Direct and indirect effects of agreeableness on overconfidence

Agreeableness is generally thought to be a personality trait with positive outcomes, especially with regards to the creation and maintenance of harmonious interpersonal relationships. The potential negative consequences of agreeableness are discussed less often. This study explores the potential for overconfidence among agreeable people. In addition, self-esteem and perceived similarity were examined as an explanation for the indirect effects of agreeableness on overconfidence. Specifically, within each pair of 104 student dyads who had worked jointly on a project in an undergraduate course, one acted as a rater and the other as a ratee. The raters were asked to evaluate their partner's performance, while the ratees were asked how they thought the raters had evaluated their performance. Our measure of overconfidence was the gap between the partner's evaluation of the participant's performance and the participant's belief in how this performance was evaluated. Additional measures filled out by the subjects included agreeableness, friendship, self-esteem, and perceived similarity. Results indicated that self-esteem and perceived similarity provide an approach for understanding the indirect effects of the agreeableness-overconfidence association.