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.
by the hypothesis that the alcohol eliminated the weaker germs in the
parents, and allowed only the stronger germs to be used for
reproduction.
Applied Eugenics by Roswell H. Johnson and Paul Popenoe
(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, Fere 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 _Spirochaete pallida_, the microorganism 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.