
 parents. This is precisely what Miss Elderton has recently 
 done, and I do not believe that any verbal discussion on what 
 ought to follow can be anything like as satisfactory as noting 
 what actually has happened. The next point is that even 
 when a few generations ago statistics were collected and 
 exhibited, there was no effective method of deducing the 
 kernel from them. Our power of interpreting statistics, of 
 measuring the exact degree of relationship between asso- 
 ciated phenomena, has enormously increased during the last 
 few decades. We have really to deal with the discovery of a 
 new calculus, which means not only for social problems, but 
 in many other fields, a very potent instrument for analysing 
 numerical records. The association of phenomena, the 
 interrelationship of quality and environment, the depend- 
 ence of characters on nurture and on nature can now be 
 measured with an ease and accuracy which were practically 
 unknown twenty years ago. 
 
 When we come to deal with man in the mass, to estimate 
 the characters of each group of the social body, to weigh 
 the amounts of virtue and of vice, of health and disease, of 
 intelligence and mental defect, it is not of the individual 
 but of the assemblage or array with certain qualities that we 
 have to treat. This array may consist of several hundreds 
 or thousands, and its common or ' recognition ' marks, be 
 they social or anti-social, its fertility, its dominance or decay 
 must form the subject of our study. 
 
 If you consider that point for a moment, namely, that we 
 propose to study the differentiated groups of mankind within 
 the same social body, to ascertain which of these differ- 
 entiated groups is, owing to its characteristics, the most 
 effective for this or that purpose, to determine not only its 
 rate of increase, but the extent to which its qualities are 
 transmitted to its offspring and modified by environment,
 
 lO THE GROUNDWORK OF EUGENICS 
 
 then you will perceive that what we are concerned with in 
 the main is the actuarial treatment of large numbers. You 
 will understand why great statistical advances had to be 
 made, before it became possible in an effective and not 
 merely periphrastic manner to study those agencies which 
 may improve or impair the racial qualities of future genera- 
 tions, in a word, to study eugenics. We may have to collect 
 our data from individual cases, but our results apply to the 
 differentiated group as a whole. In this sense the science 
 of eugenics is not personal — practical eugenics may touch 
 personal conduct — but the generalisations of the science 
 apply as I have endeavoured to indicate to groups of many 
 individuals, differentiated by this or that series of characters, 
 and subject to this or that nurture or environment. 
 
 This transition from declamatory assertion to statistical 
 proof is the characteristic feature of eugenics. And I need 
 to insist on it Jiere. It is not many weeks ago^ since the 
 folly of the Eugenics Laboratory was held up to the students 
 of this College because it was asserted to lay much stress 
 on nature and little on nurture, to emphasise heredity and 
 neglect environment. I have heard elementary teachers 
 assert that we were depriving them of \\\€\xraison d'etre, \v\\\c\\ 
 they told us was the conversion of bad material into good 
 by a fitting environment, by a judicious course of training 
 and nurture. Far be it from me to underrate without study 
 the effects of environment ; I hold no brief against environ- 
 ment ; I am not pledged to any formula of nature against 
 nurture. But I am unable to find that our declamatory 
 friends have themselves made any quantitative study of the 
 relative value of nature and nurture, and while they pro- 
 claimed our folly downstairs, there was comfortably lodged 
 
 ^ F"ebruary, 1909.
 
 THE GROUNDWORK OF EUGENICS II 
 
 in the pigeon-holes in the Laboratory upstairs a good deal 
 of evidence as to the relative intensity of the inheritance 
 and the environment factors. I refer to this point as an 
 illustration of what I mean, when I say that the method of 
 investigating the laws of human societies is changing from 
 the verbal to the statistical, and the problem of the parts 
 played by nature and nurture cannot be solved by appealing 
 vaguely to the excellent work of the schoolmaster or to the 
 admitted advantages of Peabody Buildings. 
 
 As we are here on the site of what is not unlikely to prove 
 one of the great battlefields of eugenics, I would illustrate, 
 by one example only, how the problem of nature versus 
 nurture has been prejudged. There is hardly a practical 
 text-book on ophthalmology which does not accept the 
 theory that the school is the hotbed for the production of 
 short-sight. If you endeavour to tracethis traditional attitude 
 to its source, you will find that the main authority for it is 
 the work of a German ophthalmologist, Cohn, who examined 
 the eyes of several thousand children, and recorded their 
 increasing myopia with increased number of years at school. 
 From this it is easy, but not logical, to assert that years of 
 school life produce myopia. It would be equally valid to 
 assert that the number of years a boy spends on arithmetic 
 lengthen his head, or, perhaps, more valid still to say that 
 the lengthening of his head produces myopia. Unfortun- 
 ately modern civilisation does not admit of our studying 
 several thousand children of civilised parents with normal 
 home environment, growing up without school, and ascer- 
 taining whether their short-sight would or would not 
 increase with growth. 
 
 But Cohn's original work gives us ground for pause ; he 
 has not only published a table giving the years at school, 
 but also a table giving the years of age in conjunction with
 
 12 THE GROUNDWORK OF EUGENICS 
 
 short-sight, and thence flow by modern statistical methods 
 two definite facts : — 
 
 (i) That myopia is more closely connected with years of 
 life than with the number of years at school. 
 
 (ii) That allowing for the high correlation between years 
 of life and years at school, then for a constant age there 
 is sensibly no relation between the intensity of short- 
 sightedness and the length of school life. 
 
 Myopia is thus quite sensibly related to age, but if age be 
 a measure of some continued and detrimental environment, 
 that environment does not appear to be school life, 
 
 I cite this widely accepted theory — that school is the 
 hotbed for the production of short-sightedness — as an 
 excellent illustration of the old and the new methods. 
 
 Miss Barrington, who has recently^ been investigating this 
 special subject of vision, has endeavoured tofind some feature 
 of home environment — the overcrowding, or the economic, 
 moral and physical surroundings of home and parentage — 
 which may be definitely associated with defective sight. 
 She fails to discover any substantial influence at all — the 
 intensity of environmental influence is insignificant as com- 
 pared with the strength we can demonstrate to exist in this 
 case for the factor of inheritance. 
 
 As I have said I hold no brief for nature against nurture, 
 but I do demand that their relative intensity shall be 
 measured, not theorised about. There will in the future be 
 big battles on this field of nurture and nature; I would ask 
 those of you who hold the lists to see that the combatants 
 shall fight not with opinions and words, but with facts, and, 
 what is more, properly interpreted facts. 
 
 Let us pass from the spirit and method of eugenics to 
 the third cause which has made it possible for a real study 
 
 ^ February, 1909.
 
