In the past decade, an increasing volume of psychological research has been conducted on social exclusion by social and developmental psychologists. The very best of this new body of work is showcased in this volume, providing an understanding of how children experience, evaluate, and understand exclusion as well as inclusion. For interventions to be effective, programs designed to ameliorate social problems associated with exclusion need to be based on an understanding of how, why, and under what conditions, social groups make decisions to exclude others, how children experience this exclusion, and how this originates and changes over the course of the lifespan. This volume draws together and foregrounds social and developmental psychological research to show its central relevance to the social exclusion of children.