IDENTITY THEORY AND SOCIAL IDENTITY THEORY Identity theory had its beginnings in structural symbolic interactionism (Stryker 1980) and social identity theory began with work on social categorization

Identity theory and social identity theory have more points of overlap than differences in their understanding of the self. For this reason, we argue that the unification of these two theories is advisable in order to both avoid redundancies in theorizing about the self and to provide a uniform approach to the multifaceted nature of identities in terms of their bases, their processes, and their outcomes. In this paper, we discuss the similarities and differences between the two theories, and then offer a unified identity theory based on 21 theoretical definitions, assumptions, and heuristics. Following this, we demonstrate how the unified theory can be used to explain somewhat anomalous findings in two recent studies, one in the tradition of social identity theory and the other in the tradition of identity theory.