A theory of development from late teens through the twenties. The concept of childhood in the middle ages. Effect size, practical importance, and social policy for children. Joint involvement episodes as context for development. Developmental psychology, God, and the good.
Infants possess a system of numerical knowledge.
The case for nature and nurture. A dynamic constructivist to culture and cognition. Nature, nurture, and twin research strategies. Resolving the debate over birth order, family size, and intelligence.