The Social Direction of Evolution: An Outline of the Science of Eugenics

The text outlines the aims and methods of eugenics as a biological and social science, arguing for deliberate measures to influence human heredity. After surveying historical context and recent developments, it explains variability, heredity, and Mendelian principles, discusses regression and probability, and presents statistical charts and family pedigrees tracing congenital and mental conditions. Case histories and illustrative diagrams accompany analysis of traits, disease, and ability. The final sections translate biological findings into a program of social measures and policies intended to encourage the reproduction of desirable traits and restrict transmission of deleterious ones, while urging cautious, scientifically grounded application.