Social identity theory holds that identities are social in nature—that is, their power is derived from the degree to which people consider membership with a group as important to their own ...

Three decades after its first appearance, identity process theory remains a vibrant and useful integrative framework in which identity, social action and social change can be collectively examined.

influence identity, fuel intragroup collaboration, and power intergroup conflict. Social psychology, evolutionary theory, and cognitive neuroscience have insights into in-group and out-group dynamics.