Understanding identity integration: Theoretical, methodological, and applied issues.

Identity integration is one of the foundational theoretical concepts in Erikson's (1968) theory of lifespan development. However, the topic is understudied relative to its theoretical and practical importance. The extant research is limited in quantity and scope, and there is considerable heterogeneity in how identity integration is conceptualized and measured. Accordingly, the purpose of this paper is to 1) provide a conceptual discussion of different forms of identity integration 2) highlight the different methodological approaches represented in the literature, and 3) detail the implications of integration for psychological functioning. In particular, we provide a conceptual and methodological discussion of four forms of integration: two that are widely recognized, contextual integration and temporal integration, and two that have received less attention, ego integration and person-society integration. We see this paper as filling a need in the literature for those interested in how complex identity processes are related to psychological functioning.