The Monkey Cage: "The Not Quite As Depressing Psychological Theory That Explains Washington":

In a landmark article in Behavioral and Brain Sciences, Hugo Mercier and Dan Sperber propose an “argumentative” theory of human reason which both directly acknowledges the problems of motivated reasoning and suggests that motivated reasoning in the right social contexts can be incredibly valuable and powerful.

Mercier and Sperber have a straightforward account of why human beings reason. They reason to win arguments by convincing others that they are right. This means that human beings suffer from “confirmation bias.” They are far, far better at finding justifications for why they are right than they are at thinking carefully about reasons why they might be wrong. [...]

However, where Mercier and Sperber depart from the skeptics is in pointing to the social value of reasoning. People are terrible judges of the flaws and weaknesses of their own arguments. However, they are much, much better at identifying weaknesses in the arguments of others. Furthermore, confirmation bias gives them good reason not only to try to confirm their own arguments, but also to try to demolish the arguments of people who disagree with them. This in turn means that groups — under the right conditions — are likely to be able to reach better judgments than any individual within the group. Real, substantial argument allows a kind of cognitive division of labor, in which different arguments get tested against each other.

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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 . . . show that this is generally the case.