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APPLIED EUGENICS
BY
PAUL POPENOE
EDITOR OF THE JOURNAL OF HEREDITY (ORGAN OF
THE AMERICAN GENETIC ASSOCIATION),
WASHINGTON, D. C.
AND
ROSWELL HILL JOHNSON
PROFESSOR IN THE UNIVERSITY OF PITTSBURG
THE MACMILLAN COMPANY NEW YORK · BOSTON · CHICAGO · DALLAS
ATLANTA - SAN FRANCISCO
MACMILLAN & CO., LIMITED LONDON · BOMBAY · CALCUTTA MELBOURNE
THE MACMILLAN CO. OF CANADA, LTD. TORONTO
1918
_All rights reserved_
COPYRIGHT, 1918,
BY THE MACMILLAN COMPANY
Set up and electrotyped. Published October, 1918.
PREFACE
The science of eugenics consists of a foundation of biology and a
superstructure of sociology. Galton, its founder, emphasized both parts
in due proportion. Until recently, however, most sociologists have been
either indifferent or hostile to eugenics, and the science has been left
for the most part in the hands of biologists, who have naturally worked
most on the foundations and neglected the superstructure. Although we
are not disposed to minimize the importance of the biological part, we
think it desirable that the means of applying the biological principles
should be more carefully studied. The reader of this book will,
consequently, find only a summary explanation of the mechanism of
inheritance. Emphasis has rather been laid on the practical means by
which society may encourage the reproduction of superior persons and
discourage that of inferiors.
We assume that in general, a eugenically superior or desirable person
has, to a greater degree than the average, the germinal basis for the
following characteristics: to live past maturity, to reproduce
adequately, to live happily and to make contributions to the
productivity, happiness, and progress of society. It is desirable to
discriminate as much as possible between the possession of the germinal
basis and the observed achievement, since the latter consists of the
former plus or minus environmental influence. But where the amount of
modification is too obscure to be detected, it is advantageous to take
the demonstrated achievement as a tentative measure of the germinal
basis. The problem of eugenics is to make such legal, social and
economic adjustments that (1) a larger proportion of superior persons
will have children than at present, (2) that the average number of
offspring of each superior person will be greater than at present, (3)
that the most inferior persons will have no children, and finally that
(4) other inferior persons will have fewer children than now. The
science of eugenics is still young and much of its program must be
tentative and subject to the test of actual experiment. It is more
important that the student acquire the habit of looking at society from
a biological as well as a sociological point of view, than that he put
his faith in the efficacy of any particular mode of procedure.
The essential points of our eugenics program were laid down by Professor
Johnson in an article entitled "Human Evolution and its Control" in the
_Popular Science Monthly_ for January, 1910. Considerable parts of the
material in the present book have appeared in the _Journal of Heredity_.
Helpful suggestions and criticism have been received from several
friends, in particular Sewall Wright and O. E. Baker of the United States
Department of Agriculture.
PAUL POPENOE.
WASHINGTON, _June, 1918._
TABLE OF CONTENTS
PAGE
PREFACE v
INTRODUCTION BY EDWARD A. ROSS xi
CHAPTER
I. NATURE OR NURTURE? 1
II. MODIFICATION OF THE GERM-PLASM 25
III. DIFFERENCES AMONG MEN 75
IV. THE INHERITANCE OF MENTAL CAPACITIES 84
V. THE LAWS OF HEREDITY 99
VI. NATURAL SELECTION 116
VII. ORIGIN AND GROWTH OF THE EUGENICS MOVEMENT 147
VIII. DESIRABILITY OF RESTRICTIVE EUGENICS 167
IX. THE DYSGENIC CLASSES 176
X. METHODS OF RESTRICTION 184
XI. THE IMPROVEMENT OF SEXUAL SELECTION 211
XII. INCREASING THE MARRIAGE RATE OF THE SUPERIOR 237
XIII. INCREASE OF THE BIRTH-RATE OF THE SUPERIOR 255
XIV. THE COLOR LINE 280
XV. IMMIGRATION 298
XVI. WAR 318
XVII. GENEALOGY AND EUGENICS 329
XVIII. THE EUGENIC ASPECT OF SOME SPECIFIC REFORMS 352
TAXATION 352
BACK TO THE FARM MOVEMENT 355
DEMOCRACY 360
SOCIALISM 362
CHILD LABOR 368
COMPULSORY EDUCATION 369
VOCATIONAL GUIDANCE AND TRAINING 371
MINIMUM WAGE 374
MOTHER'S PENSIONS 375
HOUSING 376
FEMINISM 378
OLD AGE PENSIONS 384
SEX HYGIENE MOVEMENT 385
TRADES UNIONISM 388
PROHIBITION 389
PEDAGOGICAL CELIBACY 390
XIX. RELIGION AND EUGENICS 393
XX. EUGENICS AND EUTHENICS 402
APPENDIX A. OVARIAN TRANSPLANTATION 419
" B. DYNAMIC EVOLUTION 421
" C. THE "MELTING POT" 424
" D. THE ESSENCE OF MENDELISM 429
" E. USEFUL WORKS OF REFERENCE 436
" F. GLOSSARY 437
LIST OF ILLUSTRATIONS
FIGURE PAGE
1. Four Baby Girls at Once 6
2. The Effect of Nurture in Changing Nature 10
3. Height in Corn and Men 12
4. Why Men Grow Short or Tall 14
5. Bound Foot of a Chinese Woman 42
6. Defective Little Toe of a Prehistoric Egyptian 42
7. Effect of Lead as a "Racial Poison" 63
8. Distribution of 10-Year-Old School Children 76
9. Variation in Ability 77
10. Origin of a Normal Probability Curve 78
11. The "Chance" or "Probability" Form of Distribution 79
12. Probability Curve with Increased Number of Steps 80
13. Normal Variability Curve Following Law of Chance 80
14. Cadets Arranged to Show Normal Curve of Variability 82
15. Variation in Heights of Recruits to the American Army 82
16. How Do You Clasp Your Hands? 100
17. The Effect of Orthodactyly 102
18. A Family with Orthodactyly 102
19. White Blaze in the Hair 104
20. A Family of Spotted Negroes 104
21. A Human Finger-Tip 106
22. The Limits of Hereditary Control 106
23. The Distribution of Intelligence 106
24. The Twins whose Finger-Prints are Shown in Fig. 25 108
25. Finger-Prints of Twins 110
26. A Home of the "Hickory" Family 168
27. A Chieftain of the Hickory Clan 170
28. Two Juke Homes of the Present Day 172
29. Mongolian Deficiency 174
30. Feeble-Minded Men are Capable of Much Rough Labor 192
31. Feeble-Minded at a Vineland Colony 192
32. How Beauty Aids a Girl's Chance of Marriage 215
33. Intelligent Girls are Most Likely to Marry 216
34. Years Between Graduation and Marriage 217
35. The Effect of Late Marriages 218
36. Wellesley Graduates and Non-Graduates 242
37. Birth Rate of Harvard and Yale Graduates 266
38. Families of Prominent Methodists 263
39. Examining Immigrants at Ellis Island, New York, 303
40. Line of Ascent that Carries the Family Name 331
41. The Small Value of a Famous, but Remote, Ancestor 338
42. History of 100 Babies 344
43. Adult Morality 345
44. Influence of Mother's Age 347
45. The "Mean Man" of the Old White American Stock 425
46. The Carriers of Heredity 431
INTRODUCTION
The Great War has caused a vast destruction of the sounder portion of
the belligerent peoples and it is certain that in the next generation
the progeny of their weaker members will constitute a much larger
proportion of the whole than would have been the case if the War had not
occurred. Owing to this immeasurable calamity that has befallen the
white race, the question of eugenics has ceased to be merely academic.
It looms large whenever we consider the means of avoiding a stagnation
or even decline of our civilization in consequence of the losses the War
has inflicted upon the more valuable stocks. Eugenics is by no means
tender with established customs and institutions, and once it seemed
likely that its teachings would be left for our grandchildren to act on.
But the plowshare of war has turned up the tough sod of custom, and now
every sound new idea has a chance. Rooted prejudices have been leveled
like the forests of Picardy under gun fire. The fear of racial decline
provides the eugenist with a far stronger leverage than did the hope of
accelerating racial progress. It may be, then, that owing to the War
eugenic policies will gain as much ground by the middle of this century
as without it they would have gained by the end of the century.
This book could not have been written ten years ago because many of the
data it relies on were not then in existence. In view of inquiries now
going on, we may reasonably hope that ten years hence it will be
possible to make a much better book on the subject. But I am sure that
this book is as good a presentation as can be made of eugenics at its
present stage of development. The results of all the trustworthy
observations and experiments have been taken into account, and the
testing of human customs and institutions in the light of biological
principles tallies well with the sociology of our times.
I cannot understand how any conscientious person, dealing in a large way
with human life, should have the hardihood to ignore eugenics. This book
should command the attention not only of students of sociology, but, as
well, of philanthropists, social workers, settlement wardens, doctors,
clergymen, educators, editors, publicists, Y. M. C. A. secretaries and
industrial engineers. It ought to lie at the elbow of law-makers,
statesmen, poor relief officials, immigration inspectors, judges of
juvenile courts, probation officers, members of state boards of control
and heads of charitable and correctional institutions. Finally, the
thoughtful ought to find in it guidance in their problem of mating. It
will inspire the superior to rise above certain worldly ideals of life
and to aim at a family success rather than an individual success.
EDWARD ALSWORTH ROSS.
The University of Wisconsin
Madison, Wisconsin
July 1918.
APPLIED EUGENICS
CHAPTER I
NATURE OR NURTURE?
At the First Race Betterment Conference held at Battle Creek, Mich.,
many methods were suggested by which it was believed that the people of
America might be made, on the average, healthier, happier, and more
efficient. One afternoon the discussion turned to the children of the
slums. Their condition was pictured in dark colors. A number of
eugenists remarked that they were in many cases handicapped by a poor
heredity. Then Jacob Riis--a man for whom every American must feel a
profound admiration--strode upon the platform, filled with indignation.
"We have heard friends here talk about heredity," he exclaimed. "The
word has rung in my ears until I am sick of it. Heredity! Heredity!
There is just one heredity in all the world that is ours--we are
children of God, and there is nothing in the whole big world that we
cannot do in His service with it."
It is probably not beyond the truth to say that in this statement Jacob
Riis voiced the opinion of a majority of the social workers of this
country, and likewise a majority of the people who are faithfully and
with much self-sacrifice supporting charities, uplift movements, reform
legislation, and philanthropic attempts at social betterment in many
directions. They suppose that they are at the same time making the race
better by making the conditions better in which people live.
It is widely supposed that, although nature may have distributed some
handicaps at birth, they can be removed if the body is properly warmed
and fed and the mind properly exercised. It is further widely supposed
that this improvement in the condition of the individual will result in
his production of better infants, and that thus the race, gaining a
little momentum in each generation, will gradually move on toward
ultimate perfection.
There is no lack of efforts to improve the race, by this method of
direct change of the environment. It involves two assumptions, which are
sometimes made explicitly, sometimes merely taken for granted. These
are:
1. That changes in a man's surroundings, or, to use the more technical
biological term, in his nurture, will change the nature that he has
inherited.
2. That such changes will further be transmitted to his children.
Any one who proposes methods of race betterment, as we do in the present
book, must meet these two popular beliefs. We shall therefore examine
the first of them in this chapter, and the second in Chapter II.
Galton adopted and popularized Shakespere's antithesis of _nature_ and
_nurture_ to describe a man's inheritance and his surroundings, the two
terms including everything that can pertain to a human being. The words
are not wholly suitable, particularly since nature has two distinct
meanings,--human nature and external nature. The first is the only one
considered by Galton. Further, nurture is capable of subdivision into
those environmental influences which do not undergo much change,--e.g.,
soil and climate,--and those forces of civilization and education which
might better be described as culture. The evolutionist has really to
deal with the three factors of germ-plasm, physical surroundings and
culture. But Galton's phrase is so widely current that we shall continue
to use it, with the implications that have just been outlined.
The antithesis of nature and nurture is not a new one; it was met long
ago by biologists and settled by them to their own satisfaction. The
whole body of experimental and observational evidence in biology tends
to show that the characters which the individual inherits from his
ancestors remain remarkably constant in all ordinary conditions to which
they may be subjected. Their constancy is roughly proportionate to the
place of the animal in the scale of evolution; lower forms are more
easily changed by outside influence, but as one ascends to the higher
forms, which are more differentiated, it is found more and more
difficult to effect any change in them. Their characters are more
definitely fixed at birth.[1]
It is with the highest of all forms, Man, that we have now to deal. The
student in biology is not likely to doubt that the differences in men
are due much more to inherited nature than to any influences brought to
bear after birth, even though these latter influences include such
powerful ones as nutrition and education within ordinary limits.
But the biological evidence does not lend itself readily to summary
treatment, and we shall therefore examine the question by statistical
methods.[2] These have the further advantage of being more easily
understood; for facts which can be measured and expressed in numbers are
facts whose import the reader can usually decide for himself: he is
perfectly able to determine, without any special training, whether twice
two does or does not make four. One further preliminary remark: the
problem of nature vs. nurture can not be solved in general terms; a
moment's thought will show that it can be understood only by examining
one trait at a time. The problem is to decide whether the differences
between the people met in everyday life are due more to inheritance or
to outside influences, and these differences must naturally be examined
separately; they can not be lumped together.
To ask whether nature in general contributes more to a man than nurture
is futile; but it is not at all futile to ask whether the differences in
a given human trait are more affected by differences in nature than by
differences in nurture. It is easy to see that a verdict may be
sometimes given to one side, sometimes to the other. Albinism in
animals, for instance, is a trait which is known to be inherited, and
which is very slightly affected by differences of climate, food supply,
etc. On the other hand, there are factors which, although having
inherited bases, owe their expression almost wholly to outside
influences. Professor Morgan, for example, has found a strain of fruit
flies whose offspring in cold weather are usually born with
supernumerary legs. In hot weather they are practically normal. If this
strain were bred only in the tropics, the abnormality would probably not
be noticed; on the other hand, if it were bred only in cold regions, it
would be set down as one characterized by duplication of limbs. The
heredity factor would be the same in each case, the difference in
appearance being due merely to temperature.
Mere inspection does not always tell whether some feature of an
individual is more affected by changes in heredity or changes in
surroundings. On seeing a swarthy man, one may suppose that he comes of
a swarthy race, or that he is a fair-skinned man who has lived long in
the desert. In the one case the swarthiness would be inheritable, in the
other not. Which explanation is correct, can only be told by examining a
number of such individuals under critical conditions, or by an
examination of the ancestry. A man from a dark-skinned race would become
little darker by living under the desert sun, while a white man would
take on a good deal of tan.
The limited effect of nurture in changing nature is in some fields a
matter of common observation. The man who works in the gymnasium knows
that exercise increases the strength of a given group of muscles for a
while, but not indefinitely. There comes a time when the limit of a
man's hereditary potentiality is reached, and no amount of exercise will
add another millimeter to the circumference of his arm. Similarly the
handball or tennis player some day reaches his highest point, as do
runners or race horses. A trainer could bring Arthur Duffy in a few
years to the point of running a hundred yards in 9-3/5 seconds, but no
amount of training after that could clip off another fifth of a second.
A parallel case is found in the students who take a college examination.
Half a dozen of them may have devoted the same amount of time to it--may
have crammed to the limit--but they will still receive widely different
marks. These commonplace cases show that nurture has seemingly some
power to mold the individual, by giving his inborn possibilities a
chance to express themselves, but that nature says the first and last
word. Francis Galton, the father of eugenics, hit on an ingenious and
more convincing illustration by studying the history of twins.[3]
There are, everyday observation shows, two kinds of twins--ordinary
twins and the so-called identical twins. Ordinary twins are merely
brothers, or sisters, or brother and sister, who happen to be born two
at a time, because two ova have developed simultaneously. The fact that
they were born at the same time does not make them alike--they differ
quite as widely from each other as ordinary brothers and sisters do.
