Dynamic modulation of confidence based on the metacognitive skills of collaborators.

In collaborative decision-making contexts, people typically share their metacognitive experience of confidence to convey the degree of certainty in their decisions. To reach collective decisions, collaborators' individual beliefs can be aggregated and weighted according to their respective confidence, thereby enhancing group accuracy beyond individual capabilities. Previous joint decision-making studies have shown that individuals tend to adopt the same scale for communicating their levels of confidence. However, confidence judgments vary not only in terms of metacognitive bias, that is whether individuals tend to report generally low or high confidence, but also in terms of metacognitive accuracy, or how well the confidence judgments align with choice accuracy. In the first two experiments, where the metacognitive accuracy of the collaborator was manipulated and explicitly communicated to participants, individuals increased their average confidence levels as the metacognitive accuracy of the collaborator decreased, while their own metacognitive accuracy remained unaffected. Trial-wise analyses showed that participants differentially adapted their confidence after a collaborator made a wrong group decision, depending on the metacognitive accuracy of the collaborator. In two follow up studies, we showed that both manipulations (i.e. manipulating objective differences in the metacognitive accuracies of the collaborators and explicitly communicating these differences) were necessary for these effects to emerge. Our findings shed light on how collaborative decision-making contexts can dynamically affect metacognitive processes.