Individual differences in overconfidence: A common core and its motivational and cognitive correlates

Judgment and decision making research has typically not explicitly considered whether there are individual differences in overconfidence. When correlations among individual measures are reported, the strength of associations tends to be modest. Despite this, we show that when using the methods of individual differences research to analyze measures of overconfidence, there is substantial evidence for reliable, trait-level overconfidence-which we call 'core overconfidence'-that is stable over both short and long time periods. Moreover, three forms of overconfidence have primarily been studied: overestimation, overplacement, and overprecision. We find individual differences in each form, and that the different forms share a common core, supporting the conceptualization of overconfidence as a stable, multifaceted trait. Differences in both self-views and in 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. These relationships are generally explained distinctly by either a relationship with confidence or accuracy. In additional studies, we find that individual differences in overconfidence are robust even when minimizing the correlations in accuracy across tasks, demonstrating that they are not specific to self-views in a narrow domain. Overall, by studying the same respondents' behaviors across domains, forms of overconfidence, and time periods, we find strong evidence that overconfidence is a stable, multifaceted trait that can be explained by common motivated and cognitive processes.