Imagining Can Heighten or Lower the Perceived Likelihood of Contracting a Disease

Prior research has demonstrated that imagining hypothetical future events may render those events subjectively more likely. The suggestion has been made that this effect is due to the increased availability in memory of the events imagined. To test directly this explanation in a health context, the present study examined the effects of both ease and difficulty of imagining contracting a disease on subjects' beliefs that the event would occur. Subjects were asked to imagine contracting a disease described either as having certain easy-to-imagine symptoms or difficult-to-imagine symptoms. Following this, subjects rated their ease of imagination and estimated the likelihood of contracting the disease. The results revealed that judgments of ease or difficulty of imagination paralleled judgments of the likelihood of contracting the disease. Those subjects who rated the disease as easy-to-imagine judged the disease as more likely to occur, whereas those who experienced difficulty in imagining the disease rated it as less likely to occur. The results are interpreted in terms of the availability heuristic and give direct support for and extend this principle by showing that trying to imagine difficult-to-construct or cognitively inaccessible events reduces likelihood estimates. Implications for preventive health programs are discussed.