An extension of the Maslow's theory - Clayton Alderfer formulated a need category model. Existence needs are concerned with survival. The Relatedness needs stress the importance of interpersonal, social relationships. The Growth needs are concerned with the individual's intrinsic desire for personal development. There hasn't been a great deal of research on this theory.
Most contemporary theories tend to support.
Once aroused, nAch makes salient the psychological rewards associated with challenge and accomplishment. Since these rewards are contingent upon meeting internal standards of excellence, performance should increase The strength of nAch will be positively correlated with performance in these settings.