Wise Up: Clarifying the Role of Metacognition in the Dunning-Kruger Effect

The Dunning-Kruger effect (DKE) is the finding that, across a wide range of tasks, poor performers greatly overestimate their ability, whereas top performers make more accurate self-assessments. The original account of the DKE involves the idea that metacognitive insight requires the same skills as task performance, so that unskilled people perform poorly and lack insight. However, global measures of self-assessment are prone to statistical and other biases that could explain the same pattern. We used psychophysical methods to examine metacognitive insight in simple movement and spatial memory tasks: pointing at a dot or recalling its position after a delay. We measured task skill in an initial block, and self-assessment in a second block, in which participants judged after every trial whether they had hit the target or not. Metacognitive calibration and sensitivity were related to task skill, but a path analysis showed that their net contribution to the DKE was weak. The major driver of the DKE was the level of task performance. In a second study, we again measured task skill in an initial block, but titrated task difficulty in the second block so that all participants performed at equivalent levels of success. Metacognitive measures were again related to task skill, but the DKE pattern was eliminated. We present a simple model of these findings, showing that metacognitive differences can contribute to the DKE but are neither necessary nor sufficient for it. This analysis clarifies and quantifies how metacognitive insight and other factors interact to determine this famous effect.