Stable Individual Differences in Overconfidence

Overconfidence has primarily been studied in one of three forms; overestimation, overplacement, or overprecision. These forms differ in their definitions, the levels of overconfidence they exhibit, and their responses to changes to task difficulty. This has led some to conclude that the different measurements of overconfidence do not share a common, dispositional component, but rather are empirically distinct. In two time-lagged studies, we show that at an individual-level, i) different elicitations of overconfidence are positively correlated, and ii) measures of overconfidence are stable over short and long time periods. We conclude from this evidence that there is a dispositional component to overconfident beliefs and that the three forms are empirically related. We also introduce a new measure of overconfidence that is less dependent on the idiosyncrasies of individual elicitations: core overconfidence. We find that core overconfidence is significantly associated with a range of individual difference measures (e.g., narcissism), and can be measured efficiently using a short three-item scale. Overall, by studying the same respondents’ behaviors across elicitations, domains, and time periods, we find strong evidence for stable, individual differences in overconfidence.