Cognitive and social psychologists have uncovered a number of features of ordinary thinking about risk. Giving particular attention to the work of Paul Slovic, this review-essay explores how an understanding of human cognition bears on law and public policy. The basic conclusion is that people make many mistakes in thinking about risk and that sensible policies, and sensible law, will follow statistical evidence, not ordinary people. The discussion explores the use of heuristics, the effects of cascades, the role of emotions, demographic differences, the role of trust, and the possibility that ordinary people have a special “rationality” distinct from that of experts. Because people are prone to error, what matters, most of the time, is actual risk, not perceived risk
