The trouble with overconfidence. (2008)

“On difficult tasks, people overestimate their performance but also mistakenly believe that they are worse than others. On easy tasks, people underestimate their actual performances but mistakenly believe they are better than others.

Moore, D.A., Carnegie Mellon University,
Healy, P.J., Ohio State University

Psychological Review 115: 502-517.

The authors present a reconciliation of three distinct ways in which the research literature has defined overconfidence

First, overestimation of one’s actual performance, second overplacement of one’s performance relative to others, and third, excessive precision in one’s beliefs.

Experimental evidence shows that reversals of the first two (apparent underconfidence) when they occur, tend to be on different types of tasks. On difficult tasks, people overestimate their actual performances but also mistakenly believe that they are worse than others. On easy tasks, people underestimate their actual performances but mistakenly believe they are better than others.

The authors offer a straightforward theory that can explain these inconsistencies. Overprecision appears to be more persistent than either of the other two types of overconfidence, but its presence reduces the magnitude of both overestimation and overplacement.

Access the full paper here: The trouble with overconfidence