The Laws of Fear

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. In the late 1980s, the Environmental Protection Agency embarked on an ambitious project, designed to compare the views of “the public” and “EPA experts” on the seriousness of environmental problems.1 The project revealed some striking anomalies, for the two groups sharply diverged on some crucial issues. With respect to health risks, the public’s top five concerns included radioactive waste, radiation from nuclear accidents, industrial pollution of waterways, and hazardous waste sites.2 But in the view of EPA experts, not one of these problems deserved a “high” level of concern. Two of the public’s top concerns (nuclear accident radiation and radioactive waste) were not even * Karl N. Llewellyn Distinguished Service Professor, Law School and Department of Political Science, University of Chicago. I am grateful to Daniel Kahneman, Martha Nussbaum, and Richard A. Posner for very helpful comments on a previous draft. 1 Counting on Science At EPA, 249 Science 616 (1990).