The link between judgements of comparative risk and own risk: Further evidence

Individuals typically believe that they are less likely than the average person to experience negative events, a phenomenon termed “unrealistic optimism”. The direct method of assessing unrealistic optimism employs a question of the form, “Compared with the average person, what is the chance that X will occur to you?”. However, it has been proposed that responses to such a question (direct-estimates) are based essentially just on estimates that X will occur to the self (self-estimates). If this is so, any factors that affect one of these estimates should also affect the other. This prediction was tested in two experiments. In each, direct- and self-estimates for an unfamiliar health threat—homocysteine-related heart problems—were recorded. It was found that both types of estimate were affected in the same way by varying the stated probability of having unsafe levels of homocysteine (Study 1, N = 149) and varying the stated probability that unsafe levels of homocysteine will lead to heart problems (Study 2, N = 111). The results are consistent with the proposal that direct-estimates are constructed just from self-estimates.