Identical twins have their origin in a different phenomenon--they are
believed to be halves of the same egg-cell, in which two growing-points
appeared at a very early embryonic stage, each of these developing into
a separate individual. As would be expected, these identical twins are
always of the same sex, and extremely like each other, so that sometimes
their own mother can not tell them apart. This likeness extends to all
sorts of traits:--they have lost their milk teeth on the same day in one
case, they even fell ill on the same day with the same disease, even
though they were in different cities.
Now Galton reasoned that if environment really changes the inborn
character, then these identical twins, who start life as halves of the
same whole, ought to become more unlike if they were brought up apart;
and as they grew older and moved into different spheres of activity,
they ought to become measurably dissimilar. On the other hand, ordinary
twins, who start dissimilar, ought to become more alike when brought up
in the same family, on the same diet, among the same friends, with the
same education. If the course of years shows that identical twins remain
as like as ever and ordinary twins as unlike as ever, regardless of
changes in conditions, then environment will have failed to demonstrate
that it has any great power to modify one's inborn nature in these
traits.
With this view, Galton collected the history of eighty pairs of
identical twins, thirty-five cases being accompanied by very full
details, which showed that the twins were really as nearly identical, in
childhood, as one could expect to find. On this point, Galton's
inquiries were careful, and the replies satisfactory. They are not,
however, as he remarks, much varied in character. "When the twins are
children, they are usually distinguished by ribbons tied around the
wrist or neck; nevertheless the one is sometimes fed, physicked, and
whipped by mistake for the other, and the description of these little
domestic catastrophes was usually given by the mother, in a phraseology,
that is sometimes touching by reason of its seriousness. I have one case
in which a doubt remains whether the children were not changed in their
bath, and the presumed A is not really B, and _vice versa_. In another
case, an artist was engaged on the portraits of twins who were between
three and four years of age; he had to lay aside his work for three
weeks, and, on resuming it, could not tell to which child the respective
likeness he had in hand belonged. The mistakes become less numerous on
the part of the mother during the boyhood and girlhood of the twins, but
are almost as frequent as before on the part of strangers. I have many
instances of tutors being unable to distinguish their twin pupils. Two
girls used regularly to impose on their music teacher when one of them
wanted a whole holiday; they had their lessons at separate hours, and
the one girl sacrificed herself to receive two lessons on the same day,
while the other one enjoyed herself from morning to evening. Here is a
brief and comprehensive account: 'Exactly alike in all, their
schoolmasters could never tell them apart; at dancing parties they
constantly changed partners without discovery; their close resemblance
is scarcely diminished by age."
[Illustration: FOUR BABY GIRLS AT ONCE
FIG. 1.--These quadruplet daughters were born to Mr. and Mrs.
F. M. Keys, Hollis, Okla., on July 4, 1915, and were seven months old
when the photograph was taken. Up to that time they had never had any
other nourishment than their mother's milk. Their weights at birth were
as follows (reading from left to right): Roberta, 4 pounds; Mona, 4-1/2
pounds; Mary, 4-1/4 pounds; Leota, 3-3/4 pounds. When photographed,
Roberta weighed 16 pounds and each of the others weighed 16-1/4. Their
aunt vouches for the fact that the care of the four is less trouble than
a single baby often makes. The mother has had no previous plural births,
although she has borne four children prior to these. Her own mother had
but two children, a son and a daughter, and there is no record of twins
on the mother's side. The father of the quadruplets is one of twelve
children, among whom is one pair of twins. It is known that twinning is
largely due to inheritance, and it would seem that the appearance of
these quadruplets is due to the hereditary influence of the father
rather than the mother. If this is the case, then the four girls must
all have come from one egg-cell, which split up at an early stage. Note
the uniform shape of the mouth, and the ears, set unusually low on the
head.]
"The following is a typical schoolboy anecdote:
"'Two twins were fond of playing tricks, and complaints were frequently
made; but the boys would never own which was the guilty one, and the
complainants were never certain which of the two it was. One head master
used to say he would never flog the innocent for the guilty, and the
other used to flog them both.'
"No less than nine anecdotes have reached me of a twin seeing his or her
reflection in the looking-glass, and addressing it in the belief that it
was the other twin in person.
"Children are usually quick in distinguishing between their parent and
his or her twin; but I have two cases to the contrary. Thus, the
daughter of a twin says:
"'Such was the marvelous similarity of their features, voice, manner,
etc., that I remember, as a child, being very much puzzled, and I think,
had my aunt lived much with us, I should have ended by thinking I had
two mothers!'
"In the other case, a father who was a twin, remarks of himself and his
brother:
"'We were extremely alike, and are so at this moment, so much so that
our children up to five and six years old did not know us apart.'
"Among my thirty-five detailed cases of close similarity, there are no
less than seven in which both twins suffered from some special ailment
or had some exceptional peculiarity. Both twins are apt to sicken at the
same time in no less than nine out of the thirty-five cases. Either
their illnesses, to which I refer, were non-contagious, or, if
contagious, the twins caught them simultaneously; they did not catch
them the one from the other."
Similarity in association of ideas, in tastes and habits was equally
close. In short, their resemblances were not superficial, but extremely
intimate, both in mind and body, while they were young; they were reared
almost exactly alike up to their early manhood and womanhood.
Then they separated into different walks of life. Did this change of the
environment alter their inborn character? For the detailed evidence,
one should consult Galton's own account; we give only his conclusions:
In many cases the resemblance of body and mind continued unaltered up to
old age, notwithstanding very different conditions of life; in others a
severe disease was sufficient to account for some change noticed. Other
dissimilarity that developed, Galton had reason to believe, was due to
the development of inborn characters that appeared late in life. He
therefore felt justified in broadly concluding "that the only
circumstance, within the range of those by which persons of similar
conditions of life are affected, that is capable of producing a marked
effect on the character of adults, is illness or some accident which
causes physical infirmity. The twins who closely resembled each other in
childhood and early youth, and were reared under not very dissimilar
conditions, either grow unlike through the development of natural [that
is, inherited] characteristics which had lain dormant at first, or else
they continue their lives, keeping time like two watches, hardly to be
thrown out of accord except by some physical jar."
Here was a distinct failure of nurture to modify the inborn nature. We
next consider the ordinary twins who were unlike from the start. Galton
had twenty such cases, given with much detail. "It is a fact," he
observes, "that extreme dissimilarity, such as existed between Jacob and
Esau, is a no less marked peculiarity of twins of the same sex than
extreme similarity." The character of the evidence as a whole may be
fairly conveyed by a few quotations:
(1) One parent says: "They have had _exactly the same nurture_ from
their birth up to the present time; they are both perfectly healthy and
strong, yet they are otherwise as dissimilar as two boys could be,
physically, mentally, and in their emotional nature."
(2) "I can answer most decidedly that the twins have been perfectly
dissimilar in character, habits, and likeness from the moment of their
birth to the present time, though they were nursed by the same woman,
went to school together, and were never separated until the age of
thirteen."
(3) "They have never been separated, never the least differently treated
in food, clothing, or education; both teethed at the same time, both had
measles, whooping cough, and scarlatina at the same time, and neither
has had any other serious illness. Both are and have been exceedingly
healthy, and have good abilities; yet they differ as much from each
other in mental cast as any one of my family differs from another."
(4) "Very dissimilar in mind and body; the one is quiet, retiring, and
slow but sure; good-tempered, but disposed to be sulky when
provoked;--the other is quick, vivacious, forward, acquiring easily and
forgetting soon; quick-tempered and choleric, but quickly forgiving and
forgetting. They have been educated together and never separated."
(5) "They were never alike either in mind or body, and their
dissimilarity increases daily. The external influences have been
identical; they have never been separated."
(6) "The two sisters are very different in ability and disposition. The
one is retiring, but firm and determined; she has no taste for music or
drawing. The other is of an active, excitable temperament; she displays
an unusual amount of quickness and talent, and is passionately fond of
music and drawing. From infancy, they have been rarely separated even at
school, and as children visiting their friends, they always went
together."
And so on. Not a single case was found in which originally dissimilar
characters became assimilated, although submitted to exactly the same
influences. Reviewing the evidence in his usual cautious way, Galton
declared, "There is no escape from the conclusion that nature prevails
enormously over nurture, when the differences of nurture do not exceed
what is commonly to be found among persons of the same rank in society
and in the same country."
This kind of evidence was a good start for eugenics but as the science
grew, it outgrew such evidence. It no longer wanted to be told, no
matter how minute the details, that "nature prevails enormously over
nurture." It wanted to know exactly how much. It refused to be satisfied
with the statement that a certain quantity was large; it demanded that
it be measured or weighed. So Galton, Karl Pearson and other
mathematicians devised means of doing this, and then Professor Edward L.
Thorndike of Columbia University took up Galton's problem again, with
more refined methods.
The tool used by Professor Thorndike was the coefficient of correlation,
which shows the amount of resemblance or association between any two
things that are capable of measurement, and is expressed in the form of
a decimal fraction somewhere between 0 and the unit 1. Zero shows that
there is no constant resemblance at all between the two things
concerned,--that they are wholly independent of each other, while 1
shows that they are completely dependent on each other, a condition that
rarely exists, of course.[4] For instance, the correlation between the
right and left femur in man's legs is .98.
Professor Thorndike found in the New York City schools fifty pairs of
twins of about the same age and measured the closeness of their
resemblance in eight physical characters, and also in six mental
characters, the latter being measured by the proficiency with which the
subjects performed various tests. Then children of the same age and sex,
picked at random from the same schools, were measured in the same way.
It was thus possible to tell how much more alike twins were than
ordinary children in the same environment.[5]
[Illustration: THE EFFECT OF NURTURE IN CHANGING NATURE
FIG. 2.--Corn of a single variety (Leaming Dent) grown in two
plots: at the left spaced far apart in hills, at the right crowded. The
former grows to its full potential height, the latter is stunted. The
size differences in the two plots are due to differences in environment,
the heredity in both cases being the same. Plants are much more
susceptible to nutritional influences on size than are mammals, but to a
less degree nutrition has a similar effect on man. Photograph from A. F.
Blakeslee.]
"If now these resemblances are due to the fact that the two members of
any twin pair are treated alike at home, have the same parental models,
attend the same school and are subject in general to closely similar
environmental conditions, then (1) twins should, up to the age of
leaving home, grow more and more alike, and in our measurements the
twins 13 and 14 years old should be much more alike than those 9 and 10
years old. Again (2) if similarity in training is the cause of
similarity in mental traits, ordinary fraternal pairs not over four or
five years apart in age should show a resemblance somewhat nearly as
great as twin pairs, for the home and school condition of a pair of the
former will not be much less similar than those of a pair of the latter.
Again, (3) if training is the cause, twins should show greater
resemblance in the case of traits much subject to training, such as
ability in addition or multiplication, than in traits less subject to
training, such as quickness in marking off the A's on a sheet of printed
capitals, or in writing the opposites of words."
The data were elaborately analyzed from many points of view. They showed
(1) that the twins 12-14 years old were not any more alike than the
twins 9-11 years old, although they ought to have been, if environment
has great power to mold the character during these so-called "plastic
years of childhood." They showed (2) that the resemblance between twins
was two or three times as great as between ordinary children of the same
age and sex, brought up under similar environment. There seems to be no
reason, except heredity, why twins should be more alike. The data showed
(3) that the twins were no more alike in traits subject to much training
than in traits subject to little or no training. Their achievement in
these traits was determined by their heredity; training did not
measurably alter these hereditary potentialities.
"The facts," Professor Thorndike wrote, "are easily, simply and
completely explained by one simple hypothesis; namely, that the nature
of the germ-cells--the conditions of conception--cause whatever
similarities and differences exist in the original natures of men, that
these conditions influence mind and body equally, and that in life the
differences in modification of mind and body produced by such
differences as obtain between the environments of present-day New York
City public school children are slight."
"The inferences," he says, "with respect to the enormous importance of
original nature in determining the behavior and achievements of any man
in comparison with his fellows of the same period of civilization and
conditions of life are obvious. All theories of human life must accept
as a first principle the fact that human beings at birth differ
enormously in mental capacities and that these differences are largely
due to similar differences in their ancestry. All attempts to change
human nature must accept as their most important condition the limits
set by original nature to each individual."
Meantime other investigators, principally followers of Karl Pearson in
England, were working out correlation coefficients in other lines of
research for hundreds of different traits. As we show in more detail in
Chapter IV, it was found, no matter what physical or mental trait was
measured, that the coefficient of correlation between parent and child
was a little less than .5 and that the coefficient between brother and
brother, or sister and sister, or brother and sister, was a little more
than .5. On the average of many cases the mean "nature" value, the
coefficient of direct heredity, was placed at .51. This gave another
means of measuring nurture, for it was also possible to measure the
relation between any trait in the child and some factor in the
environment. A specific instance will make this clearer.
Groups of school children usually show an appalling percentage of
short-sightedness. Now suppose it is suggested that this is because they
are allowed to learn to read at too early an age. One can find out the
age at which any given child did learn to read, and work out the
coefficient of correlation between this age and the child's amount of
myopia. If the relation between them is very close--say .7 or .8--it
will be evident that the earlier a child learns to read, the more
short-sighted he is as he grows older. This will not prove a relation of
cause and effect, but it will at least create a great suspicion. If on
the contrary the correlation is very slight, it will be evident that
early reading has little to do with the prevalance of defective vision
among school children. If investigators similarly work out all the other
correlations that can be suggested, finding whether there is any
regular relation between myopia and overcrowding, long hours of study,
general economic conditions at home, general physical or moral
conditions of parents, the time the child spends out of doors, etc., and
if no important relation is found between these various factors and
myopia, it will be evident that no factor of the environment which one
can think of as likely to cause the trouble really accounts for the poor
eyesight of school children.
[Illustration: HEIGHT IN CORN AND MEN
FIG. 3.--An unusually short and an unusually tall man,
photographed beside extreme varieties of corn which, like the men, owe
their differences in height indisputably to heredity rather than to
environment. No imaginable environmental differences could reverse the
positions of these two men, or of these two varieties of corn, the
heredity in each case being what it is. The large one might be stunted,
but the small one could not be made much larger. Photograph from A. F.
Blakeslee.]
This has actually been done,[6] and none of the conditions enumerated
has been found to be closely related to myopia in school children.
Correlations between fifteen environmental conditions and the goodness
of children's eyesight were measured, and only in one case was the
correlation as high as .1. The mean of these correlations was about
.04--an absolutely negligible quantity when compared with the common
heredity coefficient of .51.
Does this prove that the myopia is rather due to heredity? It would, by
a process of exclusion, if every conceivable environmental factor had
been measured and found wanting. That point in the investigation can
never be reached, but a tremendously strong suspicion is at least
justified. Now if the degree of resemblance between the prevalence of
myopia in parents and that in children be directly measured, and if it
be found that when the parent has eye trouble the child also has it,
then it seems that a general knowledge of heredity should lead to the
belief that the difficulty lies there, and that an environmental cause
for the poor vision of the school child was being sought, when it was
all the time due almost entirely to heredity. This final step has not
yet been completed in an adequate way,[7] but the evidence, partly
analogical, gives every reason to believe in the soundness of the
conclusion stated, that in most cases the schoolboy must wear glasses
because of his heredity, not because of overstudy or any neglect on the
part of his parents to care for his eyes properly during his childhood.
[Illustration: WHY MEN GROW SHORT OR TALL
FIG. 4.--Pedigree charts of the two men shown in the preceding
illustration. Squares represent men and circles women; figures
underlined denote measurement in stocking feet. It is obvious from a
comparison of the ancestry of the two men that the short one comes from
a predominantly short family, while the tall one gains his height
likewise from heredity. The shortest individual in the right-hand chart
would have been accounted tall in the family represented on the left.
After A. F. Blakeslee.]
The extent to which the intelligence of school children is dependent on
defective physique and unfavorable home environment is an important
practical question, which David Heron of London attacked by the methods
we have outlined. He wanted to find out whether the healthy children
were the most intelligent. One is constantly hearing stories of how the
intelligence of school children has been improved by some treatment
which improved their general health, but these stories are rarely
presented in such a way as to contribute evidence of scientific value.
