Imagining and Explaining Hypothetical Scenarios: Mediational Effects on the Subjective Likelihood of Health-Related Outcomes1


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    The authors thank Sarah Grugeon, Duncan Hedderley, and Karen Oltersdorf for their contribution to the research reported here and to the anonymous reviewers for their insightful comments on an earlier draft of the manuscript. The research was carried out as part of the project, “The Development of Models for Understanding and Predicting Consumer Food Choice” (AIR2 CT94 1315), funded by the European Union.

Correspondence concerning this article should be addressed to Paul Sparks, Department of Psychology, University of Sussex, Falmer, Brighton BN1 9SN, United Kingdom. E-mail:


Imagining and explaining hypothetical events have been shown to increase the subjective likelihood of those events occurring. At the same time, it has been suggested that reducing unrealistic optimism about health risks (i.e., increasing the subjective likelihood of negative health outcomes) might motivate health-protective behavior. In exploring the implications of these issues for health-promotion goals, 2 experiments (Ns= 334 and 328) involving postal questionnaires are reported in which attempts are made through the use of imagine-and-explain scenarios to manipulate the subjective likelihood of a negative outcome (heart disease) and of a positive outcome (reducing fat consumption). The greater success of the manipulation of dietary change expectations than of heart disease expectations suggests the potential benefits of focusing directly on planning goal strategies in relation to health beneficial behaviors.