Thinking One's Abilities Are Unique and One's Opinions Are Common

College students stated, in writing, their best ability and then estimated the percentage of their peers who are very good at the same activity. Other students stated a personally important opinion and either estimated the percentage of their fellows who would agree with it or estimated the percentage who hold the same position that they hold. The stated abilities and opinions were listed verbatim on separate sheets and given to other students;, for each item on the list, they made the same exact type of estimate as that made by those who generated the statements. As predicted, subjects underestimated the frequency of their own best ability among their peers relative to the "average "other's estimate of the frequency of that ability, but overestimated the frequency with which their fellows would agree with their own opinion relative to the "average" other's estimate of the frequency of that agreement. Subjects tended to underestimate the percentage who hold the same opinion they hold. Discussion focuses on a self-enhancement explanation as well as alternatives to it.