Abstract: Why do adolescents take risks? What is the appropriate response to adolescent risk-taking? This Commentary for a special issue of Developmental Review, discussing a set of papers in that issue, explores these questions with attention to changes in the adolescent brain, to dual-processing theory, to social influences, and to fuzzy-trace theory. It contends that adolescent risk-taking is often driven by the social meaning of risk and caution, and that social meaning operates as a tax on or a subsidy to behavior. Changes in social meaning present a serious collective action problem, but also a valuable opportunity for both law and policy.