Unrealistic optimism about becoming infected with HIV: different causes in different populations

People tend to believe that their chance of experiencing undesirable events is lower and their chance of experiencing desirable events is higher than that of the average person like them. Two explanatory models of such 'unrealistic optimism' (UO) have been proposed: While the motivational account holds that UO serves the function of bringing comfort, the cognitive account holds that UO serves no particular function, being simply a by-product of normal cognitive strategies. UO for HIV infection was studied in samples of uninfected students (Study 1, n = 68) and gay men (Study 2, n = 63). In each case, participants rated either their relative likelihood of becoming infected (negative valence condition) or their relative likelihood of remaining uninfected (positive valence condition). As predicted, in Study 1 UO was greater where valence was negative and in Study 2 valence had no effect. The findings suggest that the students' UO is better explained by the motivational account, while the gay men's UO is better explained by the cognitive account. Implications for AIDS education are discussed.<br />