FROM WIKIPEDIA:
Upon moving to become Professor of Clinical Psychiatry at the University of Munich in 1903, Kraepelin increasingly wrote on social policy issues. He was a strong and influential proponent of eugenics and racial hygiene. His publications included a focus on alcoholism, crime, degeneration and hysteria.[12] Kraepelin was convinced that such institutions as the education system and the welfare state, because of their trend to break the processes of natural selection, undermined the Germans’ biological "struggle for survival".[5] He was concerned to preserve and enhance the German people, the Volk, in the sense of nation or race. He appears to have held Lamarckian concepts of evolution, such that cultural deterioration could be inherited. He was a strong ally and promoter of the work of fellow psychiatrist (and pupil and later successor as director of the clinic) Ernst Rudin to clarify the mechanisms of genetic inheritance as to make a so-called "empirical genetic prognosis".[12]
Martin Brune has pointed out that Kraepelin and Rudin also appear to have been ardent advocates of a self-domestication theory, a version of social Darwinism which held that modern culture was not allowing people to be weeded out, resulting in more mental disorder and deterioration of the gene pool. Kraepelin saw a number of "symptoms" of this, such as "weakening of viability and resistance, decreasing fertility, proletarianisation, and moral damage due to "penning up people" [Zusammenpferchung]. He also wrote that "the number of idiots, epileptics, psychopaths, criminals, prostitutes, and tramps who descend from alcoholic and syphilitic parents, and who transfer their inferiority to their offspring, is incalculable". He felt that "the well-known example of the Jews, with their strong disposition towards nervous and mental disorders, teaches us that their extraordinarily advanced domestication may eventually imprint clear marks on the race". Brune states that Kraepelin's nosological system was "to a great deal, built on the degeneration paradigm".[13]