Aaron Rosanoff

Aaron Joshua Rosanoff (26 June 1878 in Pinsk, Russia—7 January 1943) was a Russian-American psychiatrist who studied psychosis and was closely associated with Eugenics Record Office and a member of the Eugenics Research Association.

Born in Russia, Rosanoff emigrated to the United States in 1891 and received an MD from Cornell in 1900. He worked as a physician at Kings Park Hospital from 1901 until 1922. From 1922 until his death in 1943, Rosanoff was a psychiatrist for the L.A. Diagnostic Clinic, and was California's State Director of Institutions and State Commissioner of Lunacy in 1933.

Closely associated with Eugenics Record Office and a member of the Eugenics Research Association, Rosanoff was a member of the American Eugenics Society Advisory council from 1923 to 1935. He was also a member of the editorial Board of the American Journal of Psychiatry and author of the Manual of Psychiatry (1920), a medical school textbook.

Rosanoff studied both the physiological and genetic factors that lead to various psychosis, and is best known for his Theory of Personality, which broke down the human personality into seven scales: Normal, Hysteroid, Manic, Depressive, Autistic, Paranoid, and Epileptoid. These scales first modelled in the Humm-Wadsworth Temperament Scale personality test in 1935.