 THE GROUNDWORK OF EUGENICS 1 3 
 
 of the laws of human society to be evolved now. That 
 cause is the great progress in the knowledge of heredity 
 which has been made by biology in recent years. With the 
 main features of that knowledge most of you are probably 
 familiar, but there are certain fundamental points of it 
 which bear so closely on the science of eugenics, that we 
 must linger briefly over them. Foremost among these is 
 the far-reaching distinction between the somatic and germ 
 cells of an individual. By aid of the latter and the latter 
 only, can, at least in the higher forms of life, a new individual 
 start, and directly from the germ cells of the parent arise in 
 the first place the germ cells of the new life. This hypo- 
 thesis of the continuity of the germ plasma has been 
 fundamental as a biological conception since it was pro- 
 pounded by Weismann, and its important bearing on 
 eugenics is manifest ; it does not involve but it is closely 
 allied to the principle of the non-inheritance of acquired 
 characters. Darwin thought it desirable to invent a vast 
 system of particles which pass from each body-cell and carry 
 its characters to the germ cells of the parent, whence they are 
 transmitted to the offspring. The actual manner of passage 
 from somatic to germ cell, whether by blood or nerve, has 
 never been settled, the 'pangene' has never been corporeally 
 located. In the more modern view the bodily resemblance 
 of parent and offspring arises, not because the somatic cells 
 of the one have contributed to the somatic cells of the other, 
 but because both are the product in the moiety of a con- 
 tinuous germ plasm. There is not the least doubt that this 
 explanation is simpler and more consonant with our present 
 knowledge. But once accepted, we see : — 
 
 (i) That the possibility of transmitting an acquired 
 character depends on the somatic cells being able to 
 affect the germ cells.
 
 14 THE GROUNDWORK OF EUGENICS 
 
 (ii) That the effect on the germ cells must be to produce 
 a character similar to that acquired by the original somatic 
 cells in a second somatic product. 
 
 Now there is no logical reason for a priori denying that 
 some modifications of the somatic cells may disturb the 
 equilibrium of the germ cells. The continuity of the germ 
 plasm is not equivalent to its uniqueness. The slightest 
 examination of a human family shows that all the germ 
 cells of one individual cannot be alike, the germ plasm con- 
 tains many possibilities. It is conceivable that modifying 
 the somatic cells as by excessive under- or over-nourish- 
 ment, some of these germ possibilities may be rendered 
 less probable or even eliminated — age might achieve 
 the same end. But without something corresponding 
 to Darwin's 'pangenes' it is inconceivable that change in 
 the somatic cells could produce an allied possibility in the 
 same direction in the germ cells. 
 
 The improbability of the somatic cells discharging 
 material character-bearers to be reabsorbed by the germ 
 cells is physiologically great, but it might have to be faced, 
 if there were any good evidence for the inheritance of 
 acquired characters. The evidence for this may be classed 
 as follows : — 
 
 {a) If acquired characters were inherited evolution would 
 have proceeded at a much greater rate. The reply to this is 
 that in the light of recent physical work there is no need 
 to quicken up evolution ; we now know that the biologists 
 and geologists were right and the physicists and mathe- 
 maticians wrong in the length they fixed for the life of the 
 earth. F'urther, if acquired characters were inherited, they 
 would certainly have involved the inheritance of acquired 
 degeneracy and defect as well as of acquired advantage, 
 and this would not have worked wholly for progression.
 
 THE GROUNDWORK OF EUGENICS 1 5 
 
 {b) Direct experiments^ 
 
 (i) The most famous are those of Brown-Sequard, who 
 is usually asserted to have produced epilepsy artificially 
 in guinea-pigs, and found it inherited in the offspring. The 
 actual experiments are by no means of this decisive char- 
 acter. The injured animals had among their young nineteen 
 who suffered from some defect of their nervous system, and 
 merely two out of these nineteen had a disease which might 
 be termed epilepsy. Westphal undertook twelve years later 
 a similar set of experiments and found one case in which 
 the two offspring of an epileptic pair were epileptic. Ober- 
 steinerin 1875 found in thirty-two young two cases in which 
 he believed the artificial epilepsy of the parents to be found 
 again in the offspring. In the fifteen following years he 
 failed to repeat the experiment, because he could not arti- 
 ficially create the epilepsy, which suggests that the first 
 material may have belonged to an epileptic stock. Sommer 
 in trying again to repeat such experiments came only to 
 negative results. It will be seen that the Brown-Sequard 
 experiments are wholly inconclusive and must remaifi so. 
 
 (ii) A second section of experimental work is that on 
 acquired immunity. Very small doses of poison gradually 
 administered produce an immunity against large doses. It 
 has been found that this immunity is transmitted to the 
 offspring and the offspring are for a limited time immune to 
 the poison. Important experiments of Ehrlich have been 
 claimed as evidence of the inheritance of acquired characters. 
 But there is a striking exception to the rule, immutiity of 
 the father produces no effect on the off spiking. It is only the 
 immunity of the mother which influences the offspring. The 
 view that the immunity is produced by ' antibodies ' in the 
 
 1 We are onlyconcernedwith those on mammals. In the case of plants 
 and insects there is at present much controversy and little firm ground.
 
 l6 THE GROUNDWORK OF EUGENICS 
 
 serum of the blood, depends upon other results as to im- 
 munity, but it suffices to explain without any inheritance of 
 acquired characters how the mother transmits to unborn 
 offspring immunity, as she is well known to be able to 
 transmit disease. 
 
 A direct experiment on a large scale is that of vaccination, 
 which, continued for many generations,has notproduced per- 
 manent immunity from small-pox in the race. Precisely the 
 same result occurs with diphtheria immunity. Werniche has 
 shown that an immune mother, but 7iot an iimimne father, 
 will produce immune children. The immunity thus acquired 
 may last as long as three months, but it disappears with the 
 grandchildren. 
 
 It would be as reasonable to speak of these cases as the 
 ' inheritance ' of acquired characters, as it would be to speak 
 of a newly vaccinated baby 'inheriting' from the calf an 
 immunity from small-pox. 
 
 (iii) Actual experiments have been made on mutilation- 
 inheritance. In 1887 Zacharias, at the gathering of German 
 Naturalists, appeared with two tailless kittens, the offspring 
 of a mother who had been curtailed. But the pedigree of 
 father and mother for many generations would have to be 
 carefully scanned in order that we might be clear as to ances- 
 try, and cats are not infrequently born tailless without a tail- 
 less family history. Weismann in twenty-two successive 
 generations of curtailed mice had 1592 tailed offspring and 
 none born in any degree tailless, and Bos and Von Rosenthal 
 have confirmed on both rats and mice these experiments^ 
 
 That unhealthy life, alcohol, excess of any kind, may cause 
 weakened somatic cells to react on the germ cells, and affect 
 the physique of the offspring, may be accepted, but this does 
 
 1 Martius {Pathogenesc i?iju'trr Krankheiten, 1909) gives a trenchant 
 criticism of all this evidence to which I am much indebted.
 
 THE GROUNDWORK OF EUGENICS 17 
 
 not involve the inheritance of acquired characters. Indeed 
 the whole of the proofs recently given that drunkenness is 
 found in the parents of idiots, epileptics, the insane and the 
 criminal, and of women who cannot suckle their own off- 
 spring, fail because they do not satisfactorily demonstrate 
 that the drunkenness was acquired by a normal stock, in 
 which no degeneracy was known before the parent took 
 to drink. If we start, not from the offspring of the alcoholic, 
 but from the alcoholic themselves, and work backwards, we 
 find in the majority of cases that they come of alcoholic, 
 epileptic or degenerate stocks. Hence while we are not 
 forced to deny that injured somatic cells may sometimes 
 degrade the germ cells, we must be very stringent in our 
 criticism of the type of proof habitually given of such 
 interaction. It would indeed seem that while Nature had 
 made it easy for an individual to modify his bodily cells, 
 she has made it very hard for the toxine in either blood or 
 lymph to reach the germ cells. As Martins puts it : 'The 
 individual stands in far greater danger than the race.' 
 
