Biological determinism, also known as genetic determinism, is the belief that human behaviour is directly controlled by an individual's genes or some component of their physiology, generally at the expense of the role of the environment, whether in embryonic development or in learning. Genetic reductionism is a similar concept, but it is distinct from genetic determinism in that the former refers to the level of understanding, while the latter refers to the supposedly causal role of genes. Biological determinism has been associated with movements in science and society including eugenics, scientific racism, and the debates around the heritability of IQ, the basis of sexual orientation, and sociobiology.
The early eugenicist Francis Galton invented the term eugenics and popularized the phrase nature and nurture.
E. O. Wilson reignited debate on biological determinism with his 1975 book Sociobiology: The New Synthesis.
Eugenics is a set of beliefs and practices that aim to improve the genetic quality of a human population. Historically, eugenicists have attempted to alter human gene pools by excluding people and groups judged to be inferior or promoting those judged to be superior. In recent years, the term has seen a revival in bioethical discussions on the usage of new technologies such as CRISPR and genetic screening, with heated debate around whether these technologies should be considered eugenics or not.
A 1930s exhibit by the Eugenics Society. Two of the signs read "Healthy and Unhealthy Families" and "Heredity as the Basis of Efficiency".
Francis Galton, an early eugenicist, coined the term itself.[need quotation to verify]
G. K. Chesterton, an opponent of eugenics, photographed by Ernest Herbert Mills in 1909
Schloss Hartheim, a former center for Nazi Germany's Aktion T4 campaign