ABSTRACT
Cross-cultural and anthropological studies are important for developmental psychology because they provide a unique kind of window on the process of human development. They offer the best evidence we can find for determining what are the transhuman universals, as well as the manifold cultural variations, for any given area of growth and development. When one examines what we know about human behavior around the world, especially when focusing on infants and children, one cannot but see evidence for the psychic unity of mankind, the postulate that all human beings obey the same psychological laws and think in ways that are ultimately understandable, or "commensurable," one to another. Yet, at the same time, cultural specificities—though difficult to precisely define and to quantify—challenge us to construct valid generalizations about the effects of environment on child development by determining how to assess the most significant dimensions of children's developmental niches worldwide.
