During the period 1840–1940 biology and medicine were transformed, and took on major implications for social amelioration and population growth. New biological disciplines such as genetics and psychology consciously used scientific explanation to redefine the life of the individual. This volume originates from a Past and Present conference on ‘The Roots of Sociobiology’ held in 1978 and incorporates the results of recent research on problems in the social relations of the biological sciences. The authors describe different historical aspects of the interrelationship of technical experience and social policy in the fields of health, education and social welfare. Insight is provided into contemporary debates on physical and racial deterioration, the sources and distribution of intelligence, the application of evolutionary biology to social and political theory, and the analysis of human societies. The authors raise issues of topical interest, such as the emergence and influence of eugenics, the origin and impact of intelligence testing, the relationship between eugenics, genetics and evolutionary theory, and the causes of the twentieth-century reduction in infant and maternal mortality. The area of coverage is Britain, America and Germany. The introduction provides a review of recent research on the social relations of biology and medicine.