It was desirable to know what exact measurement would show. The
intelligence of all the children in fourteen schools was measured in its
correlation with weight and height, conditions of clothing and teeth,
state of nutrition, cleanliness, good hearing, and the condition of the
cervical glands, tonsils and adenoids. It could not be found that mental
capacity was closely related to any of the characters dealt with.[8] The
particular set of characters measured was taken because it happened to
be furnished by data collected for another purpose; the various items
are suggestive rather than directly conclusive. Here again, the
correlation in most cases was less than .1, as compared with the general
heredity correlation of .5.
The investigation need not be limited to problems of bad breeding.
Eugenics, as its name shows, is primarily interested in "good breeding;"
it is particularly worth while, therefore, to examine the relations
between heredity and environment in the production of mental and moral
superiority.
If success in life--the kind of success that is due to great mental and
moral superiority--is due to the opportunities a man has, then it ought
to be pretty evenly distributed among all persons who have had favorable
opportunities, provided a large enough number of persons be taken to
allow the laws of probability full play. England offers a good field to
investigate this point, because Oxford and Cambridge, her two great
universities, turn out most of the eminent men of the country, or at
least have done so until recently. If nothing more is necessary to
ensure a youth's success than to give him a first-class education and
the chance to associate with superior people, then the prizes of life
ought to be pretty evenly distributed among the graduates of the two
universities, during a period of a century or two.
This is not the case. When we look at the history of England, as Galton
did nearly half a century ago, we find success in life to an unexpected
degree a family affair. The distinguished father is likely to have a
distinguished son, while the son of two "nobodies" has a very small
chance of becoming distinguished. To cite one concrete case, Galton
found[9] that the son of a distinguished judge had about one chance in
four of becoming himself distinguished, while the son of a man picked
out at random from the population had about one chance in 4,000 of
becoming similarly distinguished.
The objection at once occurs that perhaps social opportunities might
play the predominant part; that the son of an obscure man never gets a
chance, while the son of the prominent man is pushed forward regardless
of his inherent abilities. This, as Galton argued at length, can not be
true of men of really eminent attainments. The true genius, he thought,
frequently succeeds in rising despite great obstacles, while no amount
of family pull will succeed in making a mediocrity into a genius,
although it may land him in some high and very comfortable official
position. Galton found a good illustration in the papacy, where during
many centuries it was the custom for a pope to adopt one of his nephews
as a son, and push him forward in every way. If opportunity were all
that is required, these adopted sons ought to have reached eminence as
often as a real son would have done; but statistics show that they
reached eminence only as often as would be expected for nephews of great
men, whose chance is notably less, of course, than that of sons of great
men, in whom the intensity of heredity is much greater.
Transfer the inquiry to America, and it becomes even more conclusive,
for this is supposed to be the country of equal opportunities, where it
is a popular tradition that every boy has a chance to become president.
Success may be in some degree a family affair in caste-ridden England;
is it possible that the past history of the United States should show
the same state of affairs?
Galton found that about half of the great men of England had
distinguished close relatives. If the great men of America have fewer
distinguished close relatives, environment will be able to make out a
plausible case: it will be evident that in this continent of boundless
opportunities the boy with ambition and energy gets to the top, and that
this ambition and energy do not depend on the kind of family he comes
from.
Frederick Adams Woods has made precisely this investigation.[10] The
first step was to find out how many eminent men there are in American
history. Biographical dictionaries list about 3,500, and this number
provides a sufficiently unbiased standard from which to work. Now, Dr.
Woods says, if we suppose the average person to have as many as twenty
close relatives--as near as an uncle or a grandson--then computation
shows that only one person in 500 in the United States has a chance to
be a near relative of one of the 3,500 eminent men--provided it is
purely a matter of chance. As a fact, the 3,500 eminent men listed by
the biographical dictionaries are related to each other not as one in
500, but as one in five. If the more celebrated men alone be considered,
it is found that the percentage increases so that about one in three of
them has a close relative who is also distinguished. This ratio
increases to more than one in two when the families of the forty-six
Americans in the Hall of Fame are made the basis of study. If all the
eminent relations of those in the Hall of Fame are counted, they average
more than one apiece. Therefore, they are from five hundred to a
thousand times as much related to distinguished people as the ordinary
mortal is.
To look at it from another point of view, something like 1% of the
population of the country is as likely to produce a man of genius as is
all the rest of the population put together,--the other 99%.
This might still be due in some degree to family influence, to the
prestige of a famous name, or to educational advantages afforded the
sons of successful men. Dr. Woods' study of the royal families of Europe
is more decisive.[11]
In the latter group, the environment must be admitted--on the whole--to
be uniformly favorable. It has varied, naturally, in each case, but
speaking broadly it is certain that all the members of this group have
had the advantage of a good education, of unusual care and attention. If
such things affect achievement, then the achievements of this class
ought to be pretty generally distributed among the whole class. If
opportunity is the cause of a man's success, then most of the members of
this class ought to have succeeded, because to every one of royal blood,
the door of opportunity usually stands open. One would expect the heir
to the throne to show a better record than his younger brothers,
however, because his opportunity to distinguish himself is naturally
greater. This last point will be discussed first.
Dr. Woods divided all the individuals in his study into ten classes for
intellectuality and ten for morality, those most deficient in the
qualities being put in class 1, while the men and women of preëminent
intellectual and moral worth were put in class 10. Now if preëminent
intellect and morality were at all linked with the better chances that
an inheritor of succession has, then heirs to the throne ought to be
more plentiful in the higher grades than in the lower. Actual count
shows this not to be the case. A slightly larger percentage of
inheritors is rather to be found in the lower grades. The younger sons
have made just as good a showing as the sons who succeeded to power; as
one would expect if intellect and morality are due largely to heredity,
but as one would not expect if intellect and morality are due largely to
outward circumstances.
Are "conditions of turmoil, stress and adversity" strong forces in the
production of great men, as has often been claimed? There is no evidence
from facts to support that view. In the case of a few great commanders,
the times seemed particularly favorable. Napoleon, for example, could
hardly have been Napoleon had it not been for the French revolution. But
in general there have been wars going on during the whole period of
modern European history; there have always been opportunities for a
royal hero to make his appearance; but often the country has called for
many years in vain. Circumstances were powerless to produce a great man
and the nation had to wait until heredity produced him. Spain has for
several centuries been calling for genius in leadership in some lines;
but in vain. England could not get an able man from the Stuart line,
despite her need, and had to wait for William of Orange, who was a
descendant of a man of genius, William the Silent. "Italy had to wait
fifty years in bondage for her deliverers, Cavour, Garibaldi and Victor
Emmanuel."
"The upshot of it all," Dr. Woods decides, "is that, as regards
intellectual life, environment is a totally inadequate explanation. If
it explains certain characters in certain instances, it always fails to
explain many more, while heredity not only explains all, or at least
90%, of the intellectual side of character in practically every
instance, but does so best when questions of environment are left out of
discussion."
Despite the good environment almost uniformly present, the geniuses in
royalty are not scattered over the surface of the pedigree chart, but
form isolated little groups of closely related individuals. One centers
in Frederick the Great, another in Queen Isabella of Spain, a third in
William the Silent, and a fourth in Gustavus Adolphus. Furthermore, the
royal personages who are conspicuously low in intellect and morality are
similarly grouped. Careful study of the circumstances shows nothing in
the environment that would produce this grouping of genius, while it is
exactly what a knowledge of heredity leads one to expect.
In the next place, do the superior members of royalty have
proportionately more superior individuals among their close relatives,
as was found to be the case among the Americans in the Hall of Fame? A
count shows at once that they do. The first six grades all have about an
equal number of eminent relatives, but grade 7 has more while grade 8
has more than grade 7, and the geniuses of grade 10 have the highest
proportion of nearer relatives of their own character. Surely it cannot
be supposed that a relative of a king in grade 8 has on the average a
much less favorable environment than a relative of a king in grade 10.
Is it not fair, then, to assume that this relative's greater endowment
in the latter case is due to heredity?
Conditions are the same, whether males or females be considered. The
royal families of Europe offer a test case because for them the
environment is nearly uniformly favorable. A study of them shows great
mental and moral differences between them, and critical evidence
indicates that these differences are largely due to differences in
heredity. Differences of opportunity do not appear to be largely
responsible for the achievements of the individuals.
But, it is sometimes objected, opportunity certainly is responsible for
the appearance of much talent that would otherwise never appear. Take
the great increase in the number of scientific men in Germany during the
last half century, for example. It can not be pretended that this is due
to an increased birth-rate of such talent; it means that the growth of
an appreciation of scientific work has produced an increased amount of
scientific talent. J. McKeen Cattell has argued this point most
carefully in his study of the families of one thousand American men of
science (_Popular Science Monthly_, May, 1915). "A Darwin born in China
in 1809," he says, "could not have become a Darwin, nor could a Lincoln
born here on the same day have become a Lincoln had there been no Civil
War. If the two infants had been exchanged there would have been no
Darwin in America and no Lincoln in England." And so he continues,
urging that in the production of scientific men, at least, education is
more important than eugenics.
This line of argument contains a great deal of obvious truth, but is
subject to a somewhat obvious objection, if it is pushed too far. It is
certainly true that the exact field in which a man's activities will
find play is largely determined by his surroundings and education. Young
men in the United States are now becoming lawyers or men of science, who
would have become ministers had they been born a century or two ago. But
this environmental influence seems to us a minor one, for the man who is
highly gifted in some one line is usually, as all the work of
differential psychology shows, gifted more than the average in many
other lines. Opportunity decides in just what field his life work shall
lie; but he would be able to make a success in a number of fields.
Darwin born in America would probably not have become the Darwin we
know, but it is not to be supposed that he would have died a "mute,
inglorious Milton": it is not likely that he would have failed to make
his mark in some line of human activity. Dr. Cattell's argument, then,
while admissible, can not properly be urged against the fact that
ability is mainly dependent on inheritance.
We need not stop with the conclusion that equality of training or
opportunity is unable to level the inborn differences between men. We
can go even farther, and produce evidence to show that equality of
training _increases the differences_ in results achieved.
This evidence is obtained by measuring the effects of equal amounts of
exercise of a function upon individual differences in respect to
efficiency in it. Suppose one should pick out, at random, eight
children, and let them do problems in multiplication for 10 minutes.
After a number of such trials, the three best might average 39 correct
solutions in the 10 minutes, and the three poorest might average 25
examples. Then let them continue the work, until each one of them has
done 700 examples. Here is equality in training; does it lead to uniform
results?
Dr. Starch made the actual test which we have outlined and found that
the three best pupils gained on the average 45 in the course of doing
700 examples; while the three poorest gained only 26 in the same course
of time.
Similar tests have been made of school children in a number of
instances, and have shown that equality of training fails to bring about
equality of performance. All improve to some extent; but those who are
naturally better than their comrades usually become better still, when
conditions for all are the same. E. L. Thorndike gives[12] the following
tabular statement of a test he conducted:
THE EFFECT OF EQUAL AMOUNTS OF PRACTICE UPON INDIVIDUAL DIFFERENCES
IN THE MENTAL MULTIPLICATION OF A THREE-PLACE BY A THREE-PLACE
NUMBER
Amount done Percentage of
per unit of correct figures
time in answers
Hours of Practice
|
| First 5 Examples First 5 Examples
| | |
| | Last 5 or 10 | Last 5 or 10
| | Examples | Examples
| | | | |
| | | Gain | | Gain
Initial highest five individuals 5.1 85 147 61 70 78 18
" next five " 5.1 56 107 51 68 78 10
" " six " 5.3 46 68 22 74 82 8
" " six " 5.4 38 46 8 58 70 12
" " five " 5.2 31 57 26 47 67 20
" " one individual 5.2 19 32 13 100 82 -18
Similar results have been obtained by half a dozen other experimenters,
using the tests of mental multiplication, addition, marking A's on a
printed sheet of capitals, and the like. It would be a mistake to
conclude too much from experiments of such restricted scope; but they
all agree in showing that if every child were given an equal training,
the differences in these traits would nevertheless be very great.
And although we do not wish to strain the application of these results
too far, we are at least justified in saying that they strongly indicate
that inborn mediocrity can not be made into a high grade of talent by
training. Not every boy has a chance to distinguish himself, even if he
receives a good education.
We are driven back to the same old conclusion, that it is primarily
inborn nature which causes the achievements of men and women to be what
they are. Good environment, opportunity, training, will give good
heredity a chance to express itself; but they can not produce greatness
from bad heredity.
These conclusions are familiar to scientific sociologists, but they have
not yet had the influence on social service and practical attempts at
reform which they deserve. Many popular writers continue to confuse
cause and effect, as for example H. Addington Bruce, who contributed an
article to the _Century Magazine_, not long ago, on "The Boy Who Goes
Wrong." After alleging that the boy who goes wrong does so because he is
not properly brought up, Mr. Bruce quotes with approval the following
passage from Paul Dubois, "the eminent Swiss physician and philosopher:
"If you have the happiness to be a well-living man, take care not to
attribute the credit of it to yourself. Remember the favorable
conditions in which you have lived, surrounded by the relatives who
loved you and set you a good example; do not forget the close friends
who have taken you by the hand and led you away from the quagmires of
evil; keep a grateful remembrance for all the teachers who have
influenced you, the kind and intelligent school-master, the devoted
pastor; realize all these multiple influences which have made you what
you are. Then you will remember that such and such a culprit has not in
his sad life met with these favorable conditions; that he had a drunken
father or a foolish mother, and that he has lived without affection,
exposed to all kinds of temptation. You will then take pity upon this
disinherited man, whose mind has been nourished upon malformed mental
images, begetting evil sentiments such as immoderate desire or social
hatred."
Mr. Bruce indorses this kind of talk when he concludes, "The blame for
the boy who goes wrong does not rest with the boy himself, or yet with
his remote ancestors. It rests squarely with the parents who, through
ignorance or neglect, have failed to mold him aright in the plastic days
of childhood."
Where is the evidence of the existence of these plastic days of
childhood? If they exist, why do not ordinary brothers become as much
alike as identical twins? How long are we to be asked to believe, on
blind faith, that the child is putty, of which the educator can make
either mediocrity or genius, depending on his skill? What does the
environmentalist _know_ about these "plastic days"? If a boy has a
drunken father or foolish mother, does it not suggest that there is
something wrong with his pedigree? With such an ancestry, we do not
expect him to turn out brilliantly, no matter in what home he is brought
up. If a boy has the kind of parents who bring him up well; if he is,
as Dr. Dubois says, surrounded by relatives who love him and set him a
good example, we at once have ground for a suspicion that he comes of a
pretty good family, a stock characterized by a high standard of
intellectuality and morality, and it would surprise us if such a boy did
not turn out well. But he turns out well because what's bred in the bone
will show in him, if it gets any kind of a chance. It is his nature, not
his nurture, that is mainly responsible for his character.
CHAPTER II
MODIFICATION OF THE GERM-PLASM
Every living creature was at some stage of its life nothing more than a
single cell. It is generally known that human beings result from the
union of an egg-cell and a sperm-cell, but it is not so universally
understood that these germ-cells are part of a continuous stream of
germ-plasm which has been in existence ever since the appearance of life
on the globe, and which is destined to continue in existence as long as
life remains on the globe.
The corollaries of this fact are of great importance. Some of them will
be considered in this chapter.
Early investigators tended naturally to look on the germ-cells as a
product of the body. Being supposedly products of the body, it was
natural to think that they would in some measure reproduce the character
of the body which created them; and Darwin elaborated an ingenious
hypothesis to explain how the various characters could be represented in
the germ-cell. The idea held by him, in common with most other thinkers
of his period, is still held more or less unconsciously by those who
have not given particular attention to the subject. Generation is
conceived as a direct chain: the body produces the germ-cell which
produces another body which in turn produces another germ-cell, and so
on.
But a generation ago this idea fell under suspicion. August Weismann,
professor of zoölogy in the University of Freiburg, Germany, made
himself the champion of the new idea, about 1885, and developed it so
effectively that it is now a part of the creed of nearly every
biologist.
