Mercier & Sperber made a similar argument, commenting that e.g. things that seem like biases in the context of a single individual (such as confirmation bias) are actually beneficial for the decision-making of a group. An excerpt:

... the idea that the confirmation bias is a normal feature of reasoning that plays a role in the production of arguments may seem surprising in light of the poor outcomes it has been claimed to cause. Conservatism in science is one example (see Nickerson 1998 and references therein). Another is the related phenomenon of groupthink, which has been held responsible for many disasters, from the Bay of Pigs fiasco (Janis 1982) to the tragedy of the Challenger shuttle (Esser & Lindoerfer 1989; Moorhead et al. 1991) (for review, see Esser 1998). In such cases, reasoning tends not to be used in its normal context: that is, the resolution of a disagreement through discussion. When one is alone or with people who hold similar views, one’s arguments will not be critically evaluated. This is when the confirmation bias is most likely to lead to poor outcomes. However, when reasoning is used in a more felicitous context – that is, in arguments among people who disagree but have a common interest in the truth – the confirmation bias contributes to an effi- cient form of division of cognitive labor.

When a group has to solve a problem, it is much more efficient if each individual looks mostly for arguments supporting a given solution. They can then present these arguments to the group, to be tested by the other members. This method will work as long as people can be swayed by good arguments, and the results reviewed in section 2 show that this is generally the case. This joint dialogic approach is much more efficient than one where each individual on his or her own has to examine all possible solutions carefully.8 The advantages of the confirmation bias are even more obvious given that each participant in a discussion is often in a better position to look for arguments in favor of his or her favored solution (situations of asymmetrical information). So group discussions provide a much more effi- cient way of holding the confirmation bias in check. By contrast, the teaching of critical thinking skills, which is supposed to help us overcome the bias on a purely individual basis, does not seem to yield very good results (Ritchart & Perkins 2005; Willingham 2008).

For the confirmation bias to play an optimal role in discussions and group performance, it should be active only in the production of arguments and not in their evaluation. Of course, in the back-and-forth of a discussion, the production of one’s own arguments and the evaluation of those of the interlocutor may interfere with each other, making it hard to properly assess the two processes independently. Still, the evidence reviewed in section 2.1 on the understanding of arguments strongly suggests that people tend to be more objective in evaluation than in production. If this were not the case, the success of group reasoning reviewed in section 2.3 would be very hard to explain.