Solomon Eliot Asch (September 14, 1907 – February 20, 1996) was a Polish gestalt psychologist and pioneer in social psychology in the United States. He created seminal pieces of work in impression formation, prestige suggestion, conformity, and many other topics in social psychology. His work follows a common theme of Gestalt psychology that the whole is not only greater than the sum of its parts, but the nature of the whole fundamentally alters the parts.