Eugenics is the study and practice of selective breeding applied to humans, with the aim of improving the species. In a historical and broader sense, eugenics can also be a study of “improving human genetic qualities.” Advocates of eugenics sought to counter what they regarded as dysgenic dynamics within the human gene pool. Specifically, in regard to the continuation of congenital disorders and factors impacting overall societal intelligence relating to the heritability of IQ.
Eugenics was widely popular in the early decades of the 20th century, but has largely fallen into disrepute after having become associated with Nazi Germany. Since the postwar period, both the public and the scientific communities have associated eugenics with Nazi abuses, such as enforced racial hygiene, human experimentation, and the extermination of “undesired” population groups. However, developments in genetic, genomic, and reproductive technologies at the end of the 20th century have raised many new questions and concerns about the meaning of eugenics and its ethical and moral status in the modern era.