All people derive their identities from the groups and social categories to which they belong in society, the roles they play out, and their personal characteristics they claim. Introduced more than fifty years ago, identity theory has become a central theoretical perspective in sociological social psychology. Now in a greatly expanded second edition, Identity Theory attempts to explain identities, their processes of operation, and their sources in and consequences for interaction and society. This book describes the origins of identity theory, its development, the research that supports it, and its future direction. It covers the central roles of meaning and resources in human interaction and purpose. It provides a detailed analysis of the nature and operation of identities. A central aspect of identities, identity verification, is discussed in terms of how it works, and its consequences for individuals. In addition, the book discusses the different bases of identities, and the multiple identities that individuals hold from their multiple positions in society. It also covers the way identities offer both stability and change to individuals. Coauthored by the originators of the theory, this book accessibly presents decades of research in a single volume, making the full range of this powerful theory understandable to readers at all levels.