The National Scientific Council on the Developing Child was founded to close the gap between what we know and what we do to promote the healthy development of young children. When scientific knowledge is ignored rather than used to inform early childhood policy and practices, our children pay a very high price. Council Chair Jack P. Shonkoff, M.D., discusses the goals of the Council and four key conclusions of science that can be used to guide policy: human development is as much a function of "nurture" as of "nature;" the essential influences on children's development are their relationships with their caregivers; the development of intelligence, language, emotions, and social skills are highly interrelated; and programs informed by scientific knowledge about child development can pay important dividends for the children and for society. [The interviewer for this report was Dorian Friedman.]