The recent increase in emphasis on the impact of early childhood experience on subsequent human development constitutes a change in the conceptual framework of the study of early childhood development. Anyone who is interested in prevention and intervention needs to be aware of the particulars of the debate on the strengths and weaknesses of the new paradigm, and to address the issues raised by the new research on infancy. This article provides a brief sampling of aspects of the debate. The article: (1) describes the role of family needs and service overload in the social context of the debate; (2) reviews recent attachment research from Bowlby through Ainsworth to Belsky; (3) discusses the Strange Situation; and (4) considers the controversy about day care that Belsky's research has engendered. Belsky's findings led him to assert that day care, and particularly full-time day care (care of more than 20 hours per week), was a risk factor. Researchers criticized Belsky's work for its dependence on the Strange Situation procedure, for its use of an insufficient number of studies as the basis for a broad generalization, and for the policy implications of the generalization. An extensive bibliography is provided. (RH)