born Sept. 9, 1890, Mogilno, Ger.
died Feb. 12, 1947, Newtonville, Mass., U.S.
German-U.S. social psychologist.
After training and teaching in Berlin, he immigrated to the U.S., where he taught at the University of Iowa (1935–45) and later became director of a group dynamics research centre at the Massachusetts Institute of Technology (1945–47). He is best known for his field theory of behaviour, which holds that human behaviour is a function of an individual's psychological environment. To fully understand and predict human behaviour, according to Lewin, one must view the totality of events in a person's psychological field, or "lifespace." His works include A Dynamic Theory of Personality (1935) and Field Theory in Social Science (1951).