Henry Goddard (1866-1957) was a prominent psychologist and eugenicist in the early 20th century who focused primarily on inheritability intelligence. Highly influenced by Mendelian genetics, Goddard believed that “feeble-mindedness” could be attributed to a single recessive gene.
Goddard was best known for his book, The Kallikak Family: A Study in the Heredity of Feeble-Mindedness. It presents his allegedly true study of the “Kallikak” family (a pseudonym he created himself). The patriarch of the family, Martin Kallikak Sr., was a young soldier who created two lines of progeny: one from an illegitimate liaison with a “feeble-minded” tavern girl, and a second from a marriage to an upstanding Quaker woman. Goddard believed that he found a marked difference between the two branches of the Kallikak family. According to Goddard, the descendants of Kallikak’s union with the tavern girl were more often affected by “mental defects,” while the offspring from his union with the Quaker woman were “normal” citizens. Goddard attributed this difference to the different genetic makeup of the two women.
Though Goddard reversed many of his opinions later in life, the Kallikak study was crucial to the momentum and popular dissemination of eugenics in the United States (the book was a best seller).