Eugenics is a term coined to the study and practice of breeding better plants and animals useful to ma, and likewise safeguarding and improving the human heritage. Positive eugenic aims to increase reproduction of individuals who have traits, such as high intelligence and physical strength or fitness, which are considered to be valuable to society. Negative eugenics seeks to decrease reproduction among people believed to be inferior or below average mentally and physically.
The social direction of human evolution is not a new idea. In ancient Sparta infanticide was practised to rid their society of abnormal or defective individuals and to prevent their increase. Plato’s proposed that neither defective children nor those produced by defective parents ought to be reared. He also held that chronic individuals and victims of self-indulgence should be denied medical aid, and the morally degenerate executed. All this to improve the race and create superior offspring, by the unions of the best men and women.
These examples are enough to show the nature of the main questions that arise in attempting the social direction of human evolution: towards what goals should eugenics be directed? To achieve these goals we must understand the mechanism of heredity and the relative power of heredity and environment in moulding a person’s traits.
Heredity is determined by genes, which can either be recessive or dominant. The significance of this for eugenics can be unmistakeable: a considerable proportion of the genes in any person, and therefore in the entire population, are hidden, and to that extent the measure of eugenics must be applied blindly.
The age-old battle of nature versus nurture must also be considered. Studies of monozygotic twins raised separately revealed that their physical traits and mentality are similar. But it is undeniable that past experience and present environment can suppress, diminish or enhance the expression of such characteristics. The...