 It may not be out of place at this point to remind you of 
 the experiments by which Mr Galton endeavoured to test 
 Darwin's theory of pangenesis. He interchanged the blood 
 of two types of rabbits, but found absolutely no change in 
 the character of the offspring procreated after the inter- 
 change. This is strong, if not wholly conclusive, evidence 
 that no ' pangenes ' are carried by the blood. 
 
 {c) Lastly we have a great deal of loose and illusory 
 argument, which centres round the name of Herbert Spencer, 
 and which is not uncommonly used by educationalists, when 
 trying — which is quite unnecessary — to justify their work to 
 their fellow-men. There is a very apt tale about Herbert 
 Spencer, told by Mr Galton in his ' Merhories.' Herbert 
 Spencer once said in the presence of Huxley and others : 
 
 K. p. 2
 
 l8 THE GROUNDWORK OF EUGENICS 
 
 ' You fellows would little think that I wrote a tragedy when 
 I was young.' Huxley said promptly : ' I know what it 
 was about' Spencer declared it was impossible as he 
 had never shown or even spoken of it to any one before. 
 Huxley persisted. Spencer put him to the test. Huxley 
 replied: 'It was the history of a beautiful induction killed 
 by a nasty little fact.' 
 
 The beautiful induction, that human progress has been 
 accelerated by the acquired results of education inherited 
 by the offspring, is killed by the nasty little fact, that no 
 conclusive experiment on mammals which showed definite 
 action of somatic cells upon germ cells in an aUuned direction 
 has ever been made, and from the standpoint of modern 
 biology such action is not only nigh unthinkable, but must be 
 as largely harmful as useful. The race has evolved protec- 
 tion for itself from individual excess, by rendering the germ 
 cells largely independent of the somatic cells and their 
 changes. 
 
 It is not only at this point, but at another also, that 
 eugenics must receive help from modern biological 
 knowledge. Without pledging ourselves to any special 
 physiological theory of heredity, it is quite possible to 
 investigate the facts of heredity and to measure the rate of 
 inheritance of any character in man living in a community. 
 If we accept the theory of Mendel we reach in broad lines 
 the same theoretical results as the Biometric School has 
 reached from dealing solely with the statistics of populations, 
 namely, there is an average degree of resemblance between 
 parent and child, and this degree is lessened in geometrical 
 progression as we pass to grandparents and great- 
 grandparents. Now as eugenists our object is to determine 
 to what extent a differentiated class of the community 
 impresses its characters on its offspring, and the average
 
 THE GROUNDWORK OF EUGENICS 19 
 
 efifect is what we are seeking. It is not needful to pledge 
 ourselves to any one theory of inheritance. What we want to 
 ascertain are the proportions of children who will be born 
 able in able stocks and in dull stocks ; what are the pro- 
 portion of children who will develop insanity in sound and 
 in unsound stocks. The exact mechanism by which these 
 proportions are maintained is of vital interest to science, it 
 is not essential when we have to deal with mankind in the 
 mass and prescribe social treatment for differentiated classes. 
 
 In later lectures you will be shown how these problems 
 of inheritance have been approached from the statistical 
 standpoint. It will be indicated to you that with our present 
 knowledge we can safely affirm that not only physical but 
 psychical characters, and not only psychical characters but 
 morbid and pathological constitutions, are largely, and prob- 
 ably in absolutely equal degree, the product of inheritance. 
 Indeed were we the ' superman ' we could breed a race of 
 abnormally shy men, as we could breed a race of abnormally 
 tall men ; and we could breed a race in which six fingers 
 were the rule or one in which nearly every member was a 
 deaf-mute. 
 
 To sum up, then, this preliminary statement of what 
 eugenists may claim as bricks for the foundations of our 
 new structure : — 
 
 (i) We depart from the old sociology, in that we desert 
 verbal discussion for statistical facts. 
 
 (2) We apply the new methods of statistics which form 
 practically a new calculus. 
 
 (3) We start from three fundamental biological ideas : — 
 {a) That the relative weight of nature and nurture must 
 
 not a priori be assumed but must be scientifically measured ; 
 and thus far our experience is that nature d'ominates nurture, 
 and that inheritance is more vital than environment.
 
 20 THE GROUNDWORK OF EUGENICS 
 
 {b) That there exists no demonstrable inheritance of 
 acquired characters. Environment modifies the bodily 
 characters of the existing generation, but does not modify 
 the germ plasms from which the next generation springs. 
 At most environment can induce a selection of germ plasms 
 among the many provided determining which shall be 
 potential and which shall remain latent. 
 
 {c) That all human qualities are inherited in a marked 
 and probably equal degree. 
 
 If these ideas represent the substantial truth, you will see 
 how the whole function of the eugenist is theoretically 
 simplified. He cannot hope by nurture and by education 
 to create new germinal types. He can only hope by selective 
 environment to obtain the types most conducive to racial 
 welfare and to national progress. If we see this point 
 clearly and grasp it to the full, what a flood of light it 
 sheds on half the schemes for the amelioration of the 
 people, and half the projects of unthinking charity ! The 
 widely prevalent notion that bettered environment and im- 
 proved education mean o. progressive evolution of humanity 
 is found to be without any satisfactory scientific basis. 
 Improved conditions of life mean better health for the 
 existing population ; greater educational facilities mean 
 greater capacity for finding and using existing ability; they 
 do not connote that the next generation will be either 
 physically or mentally better than its parents. Selection 
 'i of parentage is the sole effective process known to science 
 by which a race can continuously progress. The rise and 
 fall of nations are in truth summed up in the maintenance 
 or cessation of that process of selection. Where the battle 
 is to the capable and the thrifty, where the dull and idle 
 have no chance to propagate their kind, there the nation will 
 progress, even if the land be sterile, the environment un-
 
 THE GROUNDWORK OF EUGENICS 21 
 
 friendly and educational facilities small. Give educational 
 facilities to all, limit the hours of labour to eight-a-day — 
 providing leisure to watch two football matches a week — 
 give a minimum wage with free medical advice, and yet 
 you will find that the unemployables, the degenerates and 
 the physical and mental weaklings increase rather than 
 decrease. Then when your society is on the down-grade, you 
 will perceive that in granting what each democracy must de- 
 mand and what each individual claims as asocial right, you 
 have made the grant in such a way that the old safeguard 
 for national welfare, the selection of parentage, has been 
 sacrificed, and that it has to be laboriously re-established by 
 new social sanctions. If these fail, then the collapse of your 
 civilisation follows, and it will be replaced by a barbarism 
 which pays little heed to or even rejoices in the cruelties of 
 uncontrolled natural selection. Loaves and the circus — - 
 wages for the unemployable and the public football match 
 to kill time — are as much signs now as of old that selection 
 is being suspended, and that suspension undoubtedly means 
 the rapid multiplication of the unfit at the expense of the fit. 
 
 The man in the street looks upon society and the nation as 
 a very stable structure, which continues from generation to 
 generation to exhibit the like social habits and the like 
 marked racial features. 
 
