of the entire Institute as well as remaining head of his department. Rüdin was among the first to write about the "dangers" of hereditary defectives and the supposed value of the Nordic race as "culture creators". By 1920, his colleague Alfred Hoche published, with lawyer Karl Binding, the influential "Allowing the Destruction of Life Unworthy of Living". In 1930, Rüdin was a leading German representative at the First International Congress for Mental Hygiene, held in Washington, US, arguing for eugenics. In 1932, he became President of the International Federation of Eugenics Organizations. He was in contact with Carlos Blacker of the British Eugenics Society, and sent him a copy of pre-Nazi voluntary sterilization laws enacted in Prussia; a precursor to the Nazi forced sterilization laws that Rüdin is said to have already prepared in his desk drawer. From 1935 to 1945, he was President of the Society of German Neurologists and Psychiatrists (GDNP), later renamed the German Association for Psychiatry, Psychotherapy and Neurology (DGPPN). The American Rockefeller Foundation funded numerous international researchers to visit and work at Rüdin's psychiatric genetics department, even as late as 1939. These included Eliot Slater and Erik Stromgren, considered the founding fathers of psychiatric genetics in Britain and Scandinavia respectively, as well as Franz Josef Kallmann, who became a leading figure in twins research in the US after emigrating in 1936. Kallmann had claimed in 1935 that 'minor anomalies' in otherwise unaffected relatives of schizophrenic people should be grounds for compulsory sterilization. Rüdin's research was also supported with manpower and financing from the German National Socialists. Nazi expert In 1933, Ernst Rüdin, Alfred Ploetz, and several other experts on racial hygiene were brought together to form the Expert Committee on Questions of Population and Racial Policy under Reich Interior Minister Wilhelm Frick. The committee's ideas were used as a scientific basis to justify the racial policy of Nazi Germany and its "Law for the Prevention of Hereditarily Diseased Offspring" was passed by the German government on 1 January 1934. Rüdin was such an avid proponent that colleagues nicknamed him the "Reichsfuhrer for Sterilization" In a speech to the German Society for Rassenhygiene published in 1934, Rüdin recalled the early days of trying to alert the public to the special value of the Nordic race and the dangers of defectives. He stated: "The significance of Rassenhygiene racial hygiene did not become evident to all aware Germans