ABSTRACT The present study distinguished reactive and reflective conceptions of autonomy. Following Henry Murray, personality theorists such as Gough and Heilbrun (1983) have emphasized the interpersonal and reactive aspects of autonomy, defining it as an orientation to act independently of others. More recently, Deci and Ryan (1991) highlighted the intrapersonal and reflective aspects of autonomy, describing it in terms of experiencing a sense of choicefulness about one's actions. Study 1 showed that measures derived from the two conceptions of autonomy are loosely related and that only reactive autonomy is associated with the Big Five trait factors of personality. Study 2 used an interval-contingent experience sampling methodology to show that reactive and reflective autonomy relate in different ways to daily affect and to the use of mood regulation strategies. Study 3 used an event-contingent experience sampling methodology to show that the social experiences associated with the two types of autonomy varied as a function of whether the interactions involved peers or authority figures. Together, the studies demonstrate the importance of distinguishing reactive and reflective conceptions of autonomy.