David McClelland

David Clarence McClelland (1917-1998) was an American psychologist known for his work on human motivation. He developed Achievement Motivation Theory, often called need theory or n-achievement theory, which holds that individual behavior at work is driven mainly by needs for achievement, power and affiliation. McClelland also created new scoring systems for the Thematic Apperception Test used to measure these needs. He taught at Wesleyan University, at Harvard University from 1956 to 1987, and at Boston University afterward, and a 2002 survey in the Review of General Psychology ranked him as the fifteenth most cited psychologist of the twentieth century.