This collection of articles is completely and explicitly devoted to the new field of comparative developmental evolutionary psychology–that is, to studies of primate abilities based on frameworks drawn from developmental psychology and evolutionary biology. These frameworks include Piagetian and neo-Piagetian models as well as psycholinguistic ones. The articles in this collection–originating in Japan, Spain, Italy, France, Canada, and the United States–represent a variety of backgrounds in human and nonhuman primate research. The authors focus on such areas as the nature of culture, intelligence, language, and imitation; the differences among species in mental abilities and developmental patterns; and the evolution of life histories and of mental abilities and their neurological bases.