Aging and integration of contingency evidence in causal judgment.

Age differences in causal judgment are consistently greater for preventative/negative relationships than for generative/positive relationships. In this study, a feature analytic procedure (Mandel & Lehman, 1998) was used to determine whether this effect might be due to differences in young and older adults' integration of contingency evidence during causal induction. To reduce the impact of age-related changes in learning/memory, the authors presented contingency evidence for preventative, noncontingent, and generative relationships in summary form; the meaningfulness of causal context was varied to induce participants to integrate greater or lesser amounts of this evidence. Young adults showed greater flexibility in their integration processes than did older adults. In an abstract causal context, there were no age differences in causal judgment or integration, but in meaningful contexts, young adults' judgments for preventative relationships were more accurate than older adults' and young adults assigned more weight to the contingency evidence confirming these relationships. These differences were mediated by age-related changes in processing speed. The decline in this basic cognitive resource may place boundaries on the amount or type of evidence that older adults can integrate for causal judgment.