 But is this really a correct view ? I must confess that 
 when I approach any class of the nation and statistically 
 study it through two generations I fail to find this sup- 
 posed stability. Mentally and physically each stratum 
 of the community appears to be ever in flux. Nor I 
 think are the reasons for this change far to seek. They 
 will be found in the two demonstrable facts : — 
 
 (i) That a selective death-rate is always at work in human 
 societies ; and,
 
 22 THE GROUNDWORK OF EUGENICS 
 
 (ii) That the rate of reproduction of the various sections 
 of any community is widely different. 
 
 Man is a slow-thinking animal : he takes a long time to 
 grasp a new idea, and a still longer time to let it take its 
 place in the atmosphere of associations, which is the medium 
 through which he views his own relations to the universe, 
 and discriminates the social and the anti-social in conduct. 
 It is now fifty years since the Origin of Species was published. 
 We can now determine, and we have determined, the 
 measure of the selective death-rate in man. Death is not a 
 random archer, as he was thought to be of old. In from 50 
 to 75 per cent, of cases the bolt of death is not random, but 
 seeks the weak joint in the armour, the constitutional defect, 
 the predisposition, which we know in many cases to be an 
 inheritance. To the individual and his immediate friends 
 death and the crippling of activity by sickness and disease 
 appear as the harshest contrasts of natural law and human 
 hope and sympathy. So great is, and must be, the personal 
 feeling in this matter, that in fifty years we have scarcely 
 risen to the conception that death in its chief form — the 
 selective death-rate — is the principal factor which main- 
 tains and elevates racial fitness ; that the great function of 
 eliminating the weeds is maintained in the garden of human 
 life by the hand of death. Individually we shall never, per- 
 haps, be able to realise in this wastage of life the hand of 
 a beneficent gardener. But for those who would endeavour 
 to study human life from the outside, and judge what tends 
 to improve or to impair its efficiency, the selective death-rate 
 must remain a great and racially beneficent factor. There 
 are two lines which often ring in my ears, and which pre- 
 sumptuously I would have had the poet express somewhat 
 
 otherwise : — 
 
 So careful of the type she seems, 
 So careless of the single life.
 
 THE GROUNDWORK OF EUGENICS 23 
 
 The welfare of the type is the outcome not of the careless, 
 but of the heedful destruction of the single life. 
 
 It is not the repression of human emotions, but the 
 examination of life from a different — I will not venture to 
 say higher — aspect which leads some of us to-day to question 
 whether the many social changes which soften life to the 
 individual, which lessen the selective death-rate, tend to the 
 final welfare of humanity. The conception of the destruction 
 of the less fit as a beneficent factor of human growth must 
 become part of our mental atmosphere, we must look upon 
 it as a chief cause of the mental and physical growth of 
 mankind in the past, not as a blind and hostile natural 
 force carelessly crushing the single life, but as the source of 
 all that we value in the intellect and physique of the highest 
 type of mankind to-day. 
 
 The time may come when human society can undertake 
 for itself what natural selection has wrought for it in the 
 past ; but the suspension of the selective death-rate must go 
 step by step with reforms which shall consciously replace the 
 vigorous effectiveness of the old system. Therein lies the 
 purport of eugenics. For how does Nature work through 
 the selective death-rate .-' Simply and effectively. By the 
 death of those who cannot stand the strain of life, she 
 removes the weaker stock before it has had any, or its full 
 quotum, of offspring. When man knows better than at 
 present which are the qualities which fit him for his task and 
 for his environment, he may consciously undertake what 
 Nature has done for him by her selective death-rate; to 
 prepare him for this function is the true aim of the science 
 of eugenics. But when the eugenist realises the difficulties 
 in his way, when he comes in the future to sum up his success 
 and his failure, I fancy he will turn with a feeling akin to 
 gratitude to that blind force of Nature — the selective death-
 
 24 THE GROUNDWORK OF EUGENICS 
 
 rate — which led man in his younger days irresistibly along 
 the path of progress. There are religious faiths which look 
 upon pain as a divinely administered good — as a beneficial 
 discipline. May not something of the same kind be realised 
 by those who stand on the firm platform of evolutionary 
 science in the fiftieth year of its life ? Death, not the random 
 archer of mediaeval notion, but the skilful marksman whose 
 aim is planned, has been in the past, and may perhaps long 
 continue to be, the chief source of human progress as a whole. 
 On the martyrdom of men is built the triumph of mankind. 
 
 I have wandered somewhat from my point — the unstable 
 character of human society owing to the selective death-rate 
 — but I would impress upon you the fact that unless the 
 eugenist realises the vastness of the forces at present at 
 work moulding human life, he cannot hope to take definite 
 action — an action based upon firm knowledge — when he 
 comes to the criticism of present social tendencies. 
 
 The eugenist as far as lies in his power has to replace 
 the selective death-rate by a selective birth-rate. The past 
 has depended for progress on Natural Selection, can the 
 future depend for progress on Reproductive Selection ? My 
 aim to-day is to insist on the gigantic part these two forces 
 play in the evolution of human communities. 
 
 You may not unreasonably say that I have so far talked 
 much about the selective death-rate but given you no proof 
 that natural selection really plays a part in human develop- 
 ment. I gave the proof many years ago as a modest reply 
 to Lord Salisbury's famous Oxford address asserting that 
 nobody had seen Natural Selection at work. Of course no 
 biologist paid any attention to my proof at the time, and 
 it remained the special knowledge of biometricians, until 
 Professor Ploetz of Munich turned it up recently (1909) 
 and reasserted its correctness.
 
 THE GROUNDWORK OF EUGENICS 
 
 
 k ILLUSTRATION 
 
 OF NATURAL 
 
 SCLCCTION 
 
 45 
 
 X 
 
 IN MAN 
 
 
 ♦O 
 
 \s^ 
 
 
 
 3S 
 
 MEAN 313 0~~--— 2. 
 
 
 
 30 
 
 
 - " — — tr- 
 
 «. 
 
 2S 
 
 
 
 ^\ 
 
 20 
 
 
 
 \ 
 
 IS 
 
 
 
 \ 
 
 10 
 
 
 
 
 5 
 
 
 
 
 26 36 46 
 LENGTH OF 
 
 56 66 
 LIFE OF 
 
 76 86 
 FATHER 
 
 Fig. I 
 
 ILLUSTRATION OF NATURAL SELECTION IN MAN 
 
 Efizs 
 
 36 46 56 66 
 
 LENGTH OF LIFE OF MOTHER 
 
 Fig. 2
 
 Plate II 
 
 SELECTIVE DEATH RATE IN MAN 
 
 Fig. 3 
 
 PERCENTAGE 
 
 DEATHS 
 
 OF CHUOREN 
 
 UN DE R ? I 
 
 (female s ) 
 
 
 -^ 
 
 SELECTI VE 
 
 DEATH RATE 
 
 IN MA N . 
 
