In the history given susceptibility to this disease behaves as a
Mendelian dominant. We cannot as yet say whether this is or is not a
general rule. In describing the heredity of diseases primarily due to
infection, one or two important cautions must be observed. Of course
the source of the infection cannot be "hereditary," and apparently it
is only in comparatively few instances that infection occurs during
fetal life. To some infections certain persons are susceptible, others
are not; some when susceptible are capable of developing immunity,
others are not. When an infection is of such character and prevalence
that practically all persons in approximately similar environments of
a given character are infected, susceptibility or the power of
developing immunity will determine whether or not an individual will
exhibit the disease caused by the infective agent. Practically all
persons living in the denser communities are infected with
tuberculosis; those who are susceptible and incapable of developing
immunity succumb, the insusceptible and those developing immunity do
not. These conditions are heritable; but in speaking of the heredity
of such a disease as tuberculosis it should be clear that the heredity
concerned is really that of susceptibility and the power of developing
immunity. Yet the person who is really susceptible can, by taking
sufficient precaution, escape serious infection, and thus the result
for that person would be the same as if he were insusceptible, but his
offspring would have to take similar precautions if they were to
escape the disease.
[Illustration: FIG. 22. Family history showing
feeble-mindedness. Data from Goddard. _A_, alcoholic; _d.i._,
died in infancy; _E_, epileptic; _ill._, illegitimate; _in._,
incest; *, same individual as _III_, 6; _n.m._, not married;
_S_, sexual pervert; _T_, tuberculous.]
[Illustration: FIG. 23.--Family history showing
angio-neurotic oedema. (From "Treasury of Human
Inheritance.")]
[Illustration: FIG. 24.--Family history showing tuberculosis.
(Data from Klebs, after Whetham in "Treasury of Human
Inheritance.")]
We cannot speak of heredity in connection with diseases to which all
are susceptible and incapable of developing immunity. The presence or
absence of such a disease is determined solely by the presence or
absence of infection. Many physical and mental defects result from
infection as the primary cause. If the infection is one to which all
exposed are susceptible and incapable of developing immunity we cannot
speak of the defect as in any way hereditary; if the infection is one
to which some are susceptible, others not, to which some can develop
immunity, others cannot, then we may speak of the defect as
hereditary. Thus certain forms of blindness or insanity are due
primarily to gonorrheal or syphilitic infection, insusceptibility to
which is rare or unknown. Such defects cannot be considered as
affording evidence of heredity though they reappear in successive
generations.
In general the subject of the heredity of immunity and susceptibility
forms one of the most important eugenic aspects of this whole subject.
In a few cases it is known that immunity or insusceptibility to
specific forms of infection is a unit character which follows
Mendelian laws in heredity. It can be added to races or subtracted
from them and pure bred immune races built up. So far this has not
been demonstrated for man. There is some circumstantial evidence that
immunity to specific forms of infection has been a great, although
hitherto neglected, factor in man's evolution, and even in the history
of his civilization and conquest. It is at once obvious that here is a
great field for the common labor of the students of heredity and of
medicine and of Eugenics.
Fig. 25 illustrates a family history of infertility. This is
apparently hereditary, but before that could be asserted definitely to
be so here or in any similar case, we should know that the infertility
were not the result of an infection to which immunity is rare or
unknown. That infertility is really hereditary in this instance is
indicated, first, by the fact that the person marked A later, by a
second marriage into fertile stock, had a large family, and second, by
the fact that the individual B and his child by marriage into fertile
stocks produced in the last generation again a large family and so
saved this whole family from extinction.
[Illustration: FIG. 25.--Family history showing infertility.
(From Whetham.)]
Before leaving the subject of the heredity of the kinds of traits we
have been using as illustrations, we should add just a word. It is
often objected that one cannot properly speak of the heredity of such
general things as "insanity" or "deaf-mutism" or "blindness" or "heart
disease," because each of these includes a great variety of specific
forms of these disorders which cannot strictly, medically, be
compared. But the student of heredity replies that when he speaks of
the heredity of insanity or heart disease, that is often just what
he means. He means that often no particular form of these defects is
necessarily strictly heritable as such, but that in a family there may
be a general instability of nervous system or circulatory system,
which may take any one of several possible specific forms, the form
actually appearing depending upon particular conditions which are
frequently environmental and beyond determination. In some cases
specific forms of disorder are actually heritable as such.
Such an inclusive thing as "ability" may depend upon many different
specific conditions. Yet there are families in which persons of
exceptional ability are unusually frequent. The fact that persons of
ability are more frequent in certain families than in the general
population of the same social class and with about the same
opportunity for the demonstration of inherent ability, gives evidence
of its heredity, although we may not be able to summarize the facts
under any particular law but must adhere to their statistical
expression.
[Illustration: FIG. 26.--Family history showing ability.
(From Whetham.)]
Figs. 26 and 27 illustrate two such pedigrees of ability. In each of
these histories there is also a line of "unsoundness" the descent of
which it is interesting to trace. It is instructive to compare here
the progeny of matings of different kinds. In generation IV of Fig.
26, the 9th and 10th persons are brother and sister. The sister was of
considerable ability and married into a family of ability, producing 8
offspring, 5 of whom were able. The brother was a "normal" person and
married a similar individual, producing 10 "normal" children. It would
be interesting to know the details regarding these two large families
of cousins. Another interesting comparison is found in this pedigree.
The four able brothers in generation III, coming from a stock of
demonstrated ability, married women of undemonstrated ability and all
told had 13 children (IV) of whom only 3 showed ability and all of
these were in a single family. In this family of the fourth brother
two of the able members married into able families, and among their 11
children (second and fifth families in generation V) 8 showed ability;
the third able member of this family, however, married as her uncles
had, a person not known as able, and none of their 6 children showed
unusual ability (sixth family in generation V). Fig. 27 affords other
illustrations of this same kind. Thus in generation III the 5th and
7th persons are able cousins of able parentage. The former married a
normal and 1 of their 5 children showed ability; the latter married a
person of ability and 5 of their 8 children showed ability. In both
pedigrees the "careers" of those in the last generation are partly
incomplete.
[Illustration: FIG. 27.--Family history showing ability.
Paternal ancestry of family shown in Fig. 26. (From
Whetham.)]
In discussing pedigrees of ability it should be borne in mind that the
larger proportion of able males as compared with females is hardly
significant for the study of heredity; it may merely reflect the
unfortunate fact that women have not had the same opportunity to
demonstrate inherent ability as have men; or it may evidence the still
more unfortunate fact that the distinguished achievements of able
women have not been socially recognized as such and recorded as they
have been for the other sex.
Fig. 28 gives an interesting, though abbreviated, pedigree of three
very able and well-known families. In this history only persons whose
ability is in science are marked as able. Charles Darwin is the third
individual in the third generation. His cousin, Francis Galton, the
founder of Eugenics, is the next to the last person in the same
generation.
Many similar cases of the unusual frequency of individuals of musical
or religious ability in certain families have been published by Galton
and are well known. "As long as ability marries ability, a large
proportion of able offspring is a certainty, and ability is a more
valuable heirloom in a family than mere material wealth, which,
moreover, will follow ability sooner or later."
We might contrast with such families as have been recorded in the
three preceding figures some well-known families at the other pole of
society. As an interesting example we have the family described by
Poellmann. This was established by two daughters of a woman drunkard
who in five or six generations produced all told 834 descendants. The
histories of 709 of these are known. Of the 709, 107 were of
illegitimate birth; 64 were inmates of almshouses; 162 were
professional beggars; 164 were prostitutes and 17 procurers; 76 had
served sentences in prison aggregating 116 years; 7 were condemned for
murder. This family is still a fertile one and the cost to the State,
i. e., the taxpayers, already a million and a quarter dollars, is
still increasing.
[Illustration: FIG. 28.--History (condensed and incomplete)
of three markedly able families. (From Whetham.)]
One of the best known families of this type is the so-called "Jukes"
family of New York State so carefully investigated by Dugdale. This
family is traced from the five daughters of a lazy and irresponsible
fisherman born in 1720. In five generations this family numbered about
1,200 persons, including nearly 200 who married into it. The histories
of 540 of these are well known and about 500 more are partly known.
This family history was easier to follow than are some others because
there was very little marriage with the foreign-born--"a distinctively
American family." Of these 1,200 idle, ignorant, lewd, vicious,
pauper, diseased, imbecile, insane, and criminal specimens of
humanity, about 300 died in infancy. Of the remaining 900, 310 were
professional paupers in almshouses a total of 2,300 years (at whose
expense?); 440 were physically wrecked by their own diseased
wickedness; more than half of the women were prostitutes; 130 were
convicted criminals; 60 were habitual thieves; 7 were murderers. Not
one had even a common school education. Only 20 learned a trade, and
10 of these learned it in State prison! They have cost the State over
a million and a quarter dollars, and the cost is still going on. Who
pays this bill? What right had an intelligent and humane society to
allow these poor unfortunates to be born into the kind of lives they
had to lead, not by choice but by the disadvantage of birth? Darwin
wrote long ago "... except in the case of man himself, hardly anyone
is so ignorant as to allow his worst animals to breed."
[Illustration: FIG. 29.--History of _Die Familie Zero_.
(Condensed from Joerger's data, partly after Davenport.)]
Probably the most complete family history of this kind ever worked out
is that of the "Familie Zero"--a Swiss family whose pedigree has been
recently unraveled in a splendid manner by Joerger. In the seventeenth
century this family divided into three lines; two of these have ever
since remained valued and highly respected families, while the third
has descended to the depths. This third line was established by a
man who was himself the result of two generations of intermarriage,
the second tainted with insanity. He was of roving disposition, and in
the Valla Fontana found an Italian vagrant wife of vicious character.
Their son inherited fully his parental traits and himself married a
member of a German vagabond family--Marcus, known to this day as a
vagabond family. This marriage sealed the fate of their hundreds of
descendants. This pair had seven children, all characterized by
vagabondage, thievery, drunkenness, mental and physical defect, and
immorality. Their history for the three succeeding generations is
incompletely summarized in Fig. 29. In 1905, 190 members of this
family were known to be living, and probably many living are unknown
on account of illegitimate birth.
In 1861 a sympathetic and charitable priest attempted to save from
their obvious fate many of these "Zero" children and others who
resided in and near his village, by placing them in industrious and
respectable families to be reared under more favorable auspices. The
attempt failed utterly, for every one of the "Zero" children either
ran away or was enticed away by his relatives.
The blame for such an atrocity as this family or the Jukes does not
rest with these persons themselves; it must be placed squarely upon
the shoulders and consciences of the intelligent members of society
who have permitted these predetermined degenerates to be brought into
the world, and who are to-day taking no broadly sympathetic view of
their treatment by exercising preventive measures. _Laissez faire?_
At the risk of easing the conscience, let us finally return to the
other side of society and look at a summarized statement of the
Edwards Family given by Boies and drawn from Winship's account of the
descendants of Jonathan Edwards. "1,394 of his descendants were
identified in 1900, of whom 295 were college graduates; 13 presidents
of our greatest colleges; 65 professors in colleges, besides many
principals of other important educational institutions; 60 physicians,
many of whom were eminent; 100 and more clergymen, missionaries, or
theological professors; 75 were officers in the army and navy; 60
prominent authors and writers, by whom 135 books of merit were
written and published and 18 important periodicals edited; 33 American
States and several foreign countries, and 92 American cities and many
foreign cities, have profited by the beneficent influence of their
eminent activity; 100 and more were lawyers, of whom one was our most
eminent professor of law; 30 were judges; 80 held public office, of
whom one was Vice President of the United States; 3 were United States
Senators; several were governors, members of Congress, framers of
State constitutions, mayors of cities, and ministers to foreign
courts; one was president of the Pacific Mail Steamship Company; 15
railroads, many banks, insurance companies, and large industrial
enterprises have been indebted to their management. Almost if not
every department of social progress and of the public weal has felt
the impulse of this healthy and long-lived family. It is not known
that any one of them was ever convicted of crime."
The serious consideration of bodies of facts like those contained in
some of these pedigrees leads every thoughtful and sympathetic, every
humanely minded, human being to ask--What _can_ we _do_ about it? The
display of such conditions stimulates us to measures of relief. It is
greatly to be regretted that the honest desire to do good often leads
to the performance of ill-considered or unconsidered acts which may
result in positive injury to the constitution of society, or at any
rate at best merely in the amelioration of the immediate situation
without reference to ultimate profit or penalty, or to the necessity
for interminable amelioration. Such relief leaves out of account the
fact that modifications are not heritable--not permanent, practically
without effect in the long run. "Good intentions" have a certain
well-known value as paving material, but not as building material.
The science of Eugenics includes not only the study of the data in
this field, but further the formulation of definite courses of
procedure; but it insists that these be based upon scientific
principles and not upon emotional states. Philanthropic relief has
become a serious business--is becoming a science. Eugenics is a
science and it aims to put the human race upon such a level that the
need for philanthropic relief will be less and continually less. We
shall then be able to devote more of the resources of our time and
money and energy to the production of permanent results. The Eugenist
pleads in this work for more sympathetic consideration of the problems
of relief--for a sympathy which is wider, which transcends the
individual person and reaches the social group, even the nation or
race. For just as a society is something more than the sum of its
individual parts when taken separately, so the consideration of all
the component individuals of a society taken separately and by
themselves, results in something less than social consideration. Again
"Charity refers to the individual; Statesmanship to the nation;
Eugenics cares for both."
* * * * *
What, then, does the Eugenist propose to do? What is the eugenic
program? Eugenics is not an academic matter--not an armchair science.
It is intensely practical--so very practical, indeed, that the
Eugenist hesitates to make many suggestions of a definite nature
looking directly and immediately toward specific action. Something
must precede action. The Eugenist has been ridiculed as one
responsible for the absurd schemes proposed in his name, perhaps
seriously, by the unscientific but well-intentioned sympathizer. Many
persons have been led to object to what they believed to be a eugenic
program which is not a eugenic program at all. Thus the willingness of
some to offer adverse criticism of the subject and its aims has grown
largely out of a common misconception of the matter and has led Galton
to say, "As in most other cases of novel views, the wrongheadedness of
objectors to Eugenics has been curious." As a scientist the Eugenist
realizes clearly and fully that his new science is in a very early
stage of its development. It is just entering upon what are the first
stages in the history of any science, namely, the periods of the
formulation of elementary ideas and the collection of facts. There are
certain groups of facts, however, of glaring significance and
undoubted meaning, and upon these as a basis the Eugenist already has
a few, a very few, concrete suggestions for eugenic practice. In
conclusion, then, we may outline tentatively and briefly a
conservative eugenic program somewhat as follows:
First of all there must be an extensive collection of exact data--of
the facts regarding all the varied aspects of racial history and
evolution. These facts must be collected with great care and under the
strictest scientific conditions. In this matter particularly must we
"desert verbal discussion for statistical facts." Figures can't lie,
but liars can figure. What we need first of all is the accumulation of
masses of cold, hard facts, uncolored by any point of view, untinged
by any propaganda: facts regarding the net fertility of all classes;
facts regarding the racial effects of all sorts of environmental and
occupational conditions; facts regarding variability and variation in
the race; facts regarding human heredity of normal and pathological
conditions, of physical and psychical traits. We have merely scratched
the surface of the great masses of such data to be had for the
looking. As Davenport has recently put it in his valuable essay on
"Eugenics"--
"While the acquisition of new data is desirable, much can be done by
studying the extant records of institutions. The amount of such data
is enormous. They lie hidden in records of our numerous charity
organizations, our 42 institutions for the feeble-minded, our 115
schools and homes for the deaf and blind, our 350 hospitals for the
insane, our 1,200 refuge homes, our 1,300 prisons, our 1,500 hospitals
and our 2,500 almshouses. Our great insurance companies and our
college gymnasiums have tens of thousands of records of the characters
of human blood lines. These records should be studied, their
hereditary data sifted out and ... placed in their proper relations"
that we may learn of "the great strains of human protoplasm that are
coursing through the country." Thus shall we learn "not only the
method of heredity of human characteristics but we shall identify
those lines which supply our families of great men: ... We shall also
learn whence come our 300,000 insane and feeble-minded, our 160,000
blind or deaf, the 2,000,000 that are annually cared for by our
hospitals and Homes, our 80,000 prisoners and the thousands of
criminals that are not in prison, and our 100,000 paupers in
almshouses and out.
"This three or four per cent of our population is a fearful drag on
our civilization. Shall we as an intelligent people, proud of our
control of nature in other respects, do nothing but vote more taxes or
be satisfied with the great gifts and bequests that philanthropists
have made for the support of the delinquent, defective, and dependent
classes? Shall we not rather take the steps that scientific study
dictates as necessary to dry up the springs that feed the torrent of
defective and degenerate protoplasm?
"Greater tasks than those contemplated in the broadest scheme of the
Eugenics committee have been carried out in this country. If only one
half of one per cent of the 30 million dollars annually spent on
hospitals, 20 millions on insane asylums, 20 millions for almshouses,
13 millions on prisons, and 5 millions on the feeble-minded, deaf and
blind were spent on the study of the bad germ plasm that makes
necessary the annual expenditure of nearly 100 millions in the care of
its produce we might hope to learn just how it is being reproduced and
the best way to diminish its further spread. A _new_ plague that
rendered four per cent of our population, chiefly at the most
productive age, not only incompetent, but a burden costing 100
million dollars yearly to support, would instantly attract universal
attention, and millions would be forthcoming for its study as they
have been for the study of cancer. But we have become so used to
crime, disease and degeneracy that we take them as necessary evils.
That they were, in the world's ignorance, is granted. That they must
remain so, is denied."
Of course one should not jump from this to the conclusion that the
fact of heredity is responsible for all of this defect. Disease is so
often the result of infections to which none is immune, and defect is
frequently the result of such disease. Warbasse has recently stated
that "At least one fourth of our public institutions for caring for
defectives is made necessary by venereal disease." Doubtless an
appreciable share of this fourth is the result of hereditary
tendencies, the expression of which gives the opportunity for such
infection. Here as elsewhere no single factor accounts for all of the
facts, although when, as the result of the increase of knowledge, we
shall become able to make more definite statements, we no doubt shall
find that heredity is the most important single factor in the
disgraceful prevalence of crime, disease, and defect in our
communities: indeed this is practically demonstrated to-day. These are
questions of the most fundamental importance in our national
life-history: our only "hope of perpetuity" lies in the right solution
of such problems. And the crying need is for facts, always more facts.
The Galton Laboratory for Eugenics is already doing much in this
direction and is publishing in the "Treasury of Human Inheritance"
scores of human pedigrees. An agency is already in operation in this
country. The American Breeders Association has appointed a Committee
and Sub-Committees under highly competent leaders for the collection
of exact data of human heredity upon a large scale. There is
opportunity for everyone to help in this work in connection with the
Eugenics Record Office already referred to.