David McClelland

David McClelland, 1917- 1998 (born Mt. Vernon[?], New York) was a psychologist. He proposed a theory of motivation based on personality and learned needs. His theory of manifest needs claimed that human motivation was a result of three manifest needs. The manifest needs were for achievement, power and affiliation. The importance of each need varies from individual and cultural background. For example, some individuals value achievement more than affiliation.