Nazi eugenics influenced by eugenics in the United States
Nazi eugenics refers to the social policies of eugenics in Nazi Germany, composed of various ideas about genetics which are now considered pseudoscientific. The racial ideology of Nazism placed the biological improvement of the German people by selective breeding of "Nordic" or "Aryan" traits at its center. These policies were used to justify the involuntary sterilization and mass-murder of those deemed "undesirable".
Eugenics research in Germany before and during the Nazi period was similar to that in the United States (particularly California), by which it had been heavily inspired. However, its prominence rose sharply under Adolf Hitler's leadership when wealthy Nazi supporters started heavily investing in it. The programs were subsequently shaped to complement Nazi racial policies.Those targeted for murder under Nazi eugenics policies were largely people living in private and state-operated institutions, identified as "life unworthy of life" (Lebensunwertes Leben). They included prisoners, degenerates, dissidents, and people with congenital cognitive and physical disabilities (Erbkranken) – people who were considered to be feeble-minded. In fact being diagnosed with "feeblemindedness" (German: Schwachsinn) was the main label approved in forced sterilization, which included people who were diagnosed by a doctor as, or otherwise seemed to be:Relationship with the U.S. eugenics movement
The early German eugenics movement was led by Wilhelm Schallmayer and Alfred Ploetz. Henry Friedlander wrote that although the German and American eugenics movements were similar, the German movement was more centralized and did not contain as many diverse ideas as the American movement.  Unlike the American movement, one publication and one society, the German Society for Racial Hygiene, represented all eugenicists.Edwin Black wrote that after the eugenics movement was well established in the United States, it was spread to Germany. California eugenicists began producing literature promoting eugenics and sterilization and sending it overseas to German scientists and medical professionals.  By 1933, California had subjected more people to forceful sterilization than all other U.S. states combined. The forced sterilization program engineered by the Nazis was partly inspired by California's.In 1927, the Kaiser Wilhelm Institute for Anthropology (KWIA), an organization which concentrated on physical and social anthropology as well as human genetics, was founded in Berlin with significant financial support from the American philanthropic group, the Rockefeller Foundation. German professor of medicine, anthropology and eugenics Eugen Fischer was the director of this organization, a man whose work helped provide the scientific basis for the Nazis' eugenics policies. The Rockefeller Foundation even funded some of the research conducted by Josef Mengele before he went to Auschwitz.Upon returning from Germany in 1934, where more than 5,000 people per month were being forcibly sterilized, the California eugenics leader C. M. Goethe bragged to a colleague:Nazi eugenics program
In organizing their eugenics program the Nazis were inspired by the United States' programs of forced sterilization, especially on the eugenics laws that had been enacted in California.The Law for the Prevention of Hereditarily Diseased Offspring, enacted on July 14, 1933, allowed the compulsory sterilisation of any citizen who according to the opinion of a "Genetic Health Court" "suffered" from a list of alleged genetic disorders and required physicians to register every case of hereditary illness known to them, except in women over 45 years of age. Physicians could be fined for failing to comply.
In 1934, the first year of the Law's operation, nearly 4,000 people appealed against the decisions of sterilization authorities. A total of 3,559 of the appeals failed. By the end of the Nazi regime, over 200 Hereditary Health Courts (Erbgesundheitsgerichte) were created, and under their rulings over 400,000 persons were sterilized against their will.