Eugenics is the study of attempting to improve the human race by selective breeding. Its rationale is to remove bad or deleterious genes from the population, increasing the genetic fitness of humanity as a result. Campaigns to stop the criminal, the poor, the handicapped, and the mentally ill from passing on their genes were supported in the past by such notable people as British feminist Marie Stopes and Irish playwright George Bernard Shaw. In the United States in the early 1900s, enforced sterilization was sometimes carried out on those deemed unfit to reproduce.

One ethical problem with practical eugenics is empowering a governmental or individual body to decide what a desirable characteristic is, and what is not. Nazi Germany had a eugenics program in place prior to and during World War II. Initially, targeted citizens were inmates of mental institutions, but quickly the reasons for sterilization became increasingly...