In this article we suggest that events and contexts relevant to the initiation and regulation of intentional behavior can function either to support autonomy (i.e., to promote choice) or to control behavior (i.e., to pressure one toward specific outcomes). Research herein reviewed indicates that this distinction is relevant to specific external events and to general interpersonal contexts as well as to specific internal events and to general personality orientations. That is, the distinction is relevant whether one's analysis focuses on social psychological variables or on personality variables. The research review details those contextual and person factors that tend to promote autonomy and those that tend to control. Furthermore, it shows that autonomy support has generally been associated with more intrinsic motivation, greater interest, less pressure and tension, more creativity, more cognitive flexibility, better conceptual learning, a more positive emotional tone, higher self-esteem, more trust, greater persistence of behavior change, and better physical and psychological health than has control. Also, these results have converged across different assessment procedures, different research methods, and different subject populations. On the basis of these results, we present an organismic perspective in which we argue that the regulation of intentional behavior varies along a continuum from autonomous (i.e., self-determined) to controlled. The relation of this organismic perspective to historical developments in empirical psychology is discussed, with a particular emphasis on its implications for the study of social psychology and personality.