Overconfidence in personnel selection: When and why unstructured interview information can hurt hiring decisions

•Individuals responsible for hiring decisions participated in two studies.•We manipulated the information presented to them.•Information about unstructured interviews boosted overconfidence.•A third study showed that overconfidence was linked to fewer payoffs.•In the presence of valid predictors, unstructured interviews can hurt hiring decisions.

Overconfidence is an important bias related to the ability to recognize the limits of one’s knowledge. The present study examines overconfidence in predictions of job performance for participants presented with information about candidates based solely on standardized tests versus those who also were presented with unstructured interview information. We conducted two studies with individuals responsible for hiring decisions. Results showed that individuals presented with interview information exhibited more overconfidence than individuals presented with test scores only. In a third study, consisting of a betting competition for undergraduate students, larger overconfidence was related to fewer payoffs. These combined results emphasize the importance of studying confidence and decision-related variables in selection decisions. Furthermore, while previous research has shown that the predictive validity of unstructured interviews is low, this study provides compelling evidence that they not only fail to help personnel selection decisions, but can actually hurt them.