Two studies examined the accuracy of personal risk estimates, as determined by comparing mean estimates made by college students with population statistics for college-educated individuals. Study 1 suggested that optimistic biases (the tendency for people to think they are less at risk than the average person) arise more because people overestimating the average person's risk than because they underestimate their own risk. In Study 2, subjects rated their risk after being presented with risk statistics that were 150%, 100%, or 50% of the true values. Subjects' estimates decreased with decreases in the comparison statistics, as if subjects attempted to preserve their “below-average” status, but they changed less than did the statistics and were actually pessimistic in comparison to the 50% values. Implications for interventions designed to influence risk perceptions are discussed.