Weismann caused a general abandonment of the idea that the germ-cell is
produced by the body in each generation, and popularized the conception
of the germ-cell as a product of a stream of undifferentiated
germ-plasm, not only continuous but (potentially at least) immortal.
The body does not produce the germ-cells, he pointed out; instead, the
germ-cells produce the body.
The basis of this theory can best be understood by a brief consideration
of the reproduction of very simple organisms.
"Death is the end of life," is the belief of many other persons than the
Lotus Eaters. It is commonly supposed that everything which lives must
eventually die. But study of a one-celled animal, an Infusorian, for
example, reveals that when it reaches a certain age it pinches in two,
and each half becomes an Infusorian in all appearance identical with the
original cell. Has the parent cell then died? It may rather be said to
survive, in two parts. Each of these daughter cells will in turn go
through the same process of reproduction by simple fission, and the
process will be continued in their descendants. The Infusorian can be
called potentially immortal, because of this method of reproduction.
The immortality, as Weismann pointed out, is not of the kind attributed
by the Greeks to their gods, who could not die because no wound could
destroy them. On the contrary, the Infusorian is extremely fragile, and
is dying by millions at every instant; but if circumstances are
favorable, it _can_ live on; it is not inevitably doomed to die sooner
or later, as is Man. "It dies from accident often, from old age never."
Now the single-celled Infusorian is in many respects comparable with the
single-celled germ of the higher animals. The analogy has often been
carried too far; yet it remains indisputable that the germ-cells of men
reproduce in the same way--by simple fission--as the Infusorian and
other one-celled animals and plants, and that they are organized on much
the same plan. Given favorable circumstances, the germ-cell should be
expected to be equally immortal. Does it ever find these favorable
circumstances?
The investigations of microscopists indicate that it does--that
evolution has provided it with these favorable circumstances, in the
bodies of the higher animals. Let us recall in outline the early history
of the fertilized germ-cell, the _zygote_ formed by the union of ovum
and spermatozoön. These two unite to form a single cell, which is
essentially the same, physiologically, as other germ-cells. It divides
in two similar cells; these each divide; the resulting cells again
divide, and so the process continues, until the whole body--a fully
developed man,--has been produced by division and redivision of the one
zygote.
But the germ-cell is obviously different from most of the cells that
make up the finished product, the body. The latter are highly
differentiated and specialized for different functions--blood cells,
nerve cells, bone cells, muscle cells, and so on, each a single cell but
each adapted to do a certain work, for which the original,
undifferentiated germ-cell was wholly unfit. It is evident that
differentiation began to take place at some point in the series of
divisions, that is to say, in the development of the embryo.
Th. Boveri, studying the development of a threadworm, made the
interesting discovery that this differentiation began at the first
division. Of the two daughter-cells produced from the zygote, one
continued dividing at a very slow rate, and without showing any
specialization. Its "line of descent" produced only germ-cells. The
products of division of the other daughter-cell began to differentiate,
and soon formed all the necessary kinds of cells to make up the body of
the mature worm. In this body, the cells from the first daughter-cell
mentioned were inclosed, still undifferentiated: they formed the
germ-cells of the next generation, and after maturity were ready to be
ejected from the body, and to form new threadworms.
Imagine this process taking place through generation after generation of
threadworms, and one will realize that the germ-plasm was passed on
directly from one generation to the next; that in each generation it
gave rise to body-plasm, but that it did not at any time lose its
identity or continuity, a part of the germ-plasm being always set aside,
undifferentiated, to be handed on to the next generation.
In the light of this example, one can better understand the definition
of germ-plasm as "that part of the substance of the parents which does
not die with them, but perpetuates itself in their offspring." By
bringing his imagination into play, the reader will realize that there
is no limit to the backward continuity of this germ-plasm in the
threadworm. Granted that each species has arisen by evolution from some
other, this germ-cell which is observed in the body of the threadworm,
must be regarded as part of what may well be called a stream of
germ-plasm, that reaches back to the beginning of life in the world. It
will be equally evident that these is no foreordained limit to the
forward extension of the stream. It will continue in some branch, as
long as there are any threadworms or descendants of threadworms in the
world.
The reader may well express doubt as to whether what has been
demonstrated for the threadworm can be demonstrated for the higher
animals, including man. It must be admitted that in many of these
animals conditions are too unfavorable, and the process of embryology
too complicated, or too difficult to observe, to permit as distinct a
demonstration of this continuity of the germ-plasm, wherever it is
sought. But it has been demonstrated in a great many animals; no facts
which impair the theory have been discovered; and biologists therefore
feel perfectly justified in generalizing and declaring the continuity of
germ-plasm to be a law of the world of living things.
Focusing attention on its application to man, one sees that the race
must represent an immense network of lines of descent, running back
through a vast number of different forms of gradually diminishing
specialization, until it comes to a point where all its threads merge in
one knot--the single cell with which it may be supposed that life on
this globe began. Each individual is not only figuratively, but in a
very literal sense, the carrier of the heritage of the whole race--of
the whole past, indeed. Each individual is temporarily the custodian of
part of the "stuff of life"; from an evolutionary point of view, he may
be said to have been brought into existence, primarily to pass this
sacred heritage on to the next generation. From Nature's standpoint, he
is of little use in the world, his existence is scarcely justified,
unless he faithfully discharges this trust, passing on to the future
the "Lamp of Life" whose fire he has been created to guard for a short
while.
Immortality, we may point out in passing, is thus no mere _hope_ to the
parent: it is a _real possibility_. The death of the huge agglomeration
of highly specialized body-cells is a matter of little consequence, if
the germ-plasm, with its power to reproduce not only these body-cells,
but the mental traits--indeed, we may in a sense say the very soul--that
inhabited them, has been passed on. The individual continues to live, in
his offspring, just as the past lives in him. To the eugenist, life
everlasting is something more than a figure of speech or a theological
concept--it is as much a reality as the beat of the heart, the growth of
muscles or the activity of the mind.
This doctrine of the continuity of germ-plasm throws a fresh light on
the nature of human relationships. It is evident that the son who
resembles his father can not accurately be called a "chip off the old
block." Rather, they are both chips off the same block; and aside from
bringing about the fusion of two distinct strains of germ-plasm, father
and mother are no more responsible for endowing the child with its
characters except in the choice of mate, than is the child for "stamping
his impress" on his parents. From another point of view, it has been
said that father and son ought to be thought of as half-brothers by two
different mothers, each being the product of the same strain of paternal
germ-plasm, but not of the same strain of maternal germ-plasm.
Biologically, the father or mother should not be thought of as the
_producer_ of a child, but as the trustee of a stream of germ-plasm
which produces a child whenever the proper conditions arise. Or as Sir
Michael Foster put it, "The animal body is in reality a vehicle for ova
or sperm; and after the life of the parent has become potentially
renewed in the offspring, the body remains as a cast-off envelope whose
future is but to die." Finally to quote the metaphor of J. Arthur
Thomson, one may "think for a moment of a baker who has a very precious
kind of leaven; he uses much of this in baking a large loaf; but he so
arranges matters by a clever contrivance that part of the original
leaven is always carried on unaltered, carefully preserved for the next
baking. Nature is the baker, the loaf is the body, the leaven is the
germ-plasm, and each baking is a generation."
When the respective functions and relative importance, from a genetic
point of view, of germ-plasm and body-plasm are understood, it must be
fairly evident that the natural point of attack for any attempt at race
betterment which aims to be fundamental rather than wholly superficial,
must be the germ-plasm rather than the body-plasm. The failure to hold
this point of view has been responsible for the disappointing results of
much of the sociological theory of the last century, and for the fact
that some of the work now carried on under the name of race betterment
is producing results that are of little or no significance to true race
betterment.
On the other hand, it must be fairly evident, from the pains which
Nature has taken to arrange for the transmission of the germ-plasm from
generation to generation, that she would also protect it from injury
with meticulous care. It seems hardly reasonable to suppose that a
material of this sort should be exposed, in the higher animals at least,
to all the vicissitudes of the environment, and to injury or change from
the chance of outward circumstances.
In spite of these presumptions which the biologist would, to say the
least, consider worthy of careful investigation, the world is full of
well-intentioned people who are anxious to improve the race, and who in
their attempts to do so, wholly ignore the germ-plasm. They see only the
body-plasm. They are devoted to the dogma that if they can change the
body (and what is here said of the body applies equally to the mind) in
the direction they wish, this change will in some unascertainable way be
reproduced in the next generation. They rarely stop to think that man is
an animal, or that the science of biology might conceivably have
something to say about the means by which his species can be improved;
but if they do, they commonly take refuge, deliberately or
unconsciously, in the biology of half a century ago, which still
believed that these changes of the body could be so impressed on the
germ-plasm as to be continued in the following generation.
Such an assumption is made to-day by few who have thoroughly studied the
subject. Even those who still believed in what is conventionally called
"the inheritance of acquired characteristics" would be quick to
repudiate any such application of the doctrine as is commonly made by
most of the philanthropists and social workers who are proceeding
without seeking the light of biology. But the idea that these
modifications are inherited is so widespread among all who have not
studied biology, and is so much a part of the tradition of society, that
the question must be here examined, before we can proceed confidently
with our program of eugenics.
The problem is first to be defined.
It is evident that all characters which make up a man or woman, or any
other organism, must be either germinal or acquired. It is impossible to
conceive of any other category. But it is frequently hard to say in
which class a given character falls. Worse still, many persons do not
even distinguish the two categories accurately--a confusion made easier
by the quibble that _all_ characters must be acquired, since the
organism starts from a single cell, which possesses practically none of
the traits of the adult.
What we mean by an inborn character is one whose expression is due to
something which is present in the germ-plasm; one which is inherent and
due to heredity. An acquired character is simply a modification, due to
some cause external to the germ-plasm acting on an inborn character. In
looking at an individual, one can not always say with certainty which
characters are which; but with a little trouble, one can usually reach a
reliable decision. It is possible to measure the variation in a given
character in a group of parents and their children, in a number of
different environments; if the degree of resemblance between parent and
offspring is about the same in each case, regardless of the different
surroundings in which the children may have been brought up, the
character may properly be called germinal. This is the biometric method
of investigation. In practice, one can often reach a decision by much
simpler means: if the character is one that appears at birth, e.g.,
skin color, it is usually safe to assume that it is a germinal
character, unless there is some evident reason for deciding otherwise,
as in the case of a child born with some disease from which the mother
had been suffering for the previous few months. In general, it is more
difficult to decide whether a mental trait is germinal, than whether a
physical one is; and great care should be used in classification.
To make the distinction, one ought to be familiar with an individual
from birth, and to have some knowledge of the conditions to which he was
exposed, in the period between conception and birth,--for of course a
modification which takes place during that time is as truly an acquired
character as one that takes place after parturition. Blindness, for
example, may be an inborn defect. The child from conception may have
lacked the requisites for the development of sight. On the other hand,
it may be an acquired character, due to an ill-advised display of
patriotism on July 4, at some time during childhood; or even to
infection at the moment of birth. Similarly small size may be an inborn
character, due to a small-sized ancestry; but if the child comes of a
normal ancestry and is stunted merely because of lack of proper care and
food, the smallness is an acquired character. Deafness may be congenital
and inborn, or it may be acquired as the result, say, of scarlet fever
during childhood.
Now the inborn characters (excepting modifications _in utero_) are
admittedly heritable, for inborn characters must exist potentially in
the germ-plasm. The belief that acquired characters are also inherited,
therefore, involves belief that in some way the trait acquired by the
parent is incorporated in the germ-plasm of the parent, to be handed on
to the child and reappear in the course of the child's development. The
impress on the parental _body_ must in some way be transferred to the
parental _germ-plasm_; and not as a general influence, but as a specific
one which can be reproduced by the germ-plasm.
This idea was held almost without question by the biologists of the
past, from Aristotle on. Questionings indeed arose from time to time,
but they were vague and carried no weight, until a generation ago
several able men elaborated them. For many years, it was the question of
chief dispute in the study of heredity. The last word has not yet been
said on it. It has theoretical bearings of immense importance; for our
conception of the process of evolution will be shaped according to the
belief that acquired characters are or are not inherited. Herbert
Spencer went so far as to say, "Close contemplation of the facts
impresses me more strongly than ever with two alternatives--either that
there has been inheritance of acquired characters, or there has been no
evolution." But its practical bearings are no less momentous. Again to
quote Spencer: "Considering the width and depth of the effects which the
acceptance or non-acceptance of one or the other of these hypotheses
must have on our views of life, the question, Which of them is true?
demands beyond all other questions whatever the attention of scientific
men. A grave responsibility rests on biologists in respect of the
general question, since wrong answers lead, among other effects, to
wrong belief about social affairs and to disastrous social actions."
Biologists certainly have not shirked this "grave responsibility" during
the last 30 years, and they have, in our opinion, satisfactorily
answered the general question. The answer they give is not the answer
Herbert Spencer gave.
But the popular mind frequently lags a generation behind, in its grasp
of the work of science, and it must be said that in this case the
popular mind is still largely under the influence of Herbert Spencer and
his school. _Whether they know it or not_, most people who have not made
a particular study of the question still tacitly assume that the
acquirements of one generation form part of the inborn heritage of the
next, and the present social and educational systems are founded in
large part on this false foundation. Most philanthropy starts out
unquestioningly with the assumption that by modifying the individual for
the better, it will thereby improve the germinal quality of the race.
Even a self-styled eugenist asks, "Can prospective parents who have
thoroughly and systematically disciplined themselves, physically,
mentally and morally, transmit to their offspring the traits or
tendencies which they have developed?" and answers the question with the
astounding statement, "It seems reasonable to suppose that they have
this power, it being simply a phase of heredity, the tendency of like to
beget like."
The right understanding of this famous problem is therefore fraught with
the most important consequences to eugenics. The huge mass of
experimental evidence that has been accumulated during the last quarter
of a century has, necessarily, been almost wholly based on work with
plants and lower animals. Even though we can not attempt to present a
general review of this evidence, for which the reader must consult one
of the standard works on biology or genetics, we shall point out some of
the considerations underlying the problem and its solution.
In the first place, it must be definitely understood that we are dealing
only with specific, as distinguished from general, transmission. As the
germ-cells derive their nourishment from the body, it is obvious that
any cause profoundly affecting the latter might in that way exercise an
influence on the germ-cells; that if the parent was starved, the
germ-cells might be ill-nourished and the resulting offspring might be
weak and puny. There is experimental evidence that this is the case; but
that is not the inheritance of an acquired character. If, however, a
white man tanned by long exposure to the tropical sun should have
children who were brunettes, when the family stock was all blond; or if
men whose legs were deformed through falls in childhood should have
children whose legs, at birth, appeared deformed in the same manner;
then there would be a distinct case of the transmission of an acquired
characteristic. "The precise question," as Professor Thomson words it,
"is this: Can a structural change in the body, induced by some change in
use or disuse, or by a change in surrounding influence, affect the
germ-cells in such a _specific_ or representative way that the offspring
will through its inheritance exhibit, even in a slight degree, the
modification which the parent acquired?" He then lists a number of
current misunderstandings, which are so widespread that they deserve to
be considered here.
(1) It is frequently argued (as Herbert Spencer himself suggested) that
unless modifications are inherited, there could be no such thing as
evolution. Such pessimism is unwarranted. There _is_ abundant
explanation of evolution, in the abundant supply of germinal variations
which every individual presents.
(2) It is common to advance an _interpretation_ of some observation, in
support of the Lamarckian doctrine, as if it were a _fact_.
Interpretations are not facts. What is wanted are the facts; each
student has a right to interpret them as he sees fit, but not to
represent his interpretation as a fact. It is easy to find structural
features in Nature which _may be interpreted_ as resulting from the
inheritance of acquired characters; but this is not the same as to say
and to prove that they _have resulted_ from such inheritance.
(3) It is common to beg the question by pointing to the transmission of
some character that is not proved to be a modification. Herbert Spencer
cited the prevalence of short-sightedness among the "notoriously
studious" Germans as a defect due to the inheritance of an acquired
character. But he offered no evidence that this is an acquirement rather
than a germinal character. As a fact, there is reason to believe that
weakness of the eyes is one of the characteristics of that race, and
existed long before the Germans ever became studious--even at a time
when most of them could neither read nor write.
