Recent years have seen an explosion of research into the physiological and neural bases of social behavior. This state-of-the science handbook is unique in approaching the topic from a developmental perspective. Exploring the dynamic relationship between biology and social behavior from infancy through adolescence, leading investigators discuss key processes in typical and atypical development. Chapters address emotion, motivation, person perception, interpersonal relationships, developmental disorders, and psychopathology. The volume sheds light on how complex social abilities emerge from basic brain circuits, whether there are elements of social behavior that are "hard wired" in the brain, and the impact of early experiences. Illustrations include 8 color plates.