Social Identity explains how identification, seen as a social process, works: individually, interactionally and institutionally. Building on the international success of previous editions, this fourth edition offers a concise, comprehensive and readable critical introduction to social science theories of identity for advanced undergraduates and postgraduates. All the chapters have been updated, and extra new material has been added where relevant, integrating the most recent critical publications in the field. As with the earlier editions, the emphasis is on sociology, anthropology and social psychology; on the interplay between relationships of similarity and difference; on interaction; on the categorisation of others as well as self-identification; and on power, institutions and organisations. Written in clear, accessible language, and informed by relevant topical examples throughout, this fully updated new edition will be useful for students interested in social identity throughout the social sciences and humanities.