Social identity theory is a social psychological theory addressing self‐categorizations and group behaviors deriving from social group memberships, location in social structure, group status mobility, and intergroup relations. Because social groups create both self identities and social roles, role identities formed as part of a collectivity may intertwine with social identities. Among individuals, social identities have been conceptualized as sources of self‐esteem and may relate to pain tolerance and stereotype threat. In some initial formulations, out‐group stereotypes and prejudice have been linked through social comparison processes and group cohesion to the desire to maintain or elevate the social identities and self‐worth associated with group affiliation. Other derivations of the theory include self‐categorization theory, social creativity, and in‐group favoritism.