 
 70 
 
 
 MOTHERS S 
 
 DAUGHTERS 
 
 
 60 
 
 
 "»-^ 
 
 - - o 
 
 
 
 SO 
 
 MEAN 
 
 42 4 
 
 ^\ 
 
 
 
 40 
 
 
 
 •X 
 
 ^V^ 
 
 
 3 
 
 
 
 
 '•©- ■ 
 
 .^^0 
 
 2 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 19-29 
 
 29-39 39-49 
 
 49-59 59-69 
 
 69-79 7989 
 
 89 
 
 LENGTH OF LIFE OF MOTHER 
 
 Fig. 4
 
 THE GROUNDWORK OF EUGENICS 25 
 
 The measure of the selective death-rate is extraordinarily 
 simple. It consists in the fact that the inheritance of the 
 length of life between parent and offspring is found statis- 
 tically to be about one-third of the average inheritance of 
 physical characters in man. This can only be due to the 
 fact that the death of parent or of offspring in a certain 
 number of cases is due to random and not to constitutional 
 causes. 
 
 Let/ be the chance of death from a random, not a consti- 
 tutional source, then i — / is the chance of a selective death 
 in parent and i — / again of a selective death in the case 
 of an offspring, then^ 
 
 (i — py must equal about \ = "36 more exactly 
 .-. I -p = -e 
 and / = '40. In other words 60 per cent, of deaths are 
 selective. I put this result — tested from many series — quite 
 broadly, and concluded that 50 to 75 per cent, of deaths in 
 man were due to Natural Selection. I can bring this fact 
 home to you by Figs. 3 and 4 of Plate II. It is the same 
 matter looked at from another light. You will note the 
 steady decrease of the death-rate with the greater con- 
 stitutional strength of the parents. 
 
 In Table I, I have taken female children up to twenty- 
 one, Le., practically those that die before reproduction. You 
 will see that whenever constitutional defect involving early 
 death occurs in the parent, the children die at the appalling 
 rate of more than 70 per cent, before twenty-one. If the 
 parent be long-lived, then only 30 per cent, die early. My 
 data are from well-to-do Quaker stocks, and this death rate 
 is thus not 'the result of absence of care or of means of 
 livelihood. Professor Ploetz, who suggested this method 
 of examining the data, shows the san^e thing in two series 
 ^ Phil. Trans., vol. 192 A p. 277 ; Bioinei}-ika, vol. i. p. 74.
 
 26 
 
 THE GROUNDWORK OF EUGENICS 
 
 of his own, one of middle-class and the other of Royal 
 families (where no neglect can be supposed) \ His 
 
 TABLE I. INFLUENCE OF PHYSICAL CONSTITUTION 
 OF PARENTS ON THE DEATH-RATE OF THEIR 
 OFFSPRING. 
 
 A. Mothers and Daughters. 
 Age of Mother at Death. 
 
 Offspring 
 
 19-29 
 
 29-39 
 
 39-49 
 
 49-59 
 
 59-69 
 
 69-79 
 
 79-89 
 
 89 
 and 
 over 
 
 Totals 
 
 Died before 21 
 Survived 21 ... 
 
 36 
 13 
 
 122 
 63 
 
 123 
 93 
 
 III 
 
 115 
 180 
 
 162 
 291 
 
 91 
 283 
 
 22 
 64 
 
 782 
 1064 
 
 Totals ... 
 
 49 
 
 185 
 
 216 
 
 188 
 
 295 
 
 453 
 
 374 
 
 86 
 
 1846 
 
 Death-rate 
 
 73-5 
 
 65-9 
 
 56-9 
 
 59-0 
 
 39'o 
 
 35-8 
 
 24-3 
 
 25-6 
 
 42-4 
 
 B. Fathers and Daughters. 
 Age of Father at Death. 
 
 Offspring 
 
 24-34 
 
 34-44 
 
 44-54 
 
 54-64 
 
 64-74 
 
 74-84 
 
 84-94 
 
 94 
 and 
 over 
 
 Totals 
 
 Died before 21 
 
 Survived 21 ... 
 
 34 
 13 
 
 83 
 
 43 
 
 118 
 100 
 
 144 202 
 168 309 
 
 194 
 
 365 
 
 71 
 142 
 
 7 
 16 
 
 853 
 1 1 56 
 
 Totals ... 
 
 47 
 72-3 
 
 126 
 
 218 
 
 312 
 
 511 
 
 559 
 
 213 
 
 23 
 
 2009 
 
 Death-rate 
 
 65-9 
 
 54-1 
 
 46-2 
 
 39*5 347 
 
 33*3 30'4 
 
 42-5 
 
 In these Tables 19-29 means all ages greater than 19 and less 
 than 29 years.' 
 
 ^ See Archiv fiir Rassen- u. Gesellschafis-Biologie, Bd. VI. S. 33, 1909.
 
 THE GROUNDWORK OF EUGENICS 2/ 
 
 results are shown in Figs, i and 2 of Plate II. He 
 takes only the infantile mortality (under five years), and 
 he concludes that 60 per cent, at least of deaths are purely 
 selective. Such is the demonstration of the enormous part 
 which has been played by Natural Selection in man. Fifty 
 years after the publication of the Origin of Species, it is 
 purely idle to discuss, as our leading journal recently did, 
 whether Natural Selection has or has not application to 
 man. It has been demonstrably a really gigantic factor 
 of continuous change in human societies. 
 
 If I turn to my second factor of social instability — the 
 differential birth-rate — I must strive to convince you that 
 reproductive selection is only second to natural selection 
 in its vast reaching effects on human life. If society is to 
 reproduce itself without change from generation to genera- 
 tion, then, accepting the inheritance of human characters, 
 each subclass of the community endowed with its special 
 grade of intelligence or physique must be equally fertile. 
 If it is Jiot, then the successive generations will not be 
 identical, and can only be made identical owing to a 
 selective death-rate. 
 
 There are few persons who realise on how relatively small 
 a portion of each population the next generation depends. 
 We have first to consider that many never reach the repro- 
 ductive age at all. Here is the chief harvest of the selective 
 death-rate. In England of 1000 males born only 680 live 
 to be twenty, and of 1000 women only 708. Out of these 
 adults we have next to estimate how many never marry or 
 die without offspring. Here is the field not only of the 
 selective death-rate, but of the selective marriage-rate. It 
 is very difficult from any English statistics to determine how 
 many adults never marry. No inforrnation on this point is 
 asked in the death schedule for males ; it is asked, but im-
 
 28 THE GROUNDWORK OF EUGENICS 
 
 perfectly answered, in the case of the schedule for females. 
 From statistics of other countries^ it seems to me that about 
 another 20 per cent, to 30 per cent, of adults never marry. 
 To be on the safe side let us say that 50 to 6c per cent, of 
 those born leave no offspring. Lastly, among those who do 
 marry, how are the offspring distributed .-^ Clearly those 
 who have large families are responsible for a relatively 
 large proportion of the next generation. Fig. 5, Plate III, 
 illustrates the distribution of size of completed families in 
 Quaker stocks. You will notice at once that the mean 
 family is about 42 children. On the other hand about half 
 the families have less, half more, than 3'3 children. Let us 
 call families with less than 3*3 children subfertile and those 
 with more sjiperfcrtile. Then let us ask what relative 
 amount of offspring the 50 per cent, of subfertile and the 
 50 per cent, of superfertile parents produce. The dotted 
 curve gives the answer; it represents in percentages the total 
 number of children produced, and we find the 50 per cent, 
 of subfertile parents only provide about 25 per cent, of the 
 next generation whereas the superfertile parents give 75 
 per cent. This law is practically universal for mankind; 
 
 ^ One of the many grave defects of the English system of census 
 and registration returns is the absence of any record of civil condition 
 in the male death registration. The Registrar-General informs me that 
 the record of civil condition in the case of female deaths is worthless, 
 and that no useful return can be made from it. In the Argentine I find 
 that 60 percent, die unmarried. In the returns for 1861 and 1862 for 
 Scotland, 39,318 females died unmarried out of 65,467 deaths, again 
 almost exactly 60 per cent. Working on the last United States Census 
 I find that 5 1 per cent, of the population died unmarried, and on the 
 last two English Censuses and the Annual Reports that 48 per cent, 
 died unmarried. This indirect method of reaching the result is, how- 
 ever, not very satisfactory. We may, I think, conclude in round 
 numbers that 40 per cent, of the population dies before it reaches 
 twenty-one (see Figs. 3 and 4) and that probably another 20 per cent, 
 are never married.
 
