Since the late 19th century, doctors and scientists had been developing theories of racial purity based on eugenics, a concept popular at the time that developed from several disciplines including social history, biology, anthropology and genetics. As Weindling (1989) explained, there had been several movements in Germany since the end of World War I concerned with the 'degeneration' of German racial purity that culminated with the founding in 1927 of the Kaiser Wilhelm Institute for Anthropology, Human Heredity and Eugenics.[3] Although there had been demands since the early 1920s for legislation on sterilisation and euthanasia, these were rejected because it was believed that positive eugenics was more representative of the Weimar political structures and the nation's social needs.