Need theory, also known as Three Needs Theory,[1] proposed by psychologist David McClelland, is a motivational model that attempts to explain how the needs for achievement, power, and affiliation affect the actions of people from a managerial context. This model was developed in the 1960s[2]; two decades after Maslow's hierarchy of needs was first proposed in the early 1940s. McClelland stated that we all have these three types of motivation regardless of age, sex, race, or culture.