This volume brings together an outstanding group of scientists studying the behavioural development of primates between weaning and adulthood. The book begins by examining the nature of the juvenile period across the animal kingdom, continues with presentation of new data on the behaviour and social relationships of juvenile primates across a broad range of species, and concludes with applications of concepts in socioecology to research on children. The result is a landmark in primate studies, one that offers an important corrective to the idea that it is sufficient to concentrate on the life stages of adult and infant.