Early in the twentieth century, the eugenics movement became popular throughout the world. This led to the forced sterilization and prohibition of marriage for the developmentally disabled in most of the developed world and was later used by Hitler as rationale for the mass murder of mentally challenged individuals during the Holocaust. The eugenics movement was later thought to be seriously flawed and in violation of human rights and the practice of forced sterilization and prohibition from marriage was discontinued by most of the developed world by the mid 20th century.