Descriptive norms, or cognitions concerning the dominant beliefs, values, and behaviors of a particular reference group, are distinct from personal values and predict a wide range of cultural behavior. However, questions remain as to when and in what contexts descriptive norms predict behavior and what cultural, situational, and individual difference factors influence their motivational force. In this article, we focus on three primary motive goals that may help us determine when descriptive norms are particularly predictive: the goal to manage uncertainty and threat, the goal to manage impressions, and goals derived from power and dependence. We argue that descriptive norms serve important epistemic, identity, and social coordinative functions that help satisfy these goals.