Who am I? What am I about? What is my place in my social group? What is important to me? What do I value? What do I want to do with my life? These are all questions related to what psychologists call identity. Many theorists have argued that we are driven to answer these questions, particularly during adolescence. In this article, I summarize an expectancy value perspective on identity and identity formation. Within this framework, identity can be conceptualized in terms of two basic sets of self perceptions: (a) perceptions related to skills, characteristics, and competencies, and (b) perceptions related to personal values and goals. Together these two sets of self perceptions inform both individuals' expectations for success and the importance they attach to becoming involved in a wide range of tasks. Within this perspective, then, I focus on the role personal and collective identities can play on motivated action through their influence on expectations for success and subjective task values. I also discuss briefly how personality and collective identities develop over time. (Contains 1 figure.)