(4) The reappearance of a modification may be mistaken for the
transmission of a modification. Thus a blond European family moves to
the tropics, and the parents become tanned. The children who grow up
under the tropical sun are tanned from infancy; and after the
grandchildren or great-grandchildren appear, brown from childhood, some
one points to the case as an instance of permanent modification of
skin-color. But of course the children at the time of birth are as white
as their distant cousins in Europe, and if taken back to the North to be
brought up, would be no darker than their kinsmen who had never been in
the tropics. Such "evidence" has often been brought forward by careless
observers, but can deceive no one who inquires carefully into the facts.
(5) In the case of diseases, re-infection is often mistaken for
transmission. The father had pneumonia; the son later developed it;
ergo, he must have inherited it. What evidence is there that the son in
this case did not get it from an entirely different source? Medical
literature is heavily burdened with such spurious evidence.
(6) Changes in the germ-cells _along with_ changes in the body are not
relevant to this discussion. The mother's body, for example, is poisoned
with alcohol, which is present in large quantities in the blood and
therefore might affect the germ-cells directly. If the children
subsequently born are consistently defective it is not an inheritance of
a body character but the result of a direct modification of the
germ-plasm. The inheritance of an acquired modification of the body can
only be proved if some particular change made in the parent is inherited
as such by the child.
(7) There is often a failure to distinguish between the possible
inheritance of a particular modification, and the possible inheritance
of indirect results of that modification, or of changes correlated with
it. This is a nice but crucial point on which most popular writers are
confused. Let us examine it through a hypothetical case. A woman, not
herself strong, bears a child that is weak. The woman then goes in for
athletics, in order better to fit herself for motherhood; she
specializes on tennis. After a few years she bears another child, which
is much stronger and better developed than the first. "Look," some one
will say, "how the mother has transmitted her acquirement to her
offspring." We grant that her improved general health will probably
result in a child that is better nourished than the first; but that is a
very different thing from heredity. If, however, the mother had played
tennis until her right arm was over-developed, and her spine bent; if
these characteristics were nowhere present in the ancestry and not seen
in the first child; but if the second child were born with a bent spine
and a right arm of exaggerated musculature, we would be willing to
consider the case on the basis of the inheritance of an acquired
character. We are not likely to have such a case presented to us.
To put the matter more generally, it is not enough to show that _some_
modification in the parent results in _some_ modification in the child.
For the purposes of this argument there must be a similar modification.
(8) Finally, data are frequently presented, which cover only two
generations--parent and child. Indeed, almost all the data alleged to
show the inheritance of acquired characteristics are of this kind. They
are of little or no value as evidence. Cases covering a number of
generations, where a _cumulative_ change was visible, would be of
weight, but on the rare occasions when they are forthcoming, they can be
explained in some other way more satisfactorily than by an appeal to the
theory of Lamarck.[13]
If the evidence currently offered to support a belief in the inheritance
of acquired characters is tested by the application of these
"misunderstandings," it will at once be found that most of it
disappears; that it can be thrown out of court without further
formality. The Lamarckian doctrine is now held mainly by persons who
have either lacked training in the evaluation of evidence, or have never
examined critically the assumptions on which they proceed. Medical men
and breeders of plants or animals are to a large extent believers in
Lamarckism, but the evidence (if any) on which they rely is always
susceptible of explanation in a more reasonable way. It must not be
forgotten that some of the ablest intellects in the world have been
assidously engaged in getting at the truth in the case, during the last
half-century; and it is certainly worthy of consideration that not in a
single case has the transmission of an acquired body character ever
been proved beyond dispute. Those who still hold a belief in it (and it
is fair to say that some men of real ability are among that number) too
often do so, it is to be feared, because it is necessary for the support
of some theoretical doctrine which they have formulated. Certainly there
are few men who can say that they have carefully examined the evidence
in the case, and accept Lamarckism because the evidence forces them to
do so. It will be interesting to review the various classes of alleged
evidence, though we can cite only a few cases from the great number
available (most of them, however, dealing with plants or lower animals).
Nearly all the evidence adduced can be put in one of these four classes:
(1) Mutilations.
(2) Diseases.
(3) Results of use or disuse.
(4) Physico-chemical effects of environment.
The case in regard to mutilations is particularly clear cut and leaves
little room for doubt. The noses and ears of oriental women have been
pierced for generations without number, yet girls are still born with
these parts entire. Circumcision offers another test case. The evidence
of laboratory experiments (amputation of tails) shows no inheritance. It
may be said without hesitation that mutilations are not heritable, no
matter how many generations undergo them.
(2) The transmissibility of acquired diseases is a question involved in
more of a haze of ignorance and loose thinking. It is particularly
frequent to see cases of uterine infection offered as cases of the
inheritance of acquired characters. To use the word "heredity" in such a
case is unjustified. Uterine infection has no bearing whatever on the
question.
Taking an historical view, it seems fairly evident that if diseases were
really inherited, the race would have been extinct long ago. Of course
there are constitutional defects or abnormalities that are in the
germ-plasm and are heritable: such is the peculiar inability of the
blood to coagulate, which marks "bleeders" (sufferers from hemophilia, a
highly hereditary disease). And in many cases it is difficult to
distinguish between a real germinal condition of this sort, and an
acquired disease.
The inheritance of an acquired disease is not only inconceivable, in the
light of what is known about the germ-plasm, but there is no evidence to
support it. While there is most decidedly such a thing as the
inheritance of a tendency to or lack of resistance to a disease, it is
not the result of incidence of the disease on the parent. It is possible
to inherit a tendency to headaches or to chronic alcoholism; and it is
possible to inherit a lack of resistance to common diseases such as
malaria, small-pox or measles; but actually to inherit a zymotic disease
as an inherent genetic trait, is impossible,--is, in fact, a
contradiction of terms.
(3) When we come to the effects of use and disuse, we reach a much
debated ground, and one complicated by the injection of a great deal of
biological theorizing, as well as the presence of the usual large amount
of faulty observation and inference.
It will be admitted by every one that a part of the body which is much
used tends to increase in size, or strength, and similarly that a part
which is not used tends to atrophy. It is further found that such
changes are progressive in the race, in many cases. Man's brain has
steadily increased in size, as he used it more and more; on the other
hand, his canine teeth have grown smaller. Can this be regarded as the
inheritance of a long continued process of use and disuse? Such a view
is often taken, but the Lamarckian doctrine seems to us just as mystical
here as anywhere else, and no more necessary. Progressive changes can be
satisfactorily accounted for by natural selection; retrogressive changes
are susceptible of explanation along similar lines. When an organ is no
longer necessary, as the hind legs of a whale, for instance, natural
selection no longer keeps it at the point of perfection. Variation,
however, continues to occur in it. Since the organ is now useless,
natural selection will no longer restrain variation in such an organ,
and degeneracy will naturally follow, for of all the variations that
occur in the organ, those tending to loss are more numerous than those
tending to addition. If the embryonic development of a whale's hind leg
be compared to some complicated mechanical process, such as the
manufacture of a typewriter, it will be easier to realize that a trivial
variation which affected one of the first stages of the process would
alter all succeeding stages and ruin the final perfection of the
machine. It appears, then, that progressive degeneration of an organ can
be adequately explained by variation with the removal of natural
selection, and that it is not necessary or desirable to appeal to any
Lamarckian factor of an unexplainable and undemonstrable nature.
The situation remains the same, when purely mental processes, such as
instincts, are considered. Habit often repeated becomes instinctive, it
is said; and then the instinct thus formed by the individual is passed
on to his descendants and becomes in the end a racial instinct. Most
psychologists have now abandoned this view, which receives no support
from investigation. Such prevalence as it still retains seems to be
largely due to a confusion of thought brought about by the use of the
word "instinctive" in two different senses,--first literally and then
figuratively.
A persistent attempt has been made in America during recent years, by
C. L. Redfield, a Chicago engineer, to rehabilitate the theory of the
inheritance of the effects of use and disuse. He has presented it in a
way that, to one ignorant of biology, appears very exact and plausible;
but his evidence is defective and his interpretation of his evidence
fallacious. Because of the widespread publicity, Mr. Redfield's work has
received, we discuss it further in Appendix B.
Since the importance of hormones (internal secretions) in the body
became known, it has often been suggested that their action may furnish
the clue to some sort of an inheritance of modifications. The hormone
might conceivably modify the germ-plasm but if so, it would more likely
be in some wholly different way.
In general, we may confidently say that there is neither theoretical
necessity nor adequate experimental proof for belief that the results of
use and disuse are inherited.
(4) When we come to consider whether the effects of the environment are
inherited, we attack a stronghold of sociologists and historians.
Herbert Spencer thought one of the strongest pieces of evidence in this
category was to be found in the assimilation of foreigners in the United
States. "The descendants of the immigrant Irish," he pointed out, "lose
their Celtic aspect and become Americanised.... To say that 'spontaneous
variation,' increased by natural selection, can have produced this
effect, is going too far." Unfortunately for Mr. Spencer, he was basing
his conclusions on guesswork. It is only within the last few months that
the first trustworthy evidence on the point has appeared, in the careful
measurements of Hrdlicka who has demonstrated that Spencer was quite
wrong in his statement. As a fact, the original traits persist with
almost incredible fidelity. (Appendix C.)
In 1911, Franz Boas of Columbia University published measurements of the
head form of children of immigrants[14] which purported to show that
American conditions caused in some mysterious manner a change in the
shape of the head. This conclusion in itself would have been striking
enough, but was made more startling when he announced that the change
worked both ways: "The East European Hebrew, who has a very round head,
becomes more long-headed; the south Italian, who in Italy has an
exceedingly long head, becomes more short-headed"; and moreover this
potent influence was alleged to be a subtle one "which does not affect
the young child born abroad and growing up in American environment, but
which makes itself felt among the children born in America, even a short
time after the arrival of the parents in this country." Boas' work was
naturally pleasing to sociologists who believe in the reality of the
"melting-pot," and has obtained widespread acceptance in popular
literature. It has obtained little acceptance among his
fellow-anthropologists, some of whom allege that it is unsound because
of the faulty methods by which the measurements were made and the
incorrect standards used for comparison.
The many instances quoted by historians, where races have changed after
immigration, are to be explained in most cases by natural selection
under new conditions, or by interbreeding with the natives, and not as
the direct result of climate. Ellsworth Huntington, the most recent and
careful student of the effect of climate on man,[15] finds that climate
has a great deal of influence on man's energy, but as far as inherited
traits in general are concerned, he is constantly led to remark how
little heredity is capable of being changed.
Most members of the white race have little toes that are partly
atrophied, and considerably deformed. In many cases one of the joints
has undergone ankylosis--that is, the bones have coalesced. It is
confidently alleged that this is due to the inheritance of the effects
of wearing tight shoes through many centuries. When it is found that the
prehistoric Egyptians, who knew not tight shoes, suffered from the same
defect in a similar degree, one's confidence in this kind of evidence is
much diminished.
The retrogression of the little toe in man is probably to be explained
like the degeneration of the hind leg of the whale, as a result of the
excess of deteriorating variations which, when not eliminated by natural
selection, lead to atrophy. Since man began to limit the use of his feet
to walking on the ground, the little toe has had much less value to him.
The feet of Chinese women offer another illustration along this line.
Although they have been tightly bound for many generations, no deformity
is apparent in the feet of girl babies.
Breeders are generally of the opinion that good care and feed bestowed
on their stock produce results in succeeding generations. This is in a
way true, but it is due merely to the fact that the offspring get better
nourishment and therefore a better start in life. The changes in breeds,
the increase in milk yield, and similar facts, often explained as due to
inheritance of acquired characters, are better explained as the results
of selection, sometimes conscious, sometimes quite unconscious.
[Illustration: BOUND FOOT OF A CHINESE WOMAN
FIG. 5.--For centuries the feet of upper class women, and many
lower class women, in China have been distorted in this manner; but
their daughters have perfect feet when born.]
[Illustration: DEFECTIVE LITTLE TOE OF A PREHISTORIC EGYPTIAN
FIG. 6.--The above illustration shows the foot of a prehistoric
Egyptian who is estimated to have lived about 8000 B. C. The last joint
of the little toe had entirely disappeared, and careful dissection
leaves no doubt that it was a germinal abnormality, such as is
occasionally seen to-day, and not the result of disease. It is,
therefore, evident that the degeneration of man's little toe must be
ascribed to some more natural cause than the wearing of shoes for many
generations. Photograph from Dr. Gorgy Sobhy, School of Medicine,
Cairo.]
The question of inherited immunity to diseases, as the result of
vaccination or actual illness from them, has appeared in the controversy
in a number of forms, and is a point of much importance. It is not yet
clear, partly because the doctors disagree as to what immunity is. But
there is no adequate evidence that an immunity to anything can be
created and transmitted through the germ-plasm to succeeding
generations.
In short, no matter what evidence we examine, we must conclude that
inheritance of acquired bodily characters is not a subject that need be
reckoned with, in applied eugenics.
On the other hand, there is a possible indirect influence of
modifications, which may have real importance in man. If the individual
is modified in a certain way, in a number of generations, even though
such a modification is not transmitted to his descendants, yet its
continued existence may make possible, the survival of some germinal
variation bearing in the same direction, which without the protecting
influence of the pre-existing modification, would have been swamped or
destroyed.
Finally, it should be borne in mind that even if physical and mental
characters acquired during a man's lifetime are not transmitted, yet
there is a sort of transmission of acquired characters which has been of
immense importance to the evolution of the race. This is the so-called
"inheritance" of the environment; the passing on from one generation to
the next of the achievements of the race, its accumulated social
experience; its civilization, in short. It is doubtful whether any
useful end is gained by speaking of this continuance of the environment
as "heredity;" it certainly tends to confuse many people who are not
used to thinking in biological terms. Tradition is the preferable term.
There is much to be said in favor of E. B. Poulton's
definition,--"Civilization in general is the sum of those contrivances
which enable human beings to advance independently of heredity."
Whatever wisdom, material gain, or language is acquired by one
generation may be passed on to the next. As far as the environment is
concerned, one generation stands on the shoulders of its predecessor.
It might simplify the task of eugenics if the same could be said of
biological heredity. But it can not. Each generation must "start from
scratch."
In August Weismann's words, the development of a function in offspring
begins at the point where it _began_ in his parents, not at the point
where it _ended_ in them. Biological improvement of the race (and such
improvement greatly fosters all other kinds) must be made through a
selective birth-rate. There is no short-cut by way of euthenics, merely.
We must now consider whether there is any direct way of impairing good
heredity. It is currently believed that there are certain substances,
popularly known as "racial-poisons," which are capable of affecting the
germ-plasm adversely and permanently in spite of its isolation and
protection. For example, the literature of alcoholism, and much of the
literature of eugenics, abounds with statements to the effect that
alcohol _originates_ degeneracy in the human race.
The proof or disproof of this proposition must depend in the last
analysis on direct observation and carefully controlled experiments. As
the latter cannot be made feasibly on man, a number of students have
taken up the problem by using small animals which are easily handled in
laboratories. Many of these experiments are so imperfect in method that,
when carefully examined, they are found to possess little or no value as
evidence on the point here discussed.
Hodge, Mairet and Combemale, for example, have published data which
convinced them that the germ-plasm of dogs was injured by the
administration of alcohol. The test was the quality of offspring
directly produced by the intoxicated animals under experiment. But the
number of dogs used was too small to be conclusive, and there was no
"control": hence these experiments carry little weight.
Ovize, Fêrê and Stockard have shown that the effect of alcohol on hen's
eggs is to produce malformed embryos. This, however, is a case of
influencing the development of the individual, rather than the
germ-plasm. Evidence is abundant that individual development can be
harmed by alcohol, but the experiments with eggs are not to the point
of our present purpose.
Carlo Todde and others have carried out similar experiments on cocks.
The conclusions have in general been in favor of injury to the
germ-plasm, but the experiments were inadequate in extent.
Laitinen experimented on rabbits and guinea pigs, but he used small
doses and secured only negative results.
