Self-categorization theory (SCT) is a major theory in social psychology that has had, and is having, a significant impact in areas such as political behavior and political psychology (e.g., political values, partisan identity, leadership, collective action, discrimination, social cohesion, intergroup political conflict and co-operation, negotiation). SCT is a development of social identity theory (SIT) and both theories concern group and intergroup behavior. These theories are part of an intergroup relations tradition (deriving from the work of Solomon Asch, Muzafer Sherif, and Kurt Lewin) in social psychology and related disciplines where the focus is not just on the individual as an individual but also the individual as a group member within a complex social structure the impacts on their psychology (referred to as interactionism).

In SIT, it ...