Relative contribution of likelihood and severity of injury to risk perceptions

John W. Brelsford, Jr. Dept. of Psychology Rice University Houston, TX 77005 The degree of caution that people are willing to take for a given product is largely determined by their perceptions of the risk associated with that product. Research suggests that risk perceptions are determined by the objective likelihood or probability of encountering potential hazards (Slovic, Fischhoff, and Lichtenstein. 1979). However, there is also research suggesting lhalobjeclive likelihood plays little or no role in determining risk perceptions. Rather, risk is determined by the subjective dimension of the hazard or in other words, the severity of injury (Wogalter. Desaulniers and Brelsford. 1986. 1987). The present research ex.amined aspects of these two studies in an attempt to reconcile the observed differences. Subjects evaluated either the Wogalter et al. (1986, 1987) products or the Siovic et al. (1979) items on eight rating questions. Results demonstrated that severity of injury was the foremost predictor of perceived risk for the Wogalter products, but tJlat likelihood of injury was primarily responsible for ratings of risk for fue Siovic items. The two lists differed substantially on all fue dimensions evaluated. suggesting that the content of the lists is responsible for the contrary findings. In a second study, subjects rated another set of generic consumer products. These ratings showed a pattern of results similar to the Wogalter products. Overall, this research: (a) ex.plains the basis for conflicting results in fue risk perception literature, and (b) demonstrates that severity of injury, and not likelihood of injury, is the primary determinant of people's perceptions of risk for common consumer products.