Several series of experiments with rats indicate that if the dosage is
large enough, the offspring can be affected.
Nice, using very small numbers of white mice, subjected them not only to
alcohol, but to caffein, nicotin, and tobacco smoke. The fecundity of
all these sets of mice was higher than that of the untreated ones used
as control; all of them gained in weight; of 707 young, none was
deformed, none stillborn, and there was only one abortion. The young of
the alcoholized mice surpassed all others in growth. The dosage Nice
employed was too small, however, to give his experiment great weight.
At the University of Wisconsin, Leon J. Cole has been treating male
rabbits with alcohol and reports that "what appear to be decisive
results have already been obtained. In the case of alcoholic poisoning
of the male the most marked result has been a lessening of his
efficiency as a sire, the alcohol apparently having had some effect on
the vitality of his spermatozoa." His experiment is properly planned and
carried out, but so far as results have been made public, they do not
appear to afford conclusive evidence that alcohol originates degeneracy
in offspring.
The long-continued and carefully conducted experiment of Charles R.
Stockard at the Cornell Medical College is most widely quoted in this
connection. He works with guinea-pigs. The animals are intoxicated
daily, six days in the week, by inhaling the fumes of alcohol to the
point where they show evident signs of its influence; their condition
may thus be compared to that of the toper who never gets "dead drunk"
but is never entirely sober. Treatment of this sort for a period as long
as three years produces no apparent bad effect on the individuals; they
continue to grow and become fat and vigorous, taking plenty of food and
behaving in a normal manner in every particular. Some of them have been
killed from time to time, and all the tissues, including the
reproductive glands, have been found perfectly normal. "The treated
animals are, therefore, little changed or injured so far as their
behavior and structure goes. Nevertheless, the effects of the treatment
are most decidedly indicated by the type of offspring to which they give
rise, whether they are mated together or with normal individuals."
Before the treatment is begun, every individual is mated at least once,
to demonstrate its possibility of giving rise to sound offspring. The
crucial test of the influence of alcohol on the germ-cells is, of
course, the mating of a previously alcoholized male with a normal,
untreated female, in a normal environment.
When the experiment was last reported,[16] it had covered five years and
four generations. The records of 682 offspring produced by 571 matings
were tabulated, 164 matings of alcoholized animals, in which either the
father, mother, or both were alcoholic, gave 64, or almost 40%, negative
results or early abortions, while only 25% of the control matings failed
to give full-term litters. Of the 100 full-term litters from alcoholic
parents 18% contained stillborn young and only 50% of all the matings
resulted in living litters, while 47% of the individuals in the litters
of living young died soon after birth. In contrast to this record 73% of
the 90 control matings gave living litters and 84% of the young in these
litters survived as normal, healthy animals.
"The mating records of the descendants of the alcoholized guinea pigs,
although they themselves were not treated with alcohol, compare in some
respects even more unfavorably with the control records than do the
above data from the directly alcoholized animals." The records of the
matings in the second filial generation "are still worse, higher
mortality and more pronounced deformities, while the few individuals
which have survived are generally weak and in many instances appear to
be quite sterile even though paired with vigorous, prolific, normal
mates."
We do not minimize the value of this experiment, when we say that too
much weight has been popularly placed on its results. Compare it with
the experiment with fowls at the University of Maine, which Raymond
Pearl reports.[17] He treated 19 fowls with alcohol, little effect on
the general health being shown, and none on egg production. From their
eggs 234 chicks were produced; the average percentage of fertility of
the eggs was diminished but the average percentage of hatchability of
fertile eggs was increased. The infant mortality of these chicks was
smaller than normal, the chicks were heavier when hatched and grew more
rapidly than normal afterwards. No deformities were found. "Out of 12
different characters for which we have exact quantitative data, the
offspring of treated parents taken as a group are superior to the
offspring of untreated parents in 8 characters," in two characters they
are inferior and in the remaining two there is no discernible
difference. At this stage Dr. Pearl's experiment is admittedly too
small, but he is continuing it. As far as reported, it confirms the work
of Professor Nice, above mentioned, and shows that what is true for
guinea pigs may not be true for other animals, and that the amount of
dosage probably also makes a difference. Dr. Pearl explains his results
by the hypothesis that the alcohol eliminated the weaker germs in the
parents, and allowed only the stronger germs to be used for
reproduction.
Despite the unsatisfactory nature of much of the alleged evidence, we
must conclude that alcohol, when given in large enough doses, may
sometimes affect the germ-plasm of some lower animals in such a way as
to deteriorate the quality of their offspring. This effect is probably
an "induction," which does not produce a permanent change in the bases
of heredity, but will wear away in a generation or two of good
surroundings. It must be remembered that although the second-generation
treated males of Dr. Stockard's experiment produced defective offspring
when mated with females from similarly treated stock, they produced
normal offspring when mated with normal females. The significance of
this fact has been too little emphasized in writings on "racial
poisons." If a normal mate will counteract the influence of a "poisoned"
one, it is obvious that the probabilities of danger to any race from
this source are much decreased, while if only a small part of the race
is affected, and mates at random, the racial damage might be so small
that it could hardly be detected.
There are several possible explanations of the fact that injury is found
in some experiments but not in others. It may be, as Dr. Pearl thinks,
that only weak germs are killed by moderate treatment, and the strong
ones are uninjured. And it is probable (this applies more particularly
to man) that the body can take care of a certain amount of alcohol
without receiving any injury therefrom; it is only when the dosage
passes the "danger point" that the possibility of injury appears. As to
the location of this limit, which varies with the species, little is
known. Much more work is needed before the problem will be fully cleared
up.
Alcohol has been in use in parts of the world for many centuries; it was
common in the Orient before the beginning of historical knowledge. Now
if its use by man impairs the germ-plasm, then it seems obvious that the
child of one who uses alcohol to a degree sufficient to impair his
germ-plasm will tend to be born inferior to his parent. If that child
himself is alcoholic, his own offspring will suffer still more, since
they must carry the burden of two generations of impairment. Continuing
this line of reasoning over a number of generations, in a race where
alcohol is freely used by most of the population, one seems unable to
escape from the conclusion that the effects of this racial poison, if it
be such, must necessarily be cumulative. The damage done to the race
must increase in each generation. If the deterioration of the race could
be measured, it might even be found to grow in a series of figures
representing arithmetical progression.
It seems impossible, with such a state of affairs, that a race in which
alcohol was widely used for a long period of time, could avoid
extinction. At any rate, the races which have used alcohol longest ought
to show great degeneracy--unless there be some regenerative process at
work constantly counteracting this cumulative effect of the racial
poison in impairing the germ-plasm.
Such a proposition at once demands an appeal to history. What is found
in examination of the races that have used alcohol the longest? Have
they undergone a progressive physical degeneracy, as should be expected?
By no means. In this particular respect they seem to have become
stronger rather than weaker, as time went on; that is, they have been
less and less injured by alcohol in each century, as far as can be told.
Examination of the history of nations which are now comparatively sober,
although having access to unlimited quantities of alcohol, shows that at
an earlier period in their history, they were notoriously drunken; and
the sobriety of a race seems to be proportioned to the length of time in
which it has had experience of alcohol. The Mediterranean peoples, who
have had abundance of it from the earliest period recorded, are now
relatively temperate. One rarely sees a drunkard among them, although
many individuals in them would never think of drinking water or any
other non-alcoholic beverage. In the northern nations, where the
experience of alcohol has been less prolonged, there is still a good
deal of drunkenness, although not so much as formerly. But among nations
to whom strong alcohol has only recently been made available--the
American Indian, for instance, or the Eskimo--drunkenness is frequent
wherever the protecting arm of government does not interfere.
What bearing does this have on the theory of racial poisons?
Surely a consideration of the principle of natural selection will make
it clear that alcohol is acting as an instrument of racial purification
through the elimination of weak stocks. It is a drastic sort of
purification, which one can hardly view with complacency; but the
effect, nevertheless, seems clear cut.
To demonstrate the action of natural selection, we must first
demonstrate the existence of variations on which it can act. This is
not difficult in the character under consideration--namely, the greater
or less capacity of individuals to be attracted by alcohol, to an
injurious degree.
As G. Archdall Reid has pointed out,[18] men drink for at least three
different reasons: (1) to satisfy thirst. This leads to the use of a
light wine or a malt liquor. (2) To gratify the palate. This again
usually results in the use of drinks of low alcohol content, in which
the flavor is the main consideration. (3) Finally, men drink "to induce
those peculiar feelings, those peculiar frames of mind" caused by
alcohol.
Although the three motives may and often do coexist in the same
individual, or may animate him at different periods of life, the fact
remains that they are quite distinct. Thirst and taste do not lead to
excessive drinking; and there is good evidence that the degree of
concentration and the dosage are important factors in the amount of harm
alcohol may do to the individual. The concern of evolutionists,
therefore, is with the man who is so constituted that the mental effects
of alcohol acting directly on the brain are pleasing, and we must show
that there is a congenital variability in this mental quality, among
individuals.
Surely an appeal to personal experience will leave little room for doubt
on that point. The alcohol question is so hedged about with moral and
ethical issues that those who never get drunk, or who perhaps never even
"take a drink," are likely to ascribe that line of conduct to superior
intelligence and great self-control. As a fact, a dispassionate analysis
of the case will show that why many such do not use alcoholic beverages
to excess is because intoxication has no charm for them. He is so
constituted that the action of alcohol on the brain is distasteful
rather than pleasing to him. In other cases it is variation in
controlling satisfaction of immediate pleasures for later greater good.
Some of the real inebriates have a strong will and a real desire to be
sober, but have a different mental make-up, vividly described by William
James:[19] "The craving for drink in real dipsomaniacs, or for opium and
chloral in those subjugated, is of a strength of which normal persons
can have no conception. 'Were a keg of rum in one corner of the room,
and were a cannon constantly discharging balls between me and it, I
could not refrain from passing before that cannon in order to get that
rum. If a bottle of brandy stood on one hand, and the pit of hell yawned
on the other, and I were convinced I should be pushed in as surely as I
took one glass, I could not refrain.' Such statements abound in
dipsomaniacs' mouths." Between this extreme, and the other of the man
who is sickened by a single glass of beer, there are all intermediates.
Now, given an abundant and accessible supply of alcohol to a race, what
happens? Those who are not tempted or have adequate control, do not
drink to excess; those who are so constituted as to crave the effects of
alcohol (once they have experienced them), and who lack the ability to
deny themselves the immediate pleasure for the sake of a future gain,
seek to renew these pleasures of intoxication at every opportunity; and
the well attested result is that they are likely to drink themselves to
a premature death.
Although it is a fact that the birth-rate in drunkard's families may be
and often is larger than that of the general population,[20] it is none
the less a fact that many of the worst drunkards leave no or few
offspring. They die of their own excesses at an early age; or their
conduct makes them unattractive as mates; or they give so little care to
their children that the latter die from neglect, exposure or accident.
As these drunkards would tend to hand down their own inborn peculiarity,
or weakness for alcohol, to their children, it must be obvious that
their death results in a smaller proportion of such persons in the next
generation. In other words, natural selection is at work again here,
with alcohol as its agent. By killing off the worst drunkards in each
generation, nature provides that the following generation shall contain
fewer people who lack the power to resist the attraction of the effect
of alcohol, or who have a tendency to use it to such an extent as to
injure their minds and bodies. And it must be obvious that the speed and
efficacy of this ruthless temperance reform movement are proportionate
to the abundance and accessibility of the supply of alcohol. Where the
supply is ample and available, there is certain to be a relatively high
death-rate among those who find it too attractive, and the average of
the race therefore is certain to become stronger in this respect with
each generation. Such a conclusion can be abundantly justified by an
appeal to the history of the Teutonic nations, the nations around the
Mediterranean, the Jews, or any race which has been submitted to the
test.
There seems hardly room for dispute on the reality of this phase of
natural selection. But there is another way in which the process of
strengthening the race against the attraction and effect of alcohol may
be going on at the same time. If the drug does actually injure the
germ-plasm, and set up a deterioriation, it is obvious that natural
selection is given another point at which to work. The more deteriorated
would be eliminated in each generation in competition with the less
deteriorated or normal; and the process of racial purification would
then go on the more rapidly. The fact that races long submitted to the
action of alcohol have become relatively resistant to it, therefore,
does not in itself answer the question of whether alcohol injures the
human germ-plasm.
The possible racial effect of alcoholization is, in short, a much more
complicated problem than it appears at first sight to be. It involves
the action of natural selection in several important ways, and this
action might easily mask the direct action of alcohol on the germ-plasm,
if there be any measurable direct result.
No longer content with a long perspective historical view, we will
scrutinize the direct investigations of the problem which have been made
during recent years. These investigations have in many cases been
widely advertised to the public, and their conclusions have been so much
repeated that they are often taken at their face value, without critical
examination.
It must be borne in mind that the solution of the problem depends on
finding evidence of degeneracy or impairment in the offspring of persons
who have used alcohol, and that this relation might be explainable in
one or more of three ways:
(1) It may be that alcoholism is merely a symptom of a degenerate stock.
In this case the children will be defective, not because their parents
drank, but because their parents were defective--the parents' drinking
being merely one of the symptoms of their defect.
(2) It may be that alcohol directly poisons the germ-plasm, in such a
way that parents of sound stock, who drink alcoholic beverages, will
have defective offspring.
(3) It may be that the degeneracy observed in the children of drunkards
(for of course no one will deny that children of drunkards are
frequently defective) is due solely to social and economic causes, or
other causes in the environment: that the drunken parents, for instance,
do not take adequate care of their children, and that this lack of care
leads to the defects of the children.
The latter influence is doubtless one that is nearly always at work, but
it is wholly outside the scope of the present inquiry, and we shall
therefore ignore it, save as it may appear incidentally. Nor does it
require emphasis here; for the disastrous social and economic effects of
alcoholism are patent to every observer. We find it most convenient to
concentrate our attention first on the second of the questions above
enumerated: to ask whether there is any good evidence that the use of
alcoholic beverages by men and women really does originate degeneracy in
their offspring.
To get such evidence, one must seek an instance that will be crucial,
one that will leave no room for other interpretations. One must,
therefore, exclude consideration of cases where a mother drank before
child birth. It is well-known that alcohol can pass through the
placenta, and that if a prospective mother drinks, the percentage of
alcohol in the circulation of the unborn child will very soon be nearly
equal to that in her own circulation. It is well established that such a
condition is extremely injurious to the child; but it has nothing
directly to do with heredity. Therefore we can not accept evidence of
the supposed effect of alcohol on the fertilized egg-cell, at any stage
in its development, because that is an effect on the individual, not on
posterity. And the only means by which we can wholly avoid this fallacy
is to give up altogether an attempt to prove our case by citing
instances in which the mother was alcoholic. If this is not done, there
will always be liability of mistaking an effect of prenatal nutrition
for a direct injury to the germ-plasm.
But if we can find cases where the mother was of perfectly sound stock,
and non-alcoholic; where the father was of sound stock, but alcoholic;
and where the offspring were impaired in ways that can be plausibly
attributed to an earlier injury to the germ-plasm by the father's
alcohol; then we have evidence that must weigh heavily with the
fair-minded.
An interesting case is the well-known one recorded by Schweighofer,
which is summarized as follows: "A normal woman married a normal man and
had three sound children. The husband died and the woman married a
drunkard and gave birth to three other children; one of these became a
drunkard; one had infantilism, while the third was a social degenerate
and a drunkard. The first two of these children contracted tuberculosis,
which had never before been in the family. The woman married a third
time and by this sober husband again produced sound children."
Although such evidence is at first sight pertinent, it lacks much of
being convincing. Much must be known about the ancestry of the drunken
husband, and of the woman herself, before it can be certain that the
defective children owe their defect to alcoholism rather than to
heredity.
We can not undertake to review all the literature of this subject, for
it fills volumes, but we shall refer to a few of the studies which are
commonly cited, by the believers in the racial-poison character of
alcohol, as being the most weighty.
