Affect, generalization, and the perception of risk.

Experimental manipulations of affect induced by a brief newspaper report of a tragic event produced a pervasive increase in subjects' estimates of the frequency of many risks and other undesirable events. Contrary to expectation, the effect was independent of the similarity between the report arid the estimated risk. An account of a fatal stabbing did not increase the frequency estimate of a closely related risk, homicide, more than the estimates of unrelated risks such as natural hazards. An account of a happy event that created positive affect produced a comparable global decrease in judged frequency of risks. As a society, we have never been more concerned with the assessment, the management, and the regulation of risk. Because public reaction to hazards from pesticides, nuclear power, or food additives appears to influence the regulation and management of these technologies, it is important to understand how the lay person perceives and evaluates risks. This is particularly true for hazards such as terrorism, nuclear power, or genetic engineering for which the available statistical data are very limited and where the assessments of the risks are based on subjective and intuitive judgments. Indeed, psychologists and other researchers have shown increasing interest in the manner in which people perceive and estimate the severity of various risks. Lichtenstein, Slovic, Fischhoff, Layman, and Combs (1978) asked lay people to estimate the number of deaths per year that are due to various hazards. These investigators found that the subjective estimates were consistent across several methods of elicitation and correlated reasonably well (median r = .7) with actuarial estimates of frequency. A comparison of objective and subjective estimates revealed two