Organizations are groups. They compete with other groups; they are internally structured into subgroups and roles; and they influence and are influenced by social identity processes. This new volume is the first to bring together social and organizational psychologists to explore social identity theory in organizational contexts. The chapters are wide ranging - they deal with basic social identity theory, organizational diversity, leadership, employee turnover, mergers and acquisitions, organizational identification, cooperation and trust in organizations, commitment and work, and socialization and influence within organizations. This book is an integrative platform for a closer relationship between social psychologists and organizational psychologists who study social identity processes in organizations - a relationship that will fuel new directions in basic and applied social identity research, and will significantly advance our understanding of organizational life.