Taav Laitinen of Helsingfors secured information from the parents of
2,125 babies, who agreed to weigh their infants once a month for the
first eight months after birth, and who also furnished information about
their own drinking habits. His conclusion is that the average weight of
the abstainer's child is greater at birth, that these children develop
more rapidly during the first eight months than do the children of the
moderate drinker, and that the latter exceed in the same way the
children of the heavier drinker. But a careful analysis of his work by
Karl Pearson, whose great ability in handling statistics has thrown
light on many dark places in the alcohol problem, shows[21] that
Professor Laitinen's statistical methods were so faulty that no weight
can be attached to his conclusions. Furthermore, he appears to have
mixed various social classes and races together without distinction; and
he has made no distinction between parents, one of whom drank, and
parents, both of whom drank. Yet, this distinction, as we have pointed
out, is a critical one for such inquiries. Professor Laitinen's paper,
according to one believer in racial poisons, "surpasses in magnitude and
precision all the many studies of this subject which have proved the
relation between drink and degeneracy." As a fact, it proves nothing of
the sort as to race degeneracy.
Again, T. A. MacNicholl reported on 55,000 American school children,
from 20,147 of whom he secured information about the parents' attitude
to alcoholic drinks. He found an extraordinarily large proportion (58%)
of deficient and backward children in the group. But the mere bulk of
his work, probably, has given it far more prestige than it deserves; for
his methods are careless, his classifications vague, his information
inadequate; he seems to have dealt with a degenerate section of the
population, which does not offer suitable material for testing the
question at issue; and he states that many of the children drank and
smoked,--hence, any defects found in them may be due to their own
intemperance, rather than that of their parents. In short, Dr.
MacNicholl's data offer no help in an attempt to decide whether
alcoholism is an inheritable effect.
Another supposed piece of evidence which has deceived a great many
students is the investigation of Bezzola into the distribution of the
birth-rate of imbeciles in Switzerland. He announced that in
wine-growing districts the number of idiots conceived at the time of the
vintage and carnival is very large, while at other periods it is almost
_nil_. The conclusion was that excesses of drunkenness occurring in
connection with the vintage and carnival caused this production of
imbeciles. But aside from the unjustified assumptions involved in his
reasoning, Professor Pearson has recently gone over the data and shown
the faulty statistical method; that, in fact, the number of imbeciles
conceived at vintage-time, in excess of the average monthly number, was
only three in spite of the large numbers! Bezzola's testimony, which has
long been cited as proof of the disastrous results of the use of alcohol
at the time of conception, must be discarded.
Demme's plausible investigation is also widely quoted to support the
belief that alcohol poisons the germ-plasm. He studied the offspring of
10 drunken and 10 sober pairs of parents, and found that of the 61
children of the latter, 50 were normal, while of the 57 progeny of the
drunkards, only nine were normal. This is a good specimen of much of the
evidence cited to prove that alcohol impairs the germ-plasm; it has been
widely circulated by propagandists in America during recent years. Of
course, its value depends wholly on whether the 20 pairs of parents were
of sound, comparable stock. Karl Pearson has pointed out that this is
not the case. Demme selected his children of drunkards by selecting
children who came to his hospital on account of imperfect development of
speech, mental defect, imbecility or idiocy. When he found families in
which such defective children occurred, he then inquired as to their
ancestry. Many of these children, he found, were reduced to a condition
approaching epilepsy, or actually epileptic, because they themselves
were alcoholic. Obviously such material can not legitimately be used to
prove that the use of alcohol by parents injures the heredity of their
children. The figures do not at all give the proof we are seeking, that
alcohol can so affect sound germ-plasm as to lead to the production of
defective children.
Dr. Bertholet made a microscopic examination of the reproductive glands
of 75 chronic male alcoholics, and in 37 cases he found them more or
less atrophied, and devoid of spermatozoa. Observing the same glands in
non-alcoholics who had died of various chronic diseases, such as
tuberculosis, he found no such condition. His conclusion is that the
reproductive glands are more sensitive to the effects of alcohol than
any other organ. So far as is known to us, his results have never been
discredited; they have, on the contrary, been confirmed by other
investigators. They are of great significance to eugenics, in showing
how the action of natural selection to purge the race of drunkards is
sometimes facilitated in a way we had not counted, through reduced
fertility due to alcohol, as well as through death due to alcohol. But
it should not be thought that his results are typical, and that all
chronic alcoholists become sterile: every reader will know of cases in
his own experience, where drunkards have large families; and the
experimental work with smaller animals also shows that long-continued
inebriety is compatible with great fecundity. It is probable that
extreme inebriety reduces fertility, but a lesser amount increases it in
the cases of many men by reducing the prudence which leads to limited
families.
In 1910 appeared the investigation of Miss Ethel M. Elderton and Karl
Pearson on school children in Edinburgh and Manchester.[22] Their aim
was to take a population under the same environmental conditions, and
with no discoverable initial differentiation, and inquire whether the
temperate and intemperate sections had children differing widely in
physique and mentality. Handling their material with the most refined
statistical methods, and in an elaborate way, they reached the
conclusion that parental alcoholism does not markedly affect the
physique or mentality of the offspring as children. Whether results
might differ in later life, their material did not show. Their
conclusions were as follows:
"(1) There is a higher death-rate among the offspring of alcoholic than
among the offspring of sober parents. This appears to be more marked in
the case of the mother than in the case of the father, and since it is
sensibly higher in the case of the mother who has drinking bouts
[periodical sprees] than of the mother who habitually drinks, it would
appear to be due very considerably to accidents and gross carelessness
and possibly in a minor degree to toxic effect on the offspring.
"Owing to the greater fertility of alcoholic parents, the net family of
the sober is hardly larger than the net family of the alcoholic. [It
should be remembered that the study did not include childless couples.]
"(2) The mean weight and height of the children of alcoholic parents are
slightly greater than those of sober parents, but as the age of the
former children is slightly greater, the correlations when corrected for
age are slightly positive, i.e., there is slightly greater height and
weight in the children of the sober."
"(3) The wages of the alcoholic as contrasted with the sober parent show
a slight difference compatible with the employers' dislike for an
alcoholic employee, but wholly inconsistent with a marked mental or
physical inferiority in the alcoholic parent.
"(4) The general health of the children of alcoholic parents appears on
the whole slightly better than that of sober parents. There are fewer
delicate children, and in a most marked way cases of tuberculosis and
epilepsy are less frequent than among the children of sober parents. The
source of this relation may be sought in two directions; the physically
strongest in the community have probably the greatest capacity and taste
for alcohol. Further the higher death rate of the children of alcoholic
parents probably leaves the fittest to survive. Epilepsy and
tuberculosis both depending upon inherited constitutional conditions,
they will be more common in the parents of affected offspring, and
probably if combined with alcohol, are incompatible with any length of
life or size of family. If these views be correct, we can only say that
parental alcoholism has no marked effect on filial health.
"(5) Parental alcoholism is not the source of mental defect in
offspring.
"(6) The relationship, if any, between parental alcoholism and filial
intelligence is so slight that even its sign can not be determined from
the present material.
"(7) The normal visioned and normal refractioned offspring appear to be
in rather a preponderance in the families of the drinking parents, the
parents who have 'bouts' give intermediate results, but there is no
substantial relationship between goodness of sight and parental
alcoholism. Some explanation was sought on the basis of alcoholic homes
driving the children out into the streets. This was found to be markedly
the case, the children of alcoholic parents spending much more of their
spare time in the streets. An examination, however, of the vision and
refraction of children with regard to the time they spent in-and
out-of-doors, showed no clear and definite result, the children who
spent the whole or most of their spare time in the streets having the
most myopia and also most normal sight. It was not possible to assert
that the outdoor life was better for the sight, or that the better sight
of the offspring of alcoholic parentage was due to the greater time
spent outdoors.
"(8) The frequency of diseases of the eye and eyelids, which might well
be attributed to parental neglect, was found to have little, if any,
relation to parental alcoholism.
"To sum up, then no _marked_ relation has been found between the
intelligence, physique or disease of the offspring and the parental
alcoholism in any of the categories mentioned. On the whole the balance
turns as often in favor of the alcoholic as of the non-alcoholic
parentage. It is needless to say that we do not attribute this to the
alcohol but to certain physical and possibly mental characters which
appear to be associated with the tendency to alcohol."
Of the many criticisms made of this work, most are irrelevant to our
present purpose, or have been satisfactorily met by the authors. It must
be said, however, that as the children examined were all school
children, the really degenerate offspring of alcoholics, if any such
existed, would not have been found, because they would not have been
admitted to the school. Further, it is not definitely known whether the
parents' alcoholism dated from before or after the birth of the child
examined. Then, the report did not exactly compare the offspring of
drinkers and non-drinkers, but classified the parents as those who
drank, and those who were sober; the latter were not, for the most part,
teetotalers, but merely persons whose use of alcohol was so moderate
that it exercised no visible bad influence on the health of the
individual or the welfare of the home. Something can be said on both
sides of all these objections; but giving them as much weight as one
thinks necessary, the fact remains that the Elderton-Pearson
investigation failed to demonstrate any racial poisoning due to alcohol,
in the kind of cases where one would certainly have expected it to be
demonstrated, if it existed.
Much more observation and measurement must be made before a
generalization can be safely drawn, as to whether alcohol is or is not a
racial poison, in the sense in which that expression is used by
eugenists. It has been shown that the evidence which is commonly
believed to prove beyond doubt that alcohol does injure the germ-plasm,
is mostly worthless. But it must not be thought that the authors intend
to deny that alcohol is a racial poison, where the dosage is very heavy
and continuous. If we have no good evidence that it is, we equally lack
evidence on the other side. We wish only to suggest caution against
making rash generalizations on the subject which lack supporting
evidence and therefore are a weak basis for propaganda.
So far as immediate action is concerned, eugenics must proceed on the
basis that there is no proof that alcohol as ordinarily consumed will
injure the human germ-plasm. To say this is not in any way to minify
the evil results which alcohol often has on the individual, or the
disastrous consequences to his offspring, euthenically. But nothing is
to be gained by making an assumption of "racial poisoning," and acting
on that assumption, without evidence that it is true; and the temperance
movement would command more respect from genetics if it ceased to allege
proof that alcohol has a directly injurious effect on the race, by
poisoning the human germ-plasm, when no adequate proof exists.
How, then, can one account for the immense bulk of cases, some of which
come within everyone's range of vision, where alcoholism in the parent
is associated with defect in the offspring? By a process of exclusion,
we are driven to the explanation already indicated: that alcoholism may
be a symptom, rather than a cause, of degeneracy. Some drunkards are
drunkards, because they come of a stock that is, in a way, mentally
defective; physical defects are frequently correlated in such stocks;
naturally the children inherit part or all of the parental defects
including, very likely, alcoholism; but the parent's alcoholism, we
repeat, must not be considered the _cause_ of the child's defect. The
child would have been defective in the same way, regardless of the
parent's beverage.
It follows, then, as a practical consequence for eugenics, that in the
light of present knowledge any campaign against alcoholic liquors would
be better based on the very adequate ground of physiology and economics,
than on genetics. From the narrowest point of view of genetics, the way
to solve the liquor problem would be, not to eliminate drink, but to
eliminate the drinker: to prevent the reproduction of the degenerate
stocks and the tainted strains that contribute most of the chronic
alcoholics. We do not mean to advocate this as the only proper basis for
the temperance campaign, because the physiological and economic aspects
are of sufficient importance to keep up the campaign at twice the
present intensity.[23] But it is desirable to have the eugenic aspect of
the matter clearly understood, and to point out that in checking the
production of defectives in the United States, eugenics will do its
share, and a big share, toward the solution of the drink problem, which
is at the same time being attacked along other and equally praiseworthy
lines by other people.
A number of other substances are sometimes credited with being racial
poisons.
The poison of _Spirochæte pallida_, the microörganism which causes
syphilis, has been widely credited with a directly noxious effect on the
germ-plasm, and the statement has been made that this effect can be
transmitted for several generations. On the other hand, healthy children
are reported as being born to cured syphilitics. Further evidence is
needed, taking care to eliminate cases of infection from the parents. If
the alleged deterioration really occurs, it will still remain to be
determined if the effect is permanent or an induction, that is, a change
in the germ-cells which does not permanently alter the nature of the
inherited traits, and which would disappear in a few generations under
favorable conditions.
The case against lead is similar. Sir Thomas Oliver, in his _Diseases of
Occupation_, sums up the evidence as follows:
"Rennert has attempted to express in statistical terms the varying
degrees of gravity in the prognosis of cases in which at the moment of
conception both parents are the subjects of lead poisoning, also when
one alone is affected. The malign influence of lead is reflected upon
the fetus and upon the continuation of the pregnancy 94 times out of 100
when both parents have been working in lead, 92 times when the mother
alone is affected, and 63 times when it is the father alone who has
worked in lead. Taking seven healthy women who were married to lead
workers, and in whom there was a total of 32 pregnancies, Lewin (Berlin)
tells us that the results were as follows: 11 miscarriages, one
stillbirth, 8 children died within the first year after their birth,
four in the second year, five in the third year and one subsequent to
this, leaving only two children out of 32 pregnancies as likely to live
to manhood. In cases where women have had a series of miscarriages so
long as their husbands worked in lead, a change of industrial
occupation on the part of the husband restores to the wives normal
child-bearing powers." The data of Constantin Paul, published as long
ago as 1860, indicated that lead exercised an injurious effect through
the male as well as the female parent. This sort of evidence is
certainly weak, in that it fails to take into account the possible
effects of environment; and one would do well to keep an open mind on
the subject. In a recent series of careful experiments at the University
of Wisconsin, Leon J. Cole has treated male rabbits with lead. He
reports: "The 'leaded' males have produced as many or more offspring
than normal fathers, but their young have averaged smaller in size and
are of lowered vitality, so that larger numbers of them die off at an
early age than is the case with those from untreated fathers."
[Illustration: EFFECT OF LEAD AS A "RACIAL POISON"
FIG. 7.--That lead poisoning can affect the germ plasm of
rabbits is indicated by experiments conducted by Leon J. Cole at the
University of Wisconsin. With reference to the above illustration,
Professor Cole writes: "Each of the photographs shows two young from the
same litter, in all cases the mother being a normal (nonpoisoned)
albino. In each of the litters the white young is from an albino father
which received the lead treatment, while the pigmented offspring is from
a normal, homozygous, pigmented male. While these are, it is true,
selected individuals, they represent what tend to be average, rather
than extreme, conditions. The albino male was considerably larger than
the pigmented male; nevertheless his young average distinctly smaller in
size. Note also the brighter expression of the pigmented young."]
There is, then, a suspicion that lead is a racial poison, but no
evidence as yet as to whether the effect is permanent or in the nature
of an induction.
This concludes the short list of substances for which there has been any
plausible case made out, as racial poisons. Gonorrhea, malaria, arsenic,
tobacco, and numerous other substances have been mentioned from time to
time, and even ardently contended by propagandists to be racial poisons,
but in the case of none of them, so far as we know, is there any
evidence to support the claim. And as has been shown, in the case of the
three chief so-called racial poisons, alcohol, syphilis and lead, the
evidence is not great. We are thus in a position to state that, from the
eugenists' point of view, the _origination_ of degeneracy, by some
direct action of the germ-plasm, is a contingency that hardly needs to
be reckoned with. Even in case the evidence were much stronger than it
is, the damage done may only be a physiological or chemical induction,
the effects of which will wear off in a few generations; rather than a
radical change in the hereditary constituents of the germ-plasm. The
germ-plasm is so carefully isolated and guarded that it is almost
impossible to injure it, except by treatment so severe as to kill it
altogether; and the degeneracy with which eugenists are called on to
deal is a degeneracy which is running along from generation to
generation and which, when once stopped by the cessation of
reproduction, is in little danger of being originated anew through some
racial poison.
Through these facts, the problem of race betterment is not only
immensely simplified, but it is clearly shown to be more a matter for
treatment by the biologist, acting through eugenics, than for the
optimistic improver of the environment.
