自信があれば後悔しない

—意思決定への自信が後悔に与える影響—

抄録

This study investigates the relationship between confidence and regret. We predicted that high levels of confidence—where confidence is defined as reduced counterfactual thinking—would limit the experience of regret. A previous study by Gilovich & Medvec (1995) found an action/inaction effect, where regret is higher when one fails to act. However, this effect may no longer exist once we conceptually distinguish the decision to act from one's confidence about that decision. The decision to act is usually accompanied with a high level of confidence, and little counterfactual thinking. We hypothesized that regardless of action/inaction, regret will be significantly lower when a decision is made with high confidence. In Experiment 1, participants read a series of scenarios and made a decision. Before receiving feedback on their decision, participants rated their level of confidence about the decision. In Experiment 2, participants read a hypothetical mistake made by an individual and estimated that individual's level of regret. The results support our hypothesis that level of confidence about decisions affects feelings of regret.