The Missing Variable: Identity Group Theory and the Search for a Common Language in the Social Sciences

Abstract

Over the past half-century, identity has emerged as a central concern across the social sciences. Psychologists examine identity development and salience, sociologists investigate collective identities and social reproduction, economists increasingly recognise identity as a determinant of behaviour, political scientists analyse identity mobilisation and conflict, while anthropologists and cultural theorists explore the symbolic production of belonging. Despite this convergence, these disciplines continue to conceptualise identity through distinct theoretical vocabularies, resulting in fragmented explanations of related social phenomena.
This article argues that identity itself has become the missing integrative variable in contemporary social science. Rather than proposing another discipline-specific theory of identity, it introduces Identity Group Theory (IGT) as a general analytical framework capable of linking existing approaches while preserving their methodological diversity. The article identifies four recurrent analytical dimensions that appear, often implicitly, across the social sciences: identity narratives, through which groups define meaning and belonging; identity regulation, through which norms and sanctions maintain group boundaries; identity economies, through which scarce symbolic and material resources are allocated; and identity allocation, through which individuals distribute finite time and energy across competing social affiliations.
By demonstrating how these concepts provide a common vocabulary for analysing motivation, institutions, discourse, cooperation, conflict, and social change, the article proposes a research programme rather than a closed theoretical system. Its objective is not to replace disciplinary perspectives but to facilitate cumulative knowledge across them by identifying shared mechanisms underlying apparently disparate phenomena. The article concludes by outlining a collaborative agenda through which psychology, sociology, economics, political science, anthropology, communication studies, and related disciplines can contribute to the empirical development of Identity Group Theory.