There is another way in which it is widely believed that some such
result as a direct influence of the germ-plasm can be produced: that is
through the imaginary process known as maternal impression, prenatal
influence, etc. Belief in maternal impressions is no novelty. In the
book of Genesis[24] Jacob is described as making use of it to get the
better of his tricky father-in-law. Some animal breeders still profess
faith in it as a part of their methods of breeding: if they want a black
calf, for instance, they will keep a white cow in a black stall, and
express perfect confidence that her offspring will resemble midnight
darkness. It is easy to see that this method, if it "works," would be a
potent instrument for eugenics. And it is being recommended for that
reason. Says a recent writer, who professes on the cover of her book to
give a "complete and intelligent summary of all the principles of
eugenics":
"Too much emphasis can not be placed upon the necessity of young people
making the proper choice of mates in marriage; yet if the production of
superior children were dependent upon that one factor, the outlook would
be most discouraging to prospective fathers and mothers, for weak traits
of character are to be found in all. But when young people learn that by
a conscious endeavor to train themselves, they are thereby training
their unborn children, they can feel that there is some hope and joy in
parentage; that it is something to which they can look forward with
delight and even rapture; then they will be inspired to work hard to
attain the best and highest that there is in them, leading the lives
that will not only be a blessing to themselves, but to their succeeding
generation."
The author of this quotation has no difficulty in finding supporters.
Many physicians and surgeons, who are supposed to be trained in
scientific methods of thought, will indorse what she says. The author of
one of the most recent and in many respects admirable books on the care
of babies, is almost contemptuous in her disdain for those who think
otherwise:
"Science wrangles over the rival importance of heredity and environment,
but we women know what effects prenatal influence works on children."
"The woman who frets brings forth a nervous child. The woman who rebels
generally bears a morbid child." "Self-control, cheerfulness and love
for the little life breathing in unison with your own will practically
insure you a child of normal physique and nerves."
Such statements, backed up by a great array of writers and speakers whom
the layman supposes to be scientific, and who think themselves
scientific, can not fail to influence strongly an immense number of
fathers and mothers. If they are truly scientific statements, their
general acceptance must be a great good.
But think of the misplaced effort if these widespread statements are
false!
Is there, or is there not, a short cut to race betterment? Everyone
interested in the welfare of the race must feel the necessity of getting
at the truth in the case; and the truth can be found only by rigorously
scientific thought.
Let us turn to the observed facts. This sample is taken from the health
department of a popular magazine, quite recently issued:
"Since birth my body has been covered with scales strikingly resembling
the surface of a fish. My parents and I have expended considerable money
on remedies and specialists without deriving any permanent benefit. I
bathe my entire body with hot water daily, using the best quality of
soap. The scales fall off continually. My brother, who is younger than
myself, is afflicted with the same trouble, but in a lesser degree. My
sister, the third member of the family, has been troubled only on the
knees and abdomen. My mother has always been quite nervous and
susceptible to any unusual mental impression. She believes that she
marked me by craving fish, and preferring to clean them herself. During
the prenatal life of my brother, she worried much lest she might mark
him in the same way. In the case of my sister she tried to control her
mind."[25]
Another is taken from a little publication which is devoted to
eugenics.[26] As a "horrible example" the editor gives the case of Jesse
Pomeroy, a murderer whom older readers will remember. His father, it
appears, worked in a meat market. Before the birth of Jesse, his mother
went daily to the shop to carry a luncheon to her husband, and her eyes
naturally fell upon the bloody carcases hung about the walls.
Inevitably, the sight of such things would produce bloody thoughts in
the mind of the unborn child!
These are extreme cases; we quote from a medieval medical writer another
case that carries the principle to its logical conclusion: A woman saw a
Negro,--at that time a rarity in Europe. She immediately had a sickening
suspicion that her child would be born with a black skin. To obviate the
danger, she had a happy inspiration--she hastened home and washed her
body all over with warm water. When the child appeared, his skin was
found to be normally white--except between the fingers and toes, where
it was black. His mother had failed to wash herself thoroughly in those
places!
Of course, few of the cases now credited are as gross as this, but the
principle involved remains the same.
We will take a hypothetical case of a common sort for the sake of
clearness: the mother receives a wound on the arm; when her child is
born it is found to have a scar of some sort at about the same place on
the corresponding arm. Few mothers would fail to see the result of a
maternal impression here. But how could this mark have been transmitted?
This is not a question of the transmission of acquired characters
through the germ-plasm, or anything of that sort, for the child was
already formed when the mother was injured. One is obliged, therefore,
to believe that the injury was in some way transmitted through the
placenta, the only connection between the mother and the unborn child;
and that it was then reproduced in some way in the child.
Here is a situation which, examined in the cold light of reason, puts a
heavy enough strain on the credulity. Such an influence can reach the
embryo only through the blood of the mother. Is it conceivable to any
rational human being, that a scar, or what not, on the mother's body can
be dissolved in her blood, pass through the placenta into the child's
circulation, and then gather itself together into a definite scar on the
infant's arm?
There is just as much reason to expect the child to grow to resemble the
cow on whose milk it is fed after birth, as to expect it to grow to
resemble its mother, because of prenatal influence, as the term is
customarily used, for once development has begun, the child draws
nothing more than nourishment from its mother.
Of course we are accustomed to the pious rejoinder that man must not
expect to understand all the mysteries of life; and to hear vague talk
about the wonder of wireless telegraphy. But wireless telegraphy is
something very definite and tangible--there is little mystery about it.
Waves of a given frequency are sent off, and caught by an instrument
attuned to the same frequency. How any rational person can support a
belief in maternal impressions by such an analogy, if he knows anything
about anatomy and physiology, passes comprehension.
Now we are far from declaring that a reason can be found for everything
that happens. Science does not refuse belief in an observed fact merely
because it is unexplainable. But let us examine this case of maternal
impressions a little further. What can be learned of the time element?
Immediately arises the significant fact that most of the marks,
deformities and other effects which are credited to prenatal influence
must on this hypothesis take place at a comparatively late period in the
antenatal life of the child. The mother is frightened by a dog; the
child is born with a dog-face. If it be asked when her fright occurred,
it is usually found that it was not earlier than the third month, more
likely somewhere near the sixth.
But it ought to be well known that the development of all the main parts
of the body has been completed at the end of the second month. At that
time, the mother rarely does more than suspect the coming of the child,
and events which she believes to "mark" the child, usually occur after
the fourth or fifth month, when the child is substantially formed, and
it is impossible that many of the effects supposed to occur could
actually occur. Indeed, it is now believed that most errors of
development, such as lead to the production of great physical defects,
are due to some cause within the embryo itself, and that most of them
take place in the first three or four weeks, when the mother is by no
means likely to influence the course of embryological development by her
mental attitude toward it, for the very good reason that she knows
nothing about it.
Unless she is immured or isolated from the world, nearly every expectant
mother sees many sights of the kind that, according to popular
tradition, cause "marks." Why is it that results are so few? Why is it
that women doctors and nurses, who are constantly exposed to unpleasant
sights, have children that do not differ from those of other mothers?
Darwin, who knew how to think scientifically, saw that this is the
logical line of proof or disproof. When Sir Joseph Hooker, the botanist
and geologist who was his closest friend, wrote of a supposed case of
maternal impression, one of his kinswomen having insisted that a mole
which appeared on her child was the effect of fright upon herself for
having, before the birth of the child, blotted with sepia a copy of
Turner's _Liber Studiorum_ that had been lent her with special
injunctions to be careful, Darwin[27] replied: "I should be very much
obliged, if at any future or leisure time you could tell me on what you
ground your doubtful belief in imagination of a mother affecting her
offspring. I have attended to the several statements scattered about,
but do not believe in more than accidental coincidences. W. Hunter told
my father, then in a lying-in hospital, that in many thousand cases he
had asked the mother, before her confinement, whether anything had
affected her imagination, and recorded the answers; and absolutely not
one case came right, though, when the child was anything remarkable,
they afterwards made the cap to fit."
Any doctor who has handled many maternity cases can call to mind
instances where every condition was present to perfection, for the
production of maternal impression, on the time-honored lines. None
occurred. Most mothers can, if they give the matter careful
consideration, duplicate this experience from their own. Why is it that
results are so rare?
That Darwin gave the true explanation of a great many of the alleged
cases is perfectly clear to us. When the child is born with any peculiar
characteristic, the mother hunts for some experience in the preceding
months that might explain it. If she succeeds in finding any experience
of her own at all resembling in its effects the effect which the infant
shows, she considers she has proved causation, has established a good
case of prenatal influence.
It is not causation; it is coincidence.
If the prospective mother plays or sings a great deal, with the idea of
giving her child a musical endowment, and the child actually turns out
to have musical talent, the mother at once recalls her yearning that
such might be the case; her assiduous practice which she hoped would be
of benefit to her child. She immediately decides that it did benefit
him, and she becomes a convinced witness to the belief in prenatal
culture. Has she not herself demonstrated it?
She has not. But if she would examine the child's heredity, she would
probably find a taste for music running in the germ-plasm. Her study and
practice had not the slightest effect on this hereditary disposition; it
is equally certain that the child would have been born with a taste for
music if its mother had devoted eight hours a day for nine months to
cultivating thoughts of hatred for the musical profession and repugnance
for everything that possesses rhythm or harmony.
It necessarily follows, then, that attempts to influence the inherent
nature of the child, physically or mentally, through "prenatal culture,"
are doomed to disappointment. The child develops along the lines of the
potentialities which existed in the two germ-cells that united to become
its origin. The course of its development can not be changed in any
specific way by any corresponding act or attitude of its mother, good
hygiene alone need be her concern.
It must necessarily follow that attempts to improve the race on a large
scale, by the general adoption of prenatal culture as an instrument of
eugenics, are useless.
Indeed, the logical implication of the teaching is the reverse of
eugenic. It would give a woman reason to think she might marry a man
whose heredity was most objectionable, and yet, by prenatal culture,
save her children from paying the inevitable penalty of this weak
heritage. The world has long shuddered over the future of the girl who
marries a man to reform him; but think what it means to the future of
the race if a superior girl, armed with correspondence school lessons in
prenatal culture, marries a man to reform his children!
Those who practice this doctrine are doomed to disillusion. The time
they spend on prenatal culture is not cultivating the child; it is
merely perpetuating a fallacy. Not only is their time thus spent
wasted, but worse, for they might have employed it in ways that really
would have benefited the child--in open-air exercise, for instance.
To recapitulate, the facts are:
(1) That there is, before birth, no connection between mother and child,
by which impressions on the mother's mind or body could be transmitted
to the child's mind or body.
(2) That in most cases the marks or defects whose origin is attributed
to maternal impression, must necessarily have been complete long before
the incident occurred which the mother, after the child's birth,
ascribes as the cause.
(3) That these phenomena usually do not occur when they are, and by
hypothesis ought to be, expected. The explanations are found after the
event, and that is regarded as causation which is really coincidence.
Pre-natal care as a euthenic measure is of course not only legitimate
but urgent. The embryo derives its entire nourishment from the mother;
and its development depends wholly on its supply of nourishment.
Anything which affects the supply of nourishment will affect the embryo
in a general, not a particular way. If the mother's mental and physical
condition be good, the supply of nourishment to the embryo is likely to
be good, and development will be normal. If, on the other hand, the
mother is constantly harassed by fear or hatred, her physical health
will suffer, she will be unable properly to nourish her developing
offspring, and it may be its poor physical condition when born,
indicates this.
Further, if the mother experiences a great mental or physical shock, it
may so upset her health that her child is not properly nourished, its
development is arrested, mentally as well as physically, and it is born
defective. H. H. Goddard, for example, tells[28] of a high-grade
imbecile in the Training School at Vineland, N. J. "Nancy belongs to a
thoroughly normal, respectable family. There is nothing to account for
the condition unless one accepts the mother's theory. While it sounds
somewhat like the discarded theory of maternal impression, yet it is not
impossible that the fright and shock which the mother received may have
interfered with the nutrition of the unborn child and resulted in the
mental defect. The story in brief is as follows. Shortly before this
child was born, the mother was compelled to take care of a sister-in-law
who was in a similar condition and very ill with convulsions. Our
child's mother was many times frightened severely as her sister-in-law
was quite out of her mind."
It is easily understandable that any event which makes such an
impression on the mother as to affect her health, might so disturb the
normal functioning of her body that her child would be badly nourished,
or even poisoned. Such facts undoubtedly form the basis on which the
airy fabric of prenatal culture was reared by those who lived before the
days of scientific biology.
Thus, it is easy enough to see the real explanation of such cases as
those mentioned near the beginning of this discussion. The mothers who
fret and rebel over their maternity, she found, are likely to bear
neurotic children. It is obvious (1) that mothers who fret and rebel are
quite likely themselves to be neurotic in constitution, and the child
naturally gets its heredity from them: (2) that constant fretting and
rebellion would so affect the mother's health that her child would not
be properly nourished.
When, however, she goes on to draw the inference that "self-control,
cheerfulness and love ... will practically insure you a child normal in
physique and nerves," we are obliged to stop. We know that what she says
is not true. If the child's heredity is bad, neither self-control,
cheerfulness, love, nor anything else known to science, can make that
heredity good.
At first thought, one may wish it were otherwise. There is something
inspiring in the idea of a mother overcoming the effect of heredity by
the sheer force of her own will-power. But perhaps in the long run it is
as well; for there are advantages on the other side. It should be a
satisfaction to mothers to know that their children will not be marked
or injured by untoward events in the antenatal days; that if the
child's heredity can not be changed for the better, neither can it be
changed for the worse.
The prenatal culturists and maternal-impressionists are trying to place
on her a responsibility which she need not bear. Obviously, it is the
mother who is most nearly concerned with the bogy of maternal
impressions, and it should make for her peace of mind to know that it is
nothing more than a bogy. It is important for the expectant mother to
keep herself in as nearly perfect condition as possible, both physically
and mentally. Her bodily mechanism will then run smoothly, and the child
will get from her blood the nourishment needed for its development.
Beyond that there is nothing the mother can do to influence the
development of her child.
There is another and somewhat similar fallacy which deserves a passing
word, although it is of more concern to the livestock breeder than to
the eugenist. It is called telegony and is, briefly, this: that
conception by a female results in a definite modification of her
germ-plasm from the influence of the male, and that this modification
will be shown in the offspring she may subsequently bear to a second
male. The only case where it is often invoked in the human race is in
miscegenation. A white woman has been married to a Negro, for instance,
and has borne one or more mulatto offspring. Subsequently, she mates
with a white man; but her children by him, instead of being pure white,
it is alleged, will be also mulattoes. The idea of telegony, the
persistent influence of the first mating, may be invoked to explain this
discrepancy.
It is a pure myth. There is no good evidence[29] to support it, and
there is abundant evidence to contradict it. Telegony is still believed
by many animal breeders, but it has no place in science. In such a case
as the one quoted, the explanation is undoubtedly that the supposed
father is not the real one; and this explanation will dispose of all
other cases of telegony which can not be explained, as in most instances
they can be, by the mixed ancestry of the offspring and the innate
tendency of all living things to vary.
Now to sum up this long chapter. We started with a consideration of the
germ-plasm, the physical basis of life; pointing out that it is
continuous from generation to generation, and potentially immortal; that
it is carefully isolated and guarded in the body, so that it is not
likely to be injured by any ordinary means.
One of the logical results of this continuity of the germ-plasm is that
modifications of the body of the parent, or acquired characters, can
hardly be transferred to the germ-plasm and become a part of the
inheritance. Further the experimental evidence upholds this position,
and the inheritance of acquired body characters may be disregarded by
eugenics, which is therefore obliged to concern itself solely with the
material already in existence in the germ-plasm, except as that material
may be changed by variation which can neither be predicted nor
controlled.
The evidence that the germ-plasm can be permanently modified does not
warrant the belief; and such results, if they exist at all, are not
large enough or uniform enough to concern the eugenist.
Pre-natal culture and telegony were found to be mere delusions. There is
no justification for hoping to influence the race for good through the
action of any kind of external influences; and there is not much danger
of influencing it for ill through these external influences. The
situation must be faced squarely then: if the race is to be improved, it
must be by the use of the material already in existence; by endeavor to
change the birth-and death-rates so as to alter the relative proportions
of the amounts of good and bad germ-plasm in the race. This is the only
road by which the goal of eugenics can be reached.