People often define themselves as members' of multiple social groups -- race, nationality, gender, religion, etc.  My primary stream of research investigates this phenomenon and demonstrates that people's psychological experience of managing multiple identities has consequences for groups and organizations. For instance, I have shown that intrapersonal identity conflict harms interpersonal problem-solving, while intrapersonal identity compatibility leads to cooperative behavior. In current projects, I am investigating contextual factors that influence people's experience of multiple identities and the effects of managing multiple identities and crossing group boundaries on prosocial behavior, gender relations, and conflict resolution in organizations.