In 1912, Henry Herbert Goddard published The Kallikak Family: A Study in the Heredity of Feeble-Mindedness, hereafter The Kallikak Family, in which he argues that people inherit feeble-mindedness, which is presently known as intellectual disability. Feeble-mindedness, according to Goddard, is the source of, what he refers to as, degeneracy, including behaviors such as alcoholism, criminal behavior, prostitution, and sexual promiscuity. At the time Goddard wrote his book, many researchers questioned whether people inherited what they considered bad traits, such as feeble-mindedness, criminality, and immorality, and what people could do to get rid of such bad traits. Those ideas reflected the emerging eugenics movement of the early twentieth century. In The Kallikak Family, Goddard explores ideas central to eugenics, including how people can increase good traits and reduce bad traits in the population, For decades, supporters of eugenics cited The Kallikak Family as proof that people inherit such traits, but more recent investigations have discredited Goddard's research as bad science, poorly conceived and biased.
Contributors