 THE GROUNDWORK OF EUGENICS 
 
 CURVE OF FERTILITY IM MAN 
 ENGLISH. 
 
 Fig. 5 
 
 CURVES OF FERTItlTY IN 
 NEW SOUTH WALES
 
 Plate III 
 ILLUSTRATION OF EFFECT OF A 
 RELATIONSHIP BETWEEN FERTILITY 
 & INTELLIGENCE 
 
 
 < 
 
 r\ 
 
 A 
 
 7} 
 
 -X 
 
 /\ 
 
 r 
 
 -< 
 
 -J 
 
 / 
 
 
 — 
 
 H- 
 
 / 
 
 
 ^ 
 
 z 
 
 
 
 H 
 
 
 
 
 m 
 
 
 
 
 I- 
 r- 
 
 I/) 
 
 ^' 
 
 600 500 400 300 200 
 
 100 
 
 SCALE OF MENTACES. 
 
 Fig. 7 
 
 SCALE OF MENTACES 
 
 Fisr. 8
 
 THE GROUNDWORK OF EUGENICS 
 
 29 
 
 it has been confirmed for Denmark and for New South 
 Wales (Fig. 6, Plate III)^ Fifty per cent, of the married 
 population provide 75 per cent, of the next generation. 
 The same rule may be expressed in another way: 50 per 
 cent, of the next generation is produced by 25 per cent, of 
 the married population, or about 12 per cent, of all the 
 individuals born in the last generation provide half the 
 
 TABLE II. PROPORTION OF MATED INDIVIDUALS WHO 
 PRODUCE 50 PER CENT. OF THE NEXT GENERATION. 
 
 Species 
 
 Data 
 
 Percentage of Matings 
 
 M 
 
 an 
 
 English (Pearson) 
 Danish „ 
 New South Wales (Povvysj 
 Professional Classes 
 Domestic „ 
 Commercial „ 
 Industrial „ 
 Pastoral „ 
 
 
 25 
 25 
 
 23 
 
 23 
 
 23 [-Mean 25 
 
 25 
 
 2T) 
 
 Mice ... 
 Poultry ... 
 Swine ... 
 
 Horse ... 
 
 Weldon 
 
 Pearl 
 
 Rommel 
 
 T-, (Fecundity 
 
 Pearson jp^^tihty 
 
 35 
 36 
 39 
 
 41 
 
 25 
 
 next generation. This is not only a general law, but it is 
 practically true for each class in the community. This law 
 of mine holds in a lessened degee for other forms of life, 
 but it appears to reach its highest intensity in the case of 
 man (Table J I). And I believe that this is largely due to 
 certain artificial features of his civilisation. At least the 
 
 1 I am inclined to differ from Powys and consider that this diagram 
 indicates much artificial sterility.
 
 30 THE GROUNDWORK OF EUGENICS 
 
 case of the thoroughbred race horse, with its artificial 
 conditions, tends to confirm this view\ Be this as it may, 
 it is of vital importance for the eugenist to realise how 
 relatively small an element of human society is responsible 
 for the next generation -. 
 
 I want to emphasise this still more emphatically. Let 
 us assume that the 25 per cent, superfertile element in the 
 population has a lower average intelligence than the sub- 
 fertile 75 per cent. If you look at Fig. 7, Plate III, giving 
 the distribution of intelligence in the population, based upon 
 observations of about 4000 school-children and 1000 
 Cambridge graduates, you will see that 25 per cent, cor- 
 responds to about the range of slow, dull and mentally 
 defective. I have taken 100 units of intelligence, which I 
 term mentaces, to correspond to the range of the intellects 
 which fall between the specially able and the average man. 
 Now if we assume that the imbecile has zero intelligence, 
 you will find that the average man has about 300 or perhaps 
 rather more mentaces, and if we define genius to be about 
 'the one man in a thousand' level of ability, the genius has 
 some 600 or 700 mentaces. Now if we divide our popula- 
 tion at 25 per cent., the mean number of mentaces of this 
 rather slow and dull group is 173 and of the 75 per cent. 
 342, the average man having 300 mentaces. Now notice 
 what happens if the line between the superfertile and sub- 
 
 1 Judged from fecundity— the births to opportunity — the horse takes 
 its place properly among mammals. Judged by gross fertility it comes 
 close to man. 
 
 2 Critics have asked what Biometry has done during the fifteen 
 yearsof its existence to justify its claims as an instrument of biological 
 inquiry. It may be pertinently repHed, that to have demonstrated 
 that 12 per cent, of one generation in man produces 50 per cent, 
 of the next generation, and to have measured the intensity of natural 
 selection in man, would be quite sufficient claim, had it not done, as 
 it has done, much else.
 
 THE GROUNDWORK OF EUGENICS 3 1 
 
 fertile be that of intelligence. In the next generation there 
 will be 50 per cent, of lower and 50 per cent, of the higher 
 grade of intelligence, with an average for the whole com- 
 munity of 257 mentaces, a fall of 43 mentaces in the general 
 ability of the population ; in the next stage the superfertile 
 increase to 78 per cent, of the population and the average 
 ability has fallen to 210 mentaces ; in the third generation 
 the superfertile element has risen to 98 per cent, of the 
 whole and the average intelligence has fallen to 180 men- 
 taces. In Fig. 8, Plate III, this drop is represented by the 
 continual decrease in the areas of the circles, as the lower 
 intelligences with the higher fertility rapidly predominate. 
 You will note the progression from genius towards extreme 
 dullness. To impress this dwindling of a character owing 
 to reproductive selection on my readers, I will suppose as a 
 second illustration that cranial capacity is associated with 
 the subfertile group. Skull I to the right of Plate I 
 marks the average man and skulls II, III and IV the 
 degeneration which would follow in three generations. I do 
 not intend by this to assert that intelligence is proportional 
 to cranial capacity ; it is not. But I want to emphasise the 
 deterioration which must follow association between fertility 
 and inferiority in any racially valuable characteristic. Bear 
 those skulls in mind and you will not easily forget the rate of 
 degeneration which must follow any differentiation of the 
 intelligence or worth of the population into superfertile and 
 subfertile groups. What I have said here applies not only 
 to intelligence and cranial capacity but to every quality 
 which may be associated with a differentiated grade of 
 fertility. 
 
 I do not think anything can be more eugenicly impressive 
 than this principle that if fertility be correlated with any 
 character, the population must be unstable.
 
 32 THE GROUNDWORK OF EUGENICS 
 
 And now I want to make a somewhat remarkable ad- 
 mission. Not only in man but in other types of life, it is 
 extremely hard to find any character whatever which orgajti- 
 cally is markedly associated with fertility. Nature seems to 
 have effectually hindered living forms from undoing by 
 • reproductive selection her great achievements produced by 
 natural selection. It will be obvious to you that if one class 
 which died twice as fast as a second, yet produced three 
 times as many offspring, the increased fertility would more 
 than compensate for the selective death-rate. I do know 
 characters which are slightly related to fertility in man — 
 notably a character which I will term ' toughness of con- 
 stitution ' — and measurable by longevity — the husband 
 and wife who live to eighty will have on the average before 
 fifty years of age more children than the pair who only live 
 to sixty-five. But in Nature as a whole there is little relation 
 of fertility to any good or bad qualities of the individual. 
 
 Where, then, is the moral of my tale, if there be no organic 
 correlation between fertility and intelligence .-* The answer 
 lies in emphasising the word organic. What Nature has 
 avoided man has artificially produced. That is the kernel 
 of the whole matter for the science of eugenics. Approach 
 the problem as we will, the conclusion forced upon us is ever 
 the same, the physically inferior, the mentally slow are not 
 naturally more fertile than the stronger in body and mind, 
 but they are in our community to-day the more fertile, and 
 the process of deterioration I have exaggerated in that series 
 of skulls is in progress. The moment we suspend the full 
 vigour of natural selection, the moment we artificially corre- 
 late fertility with any defect of physique or intelligence, we 
 start that downward movement. To check this movement 
 I take to be the special function of practical eugenic action. 
 
 The correlation between fertility and unfitness will no
 
 THE GROUNDWORK OF EUGENICS 33 
 
 doubt be discussed more fully later in these lectures ; but I 
 should like to indicate how complex the problem is, and how 
 very difficult it is to obtain the facts one desires to know 
 from the manner in which returns are made in government 
 statistical offices. One has to turn to the countries of the 
 new world to get data which ought to be provided in this; 
 and then the social conditions are so different that we have 
 to allow for wide possibilities of divergence in our results. 
 
 If we look upon society as an organic whole, we must as- 
 sume that class distinctions are not entirely illusory ; that 
 certain families pursuedefiniteoccupations,because they have 
 a more or less specialised aptitude for them. In a rough sort 
 of way we may safely assume that the industrial classes are 
 not on the average as intelligent as the professional classes 
 and that the distinction is not entirely one of education. 
 
 Now the points we have to bear in mind are the following : 
 (i) the size of completed families ; (ii) the child mortality ; 
 (iii) the relative marriage-rate; (iv) the relative adult death- 
 rate for each class. Only when we know all these fully, shall 
 we be quite certain as to how the different classes in a com- 
 munity are altering. New South Wales ^ is one of the 
 few countries where such data are effectively recorded, and 
 Table III illustrates the nature of the successive allowances 
 to be made. The table refers to the size of families of the 
 various social classes at death of one or other parent. 
 
 The order of fertility is pastoral, industrial, commercial, 
 domestic and last professional, and although the percentage 
 child deaths are different in the different classes, yet the 
 net offspring or those that survive to fifteen are in the same 
 class order ; each industrial family has on an average half 
 a child more surviving than the average professional family. 
 So far the balance is still in favour of the industrial class. 
 1 Data from Powys, Biometrika, vol. iv. p. 233. 
 K. P. 3
 
 34 
 
 THE GROUNDWORK OF EUGENICS 
 
 But the next column shows you that this is not the whole 
 gain. The industrial classes are marrying at a far more 
 rapid rate than any otherclass ; five industrial marriages take 
 place for every four professional marriages and roughly for 
 
 TABLE III. FERTILITY WEIGHTS OF VARIOUS 
 SOCIAL CLASSES. 
 
 Completed Famh.ies. New South Wales. 
 
 Class 
 
 o 
 
 a o 
 
 Net 
 Offspring 
 
 
 Death-Rate 
 over 20 
 
 
 Pastoral 
 
 6-1 
 
 21-3 
 
 4-8 
 
 i8-2 
 
 127 
 
 •82 
 
 Industrial 
 
 5-2 
 
 27'0 
 
 3-8 
 
 40-5 
 
 227 
 
 1-28 
 
 Commercial 
 
 47 
 
 25-5 
 
 3-5 
 
 30-0 
 
 ^3-3 
 
 •98 
 
 Domestic 
 
 4-6 
 
 26-1 
 
 3"4 
 
 ■57 
 
 i6-6 
 
 •48 
 
 Professional 
 
 4-4 
 
 25-0 
 
 3-3 
 
 32-8 
 
 157 
 
 •98 
 
 Whole population 
 
 5-4 
 
 24-1 
 
 4-0 
 
 27-8 
 
 16-5 
 
 I 00 
 
 Completed Families. Denmark. 
 
 Pastoral 
 
 
 
 
 24-0 
 
 
 
 Industrial 
 
 5 "3 
 
 40 
 
 3-2 
 
 24-8 
 
 26-9 
 
 •81 
 
 Commercial 
 
 4-9 
 
 37 
 
 3"i 
 
 24-4 
 
 i6-i 
 
 1-29 
 
 Domestic 
 
 6-S 
 
 28 
 
 47 
 
 — 
 
 — 
 
 — 
 
 Professional 
 
 4-8 
 
 29 
 
 3"4 
 
 15-9 
 
 15-1 
 
 •98 
 
 Whole population 
 
 5"o 
 
 36 
 
 3-2 
 
 22-6 
 
 19-8 
 
 I 
 
 every two pastoral marriages. These rates are not true for 
 Europe. Westergaard and Rubin believe the marriage-rate 
 of the professional classes in Denmark to be one-third less 
 than that of the industrial classes. In our own country 
 I doubt whether the professional marriage-rate exceeds half 
 that of the industrial classes. Again, the small marriage-
 
 THE GROUNDWORK OF EUGENICS 35 
 
 rate of the pastoral classes would only apply to a country 
 where the agriculturist is largely a pioneer. So far, how- 
 ever, the race is markedly in favour of the industrial as 
 compared to the professional group. But here a new feature 
 comes in — the industrial classes may need a larger increase, 
 because their wastage is greater. In the next column I have 
 placed the death-rates for the several classes, considering 
 only adults over twenty. We find the death-rate is selective, 
 but it by no means compensates for the greater marriage- 
 rate and greater net birth-rate. In the last column I have 
 allowed for marriage and death-rates of the various classes, 
 and obtained what I term the fertility weight of the different 
 classes. The lesson to be learnt from this last column is 
 twofold : (i) that society is not a stable whole, the different 
 social classes multiply at very different rates, and (ii) that 
 society recruits itself from below, the rate of reproduction of 
 the industrial classes being 30 per cent, greater than that of 
 the professional classes. 
 
 We cannot apply these results directly to the state of 
 affairs in England. The marriage-rate of the professional 
 classes is much lower, and of the pastoral classes higher ; 
 the relatively low rate of those in domestic employment is 
 of course maintained, but the inadequate multiplication of 
 the domestic class is met by recruits, perhaps, as much from 
 the pastoral as from the industrial classes. My object, 
 however, is not to draw conclusions as to social classes, but 
 to point out that our principle of treatment must be the 
 same, whether we deal with social classes, intellectual grades, 
 or mentally or physically defective groups. We have in 
 each case to investigate their fertility weight as compared 
 with that of other types. The aim of the eugenist is to 
 enforce the principle, that society in every case must recruit 
 itself ' from above,' where ' above ' has now to be interpreted
 
 36 THE GROUNDWORK OF EUGENICS 
 
 not as referring to a social class level, but to the group with 
 the higher grade of the nationally desirable characteristic. 
 
 Thus far we have seen the large part played by selective 
 death-rates, selective birth-rates and selective marriage-rates 
 in determining the nature of the community, and in this you 
 may have realised how the science of eugenics is really em- 
 braced in the statistical or actuarial study of the growth of 
 human society. But a study of death and fertility would 
 carry us but little way, had we not some measure of how the 
 parental characters of each differentiated group are handed 
 down to their offspring. The results I am going to try and 
 impress upon you in conclusion to-day are based upon the 
 measurement of more than looo families, and, as will be 
 shown you in later lectures, may be considered closely true 
 not only for physical, not only for pathological, but for 
 mental characters. 
 
 Men and women do not mate at random ; our measure- 
 ments and observations show that for practically all char- 
 acters there is a selective mating, like tends in a sensible but 
 small degree to mate with like. Assuming this ' assortative 
 mating ' to exist, let us term exceptional the man or woman 
 who possesses more of a given character than every nineteen 
 persons out of twenty. Thus the tallest man in a random 
 twenty shall be called exceptionally tall ; the best in a 
 random class of twenty students exceptionally intelligent. 
 This is nothing more than a definition of what we will call 
 for the time being 'exceptional.' Now I found from our 
 study of the inheritance of human characters that fifty-two 
 marriages in 10,000 are of an exceptional man and woman, 
 9948 are of pairs of which neither or only one are excep- 
 tional. In the fifty-two exceptional marriages, exceptional 
 children are produced in the ratio of nearly 26 exceptional 
 to 26 unexceptional, or about half the children are excep-
 
 THE GROUNDWORK OF EUGENICS 37 
 
 tional. Of the 9948 unexceptional pairs, the ratio will be 
 474 exceptional to 9474 unexceptional children, or rather 
 less than one-twentieth of the children will be exceptional. 
 
 Thus while eighteen times as many exceptional children 
 will be born of commonplace as of exceptional parents, the 
 commonplace pairs only produce exceptional children at 
 one-tenth of the rate of the exceptional parents. That great 
 men are usually born of commonplace parents is only a 
 paradox, when we forget that commonplace pairs of parents 
 are 200 times as frequent as pairs of exceptional parents, and 
 that accordingly the small chance of an exceptional son 
 occurring to any commonplace pair is made up for by the 
 far greater number of such pairs. 
 
 The model photographed in Plate IV is an endeavour to 
 illustrate the point on which after all most eugenic inquiries 
 must turn. In the relatively small cube in the corner is a 
 profusion of individuals represented by black peas bearing 
 the character you want for national purposes. In the great 
 mass of the general population represented by the remainder 
 of the cube you see the sparsity of persons gifted with this 
 advantageous character. The bulk do not possess it, or 
 perhaps possess its opposite, a detrimental attribute. Even 
 in the general population the majority of these scattered 
 black peas would be found concentrated round the 
 exceptional corner. 
 
 Now let us fully grasp this — a minority in the communit)' 
 producing the coloured or desirable in profusion, a majority 
 producing the desirable very sparsely, and the colourless or 
 undesirable profusely. Grasp further that social and political 
 measures have reduced and will continue to reduce the 
 stringency of the selective death-rate between these two 
 classes. In the present state of social^ feeling we have only 
 one resource for remedying this — the selective birth-rate.
 
 38 THE GROUNDWORK OF EUGENICS 
 
 In the light of the recent work of Heron and others, can 
 we definitely place our fingers on any desirable social charac- 
 teristic to-day which has a selective birth-rate in its favour? 
 
 I believe that there is not a single character which makes 
 for national welfare, which can be shown definitely to be 
 favoured by a selective birth-rate at the present time. Social 
 conditions have allowed prepotent birth-rate to be associated 
 with a tabid and wilted stock. It would matter little were 
 not the same conditions suspending also the old selective 
 death-rate. Combined, these two factors must give in the 
 future the degeneracy I have endeavoured to illustrate 
 to-night. 
 
 These are the chief lessons which biological truths as 
 applied to man have to teach us. Natural fertility is not 
 markedly associated with good or bad characteristics. Given 
 a high birth-rate and a heavy death-rate Nature will preserve 
 and advance her human type with a cruelty to the individual, 
 which social feeling is too strong at present to permit of, 
 and political power too democratic to leave unchecked. But 
 when the selective death-rate is reduced, as far as legislation, 
 municipal hygiene, state support, medical progress and un- 
 limited charity can reduce it, then what means are left by 
 which mankind can consciously undertake the task which 
 Nature ha^ hitherto so ruthlessly carried out .'' 
 
 With the advance of civilisation the birth-rate as well 
 as the death-rate has become more and more artificial. 
 But it has become artificial in an individualistic and anti- 
 social way. The purport of eugenics is to study the causes 
 of this change, to create a strong public opinion, a new 
 moral sense on this cardinal factor of national welfare. 
 A progressive and imperial nation can only afford to be 
 kind to its weak in body or mind if that kindness 
 synchronises with the determination that each successive
 
 THE GROUNDWORK OF EUGENICS 39 
 
 generation shall be better born. We have to take social 
 customs as we find them. We must recognise to the full 
 that human fertility changes in highly civilised states from 
 the natural to the artificial phase. Such change led, in my 
 opinion, to the collapse of the great civihsations of the 
 ancient world. It will lead to the downfall of the great 
 civilisations of to-day, unless our clearer scientific insight 
 enables us to recognise, our more intense social spirit leads 
 us to stem in time, the ills which inevitably flow from the 
 suspension of the selective death-rate, and the artificial 
 creation of a cacogenic selective birth-rate. 
 
 It is a hundred years since Charles Darwin was born, fifty 
 years since he turned the search-light of natural selection on 
 the then dark mystery of living forms. It is fitting that 
 this anniversary year should proclaim that the knowledge 
 thus gained has a great practical application to the welfare 
 of human societies. The coping-stone is not of necessity 
 the most structurally important block in every building. 
 Yet in asserting that the science of eugenics forms the 
 coping-stone to the science of life, we shall emphasise that 
 the highest function of science is to be of direct practical 
 service to man, the lower functions are to discipline and 
 train his mind, to occupy and interest his leisure. The 
 fitness of eugenics as an academic branch of study lies not 
 alone in the training it requires, which carries us at the 
 same time into the new world of biological conceptions 
 and into the older world of accurate quantitative analysis. 
 It lies also in the groundwork it supplies for the treatment 
 of those great social problems, on the adequate and 
 expeditious solution of which lies, in the opinion of the 
 more thoughtful men and women of to-day, the main, if 
 not the sole, safeguard for future national progress. 
 
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