David Clarence McClelland (May 20, 1917 – March 27, 1998) was an
American psychologist, noted for his work on motivation
Need Theory. He published a number of works during the 1950s and the 1990s and developed new scoring systems for the
Thematic Apperception Test (TAT) and its descendants. McClelland is credited with developing the Achievement Motivation Theory commonly referred to as need achievement or
n-achievement theory. A
Review of General Psychology survey, published in 2002, ranked McClelland as the 15th most cited psychologist of the 20th century.