When the Kaiser Wilhelm Institute for Anthropology, Human Heredity and Eugenics opened its doors in 1927, it could rely on wide political approval. In 1933 the institute and its founding director Eugen Fischer came under pressure to adjust, which they were able to ward off through Selbstgleichschaltung (auto-coordination). The Third Reich brought about a mutual beneficial servicing of science and politics. With their research into hereditary health and racial policies the institute’s employees provided the Brownshirt rulers with legitimating grounds. This volume traces the history of the Kaiser Wilhelm Institute for Anthropology, Human Heredity and Eugenics between democracy and dictatorship. Attention is turned to the haunting transformation of the research program, the institute’s integration into the national and international science panorama, and its relationship to the ruling power. The volume also confronts the institute’s interconnection to the political crimes of Nazi Germany terminating in bestial medical crimes.