This article reports on the relationship between outcome knowledge regarding an environmental event and self-reported fear of future illness. A sample of 95 subjects in three conditions showed that outcome knowledge increases post event likelihood estimations, thus indicating a hindsight bias. Subjects' perceived likelihood of increases in disease rate is shown to substantially predict subjects' level of fear of future illness for both cancer and no cancer disease. Demographic variables of gender, political ideology, and attitude toward environmental activism were shown to have mixed results in predicting fear of future illness. Positive attitude toward environmental activism modesty predicted fear of cancer but not fear of noncancer disease. Political ideology failed to significantly predict fear of future illness, although it showed a trend toward significance for predicting fear of cancer. Gender significantly predicted fear of noncancer disease but not fear of cancer, with females indicating more fear than males. The implications of the accuracy of outcome information following ambiguous and uncertain events on the genesis and exacerbation of fear of future illness is discussed.
