Although science policy and social policy have distinct cultures, there are overlapping influences on both. Science policy decisions across the spectrum of basic and applied research are influenced by perceived social utility and the potential for solving current social problems. With the advent of evidence-based policy requirements, social policymakers increasingly use scientific information, although it constitutes only 1 factor in a mix of ideology, interests, and institutional constraints. The spread of early childhood intervention programs in the United States and elsewhere is one example in which strong, cumulative evidence has contributed to a policy consensus. Developmental scientists can contribute to better science policy and better social policy by strengthening the scientific quality of their evidence and communicating research-based knowledge more effectively.