From an old Edge discussion:

Last July, opening the Edge Seminar, “The New Science of Morality”, Jonathan Haidt digressed to talk about two recently-published papers in Behavioral and Brain Sciences which he believed were “so important that the abstracts from them should be posted in psychology departments all over the country.”

One of the papers “Why Do Humans Reason? Arguments for an Argumentative Theory,” published by Behavioral and Brain Sciences, was by Hugo Mercier and Dan Sperber.

“The article,” Haidt said, “is a review of a puzzle that has bedeviled researchers in cognitive psychology and social cognition for a long time. The puzzle is, why are humans so amazingly bad at reasoning in some contexts, and so amazingly good in others?”

“Reasoning was not designed to pursue the truth. Reasoning was designed by evolution to help us win arguments. That’s why they call it The Argumentative Theory of Reasoning. So, as they put it, “The evidence reviewed here shows not only that reasoning falls quite short of reliably delivering rational beliefs and rational decisions. It may even be, in a variety of cases, detrimental to rationality. Reasoning can lead to poor outcomes, not because humans are bad at it, but because they systematically strive for arguments that justify their beliefs or their actions. This explains the confirmation bias, motivated reasoning, and reason-based choice, among other things.”

“Now, the authors point out that we can and do re-use our reasoning abilities. We’re sitting here at a conference. We’re reasoning together. We can re-use our argumentative reasoning for other purposes. But even there, it shows the marks of its heritage. Even there, our thought processes tend towards confirmation of our own ideas. Science works very well as a social process, when we can come together and