Research on parenting through the life course has developed around two separate approaches. Evolutionary biology provides fresh perspectives from life history theory using behavioral ecology and parental investment theory. At the same time, the social and behavioral sciences integrates research from long-term studies of individual development and from the collection of life histories. This path-breaking book advances evolutionary, life history research by integrating perspectives of these two approaches into a biosocial science of the life course. It examines parenthood as a commitment extending throughout life and focuses on the impact on parental and child behavior of changes in the timing, distribution, and intensity of parental investment. This perspective is particularly appropriate for research on parenting since the family is the universal human institution within which the bearing and rearing of children has been based and which transmits traditions, beliefs, and values to the young.