An examination of consequence probability as a determinant of precautionary intent
Desaulniers, David Roger
Laughery, Kenneth R., Sr.
Doctor of Philosophy
This study examined the relationship between consequence probabilities and decisions concerning self-protective behavior. The hypothesis put forth was that the probabilities associated with many common risks are at a level at which variations in probability have little influence on risk decisions. Subjects were presented with hypothetical risk situations in which consequence probability, consequence severity, and the costs of precautionary actions were explicitly stated and systematically manipulated. Decisions concerning the likelihood of taking a specific precautionary action in response to these risks were examined as a function of these three factors. The results revealed a "probability equivalence" effect, ranges of probabilities over which precautionary intent was essentially invariant, and that these ranges were highly dependent on consequence severity. In general, precautionary intent decreased as a function of decreasing consequence probability. However, for situations with low consequence severity, precautionary intent began to stabilize, trending towards an apparent minimum at low probability levels. Increasing consequence severity also had the effect of decreasing the "probability threshold", the probability level below which subjects were unlikely to take precautionary action. Increasing precautionary costs was also found to consistently depress willingness to take precautions. Precautionary intent was also examined as a function of several characteristics of the decision makers. Most scenarios revealed that levels of precautionary intent increased with age. In addition, in more than half of the scenarios, males were less inclined to take precautions than females. Analyses at the individual subject level revealed considerable variability in probability threshold and equivalence effects, indicating that the use of probabilities in risk decisions is highly dependent on the characteristics of the decision maker and the risk situation. Collectively the findings support the notion that probability information can influence decisions concerning precautionary intent, but that the probability equivalence effect may render consequence probability a poor discriminator when judgments are made concerning similar risks. The results suggest that the probability effects were products of subjects' informal cost-benefit analyses as opposed to a failure to perceive meaningful differences in the probabilities.
Experimental psychology; Social psychology