Individual Differences in Overconfidence and their Psychological Bases

Judgment and decision making research has typically not explicitly considered whether there are individual differences in overconfidence. In cases where correlations among individual measures are reported, the strength of associations tends to be modest. Despite this, the authors show that when analyzing measures of overconfidence from an individual differences perspective, there is substantial evidence for trait-level overconfidence—which we call ‘core overconfidence’—that is stable over both short and long-time periods. Further, overconfidence has primarily been studied in one of three forms: overestimation, overplacement, or overprecision. The authors find that measures across these forms are consistently related when each form is measured reliably. These results are shown to be robust over a broad array of design and analytical choices. The authors also find evidence that differences in both self-enhancement and reflective cognitive processes appear to contribute to this stability: a range of individual difference measures (e.g., narcissism, actively open-minded thinking) significantly correlate with core overconfidence, though these relationships are generally explained distinctly by either a relationship with confidence or accuracy. In additional studies, the authors show that individual differences in overconfidence are robust when minimizing the correlations in accuracy across tasks, demonstrating that they are not specific to narrow self-views in a domain. Overall, by studying the same respondents’ behaviors across domains, forms, and time periods, the authors find strong evidence for stable, individual differences in overconfidence that are interpretable in terms of common motivated and cognitive processes.