Perceived risk of tropical diseases in Malawi: Evidence of unrealistic pessimism and the irrelevance of beliefs of personal control?

Sociocognitive models of health preventative behaviour have rarely been applied in the developing world, despite their potential contribution in addressing major preventable health risks. One hundred and twenty individuals representative of the Malawian population were interviewed regarding beliefs about likelihood, severity, predictability and controllability of two prevalent tropical diseases - malaria and schistosomiasis. Data was also collected regarding adherence to recommended control practices for these two health risks. Subjects were drawn from two rural marshland locations. Results were interpreted in relation to an existing literature on unrealistic optimism, with subjects rating their personal risk as well as perceived risk for others. Across both locations and for both disease risks there was evidence of unrealistic pessimism in terms of their personal likelihood of infection. In one location unrealistic pessimism was further indicated by the rating of both diseases as less controllable by self than by others. Significant differences existed between the areas in terms of control practices. Adherence to control practices was associated with lower, rather than higher, ratings of predictability and controllability of health risk. These findings are interpreted with respect to recent analysis of the social function of optimistic bias across differing cultures, and the potential adaptive function of pessimism in settings with endemic health risk and control measures in part within the social, rather than the personal, domain.