A critical intervention into the ongoing and perpetually troubling nature-nurture debates surrounding human development. Originally published in 1985, in this revised edition Susan Oyama argues that nature and nurture are not alternative influences on human development but, rather, developmental products and the developmental processes that produce them. Information, says Oyama, is thought to reside in molecules, cells, tissues and the environment. When something wondrous occurs in the world, we tend to question whether the information guiding the transformation was pre-encoded in the organism or installed through experience or instruction. She shows that developmental information does depend on what is already in place and what alternatives are available. She terms this process "constructive interactionism", whereby each combination of genes and environmental influences simultaneously interact to produce an unpredictable result. Ontogeny, then, is the result of dynamic and complex interactions in multilevelled developmental systems.