[Sidenote: Meaning of eugenics.]
Eugenics, or the science of human good breeding, is just now the most
popular of the problems concerning human sex and reproduction. In
recent years, the biological investigators of heredity have published
some startling facts which show that the human race must soon check its
reckless propagation of the unfit and encourage reproduction by the
best types of men and women. This is not the place for a review of the
eugenic propositions. Those interested will find them in non-technical
form in many books (see the bibliographical chapter of this book, page
248).
[Sidenote: Eugenics in biology.]
Some of the chief facts of eugenics should be a part of every
well-organized scheme of sex-instruction, and taught through biology
(Sec. 17). Probably no other topic in biology is so likely to make an
ethical-social appeal, for the central point of eugenics is the
responsibility of the individual whose uncontrolled sexual actions may
transmit undesirable and heritable qualities and bring a train of
disaster to generations of descendants.
[Sidenote: Relation of eugenics and sex-hygiene.]
At this point we digress to correct the widespread error in confusing
sex-hygiene and eugenics. Many people who ought to know better use the
two terms synonymously, perhaps because they are afraid of that
comparatively novel but frank prefix in "sex-hygiene." The fact is that
eugenics and sex-hygiene have little in common. Eugenics is the
science of reproducing better humans by applying the established laws
of genetics or heredity. In brief, it means, on the positive side,
selecting desirable people as parents; and, negatively, preventing
propagation by the undesirables. This is the sum total of the task of
eugenics in the accurate sense of the term.
[Sidenote: Facts of heredity.]
So far as we know, each coming generation will inherit only qualities
that the parents inherited from their parents. It is a well-known
principle of biology that changes in the bodies of human beings during
their lifetime (dating from the fertilized egg that produces the
individual) are never in any noticeable degree inherited by
descendants. In short, acquired characteristics of the body tissues do
not influence the germ plasm, the living matter concerned with heredity
and reproduction, but the germ plasm that determines what the next
generation will inherit is fixed at birth. Thus tuberculosis,
alcoholism, gonorrhea, and syphilis may be acquired during the life of
an individual, but do not become fixed in the germ plasm. If the
infants show effects of any of these diseases, it is not because of
true heredity but because they were infected or influenced before
birth. Rarely does this happen to children of a tuberculous mother, but
often to those of a syphilitic mother. In a gonorrheal ophthalmia
neonatorum (specific inflammation of infants' eyes) it is a case of
infection _during_ birth.
[Sidenote: Sex-hygiene and eugenics parallel.]
Thus, it appears that sex-hygiene either personal or social (concerned
with venereal diseases) is not a part of eugenics. It is, however, a
phase of euthenics, which deals with the environmental factors that
affect the individual life. It is clear, then, that sex-hygiene (in the
strict medical sense) and eugenics are parallel and not conflicting.
Eugenics aims to select better parents who will transmit their own
qualities genetically. Sex-hygiene in its personal and social aspects
will make healthier parents able to give their offspring a healthier
start in life, especially because the offspring is free from the
prenatal effects of disease.
The teaching of heredity and eugenics is intended to develop a sense of
individual responsibility for the transmission of one's good or bad
inherited qualities to offspring. The teaching of sex-hygiene, either
personal or social, looks towards improving personal health and
preventing infection and injurious influence on the unborn next
generation. Obviously, we need both sex-hygiene and eugenics as part of
the larger sex-instruction.