Fig. 3: Calibration analysis (i.e., degree of fit between a person’s judgment of performance and his or her actual performance).

Participants’ metacognition was not calibrated for estimating the probability of news veracity. The confidence-accuracy calibration plot displays the participants’ accuracy in estimating probabilities that their judgment was correct as a function of their confidence level. Well-calibrated estimated probabilities would intersect with confidence degrees in the grey area, meaning, for example, that a 0–20% confidence degree predicts a 0–20% accuracy in evaluating news veracity. The plot shows that overall, the proportion of accurate veracity estimations did not increase nor decrease with confidence. Furthermore, the plot emphasizes that accuracy is higher for true news than for false news (the green curve always lies above the red one). Underconfidence dominates for true news whereas overconfidence dominates for false news. Note: n = 258.