- 1887 – Wolfgang Köhler, German psychologist and phenomenologist (d. 1967).
- 1947 – Joseph Nicolosi, American clinical psychologist (d. 2017).
Wolfgang Köhler (21 January 1887 to 11 June 1967) was a German psychologist and phenomenologist who, like Max Wertheimer and Kurt Koffka, contributed to the creation of Gestalt psychology.
During the Nazi regime in Germany, he protested against the dismissal of Jewish professors from universities, as well as the requirement that professors give a Nazi salute at the beginning of their classes. In 1935 he left the country for the United States, where Swarthmore College in Pennsylvania offered him a professorship. He taught with its faculty for 20 years, and did continuing research. A Review of General Psychology survey, published in 2002, ranked Köhler as the 50th most cited psychologist of the 20th century.
Joseph Nicolosi (24 January 1947 to 08 March 2017) was an American clinical psychologist who advocated and practised “reparative therapy”, a form of the pseudoscientific treatment of conversion therapy that he claimed could help people overcome or mitigate their homosexual desires and replace them with heterosexual ones. Nicolosi was a founder and president of the National Association for Research and Therapy of Homosexuality (NARTH). Medical institutions warn that conversion therapy is ineffective and may be harmful, and that there is no evidence that sexual orientation can be changed by such treatments.
Nicolosi described his ideas in Reparative Therapy of Male Homosexuality: A New Clinical Approach (1991) and three other books. Nicolosi proposed that homosexuality is often the product of a condition he described as gender-identity deficit caused by an alienation from, and perceived rejection by, formative individuals of the subject’s gender which interrupts normal masculine or feminine identification process. He also held that adaptation to gender trauma during formative years could alienate a child from their “fundamental nature.” His goal was to restore “that which functions in accordance with its biological design.”