Extant studies of age differences in cognitive processes relevant to risk taking and decision making, such as risk perception and risk appraisal, indicate few significant age differences in factors that might explain why adolescents engage in more risk taking than adults. The present analysis suggests that the greater propensity of adolescents to take risks is not due to age differences in risk perception or appraisal, but to age differences in psychosocial factors that influence self-regulation. It is argued that adolescence is a period of heightened vulnerability to risk taking because of a disjunction between novelty and sensation seeking (both of which increase dramatically at puberty) and the development of self-regulatory competence (which does not fully mature until early adulthood). This disjunction is biologically driven, normative, and unlikely to be remedied through educational interventions designed to change adolescents' perception, appraisal, or understanding of risk. Interventions should begin from the premise that adolescents are inherently more likely than adults to take risks, and should focus on reducing the harm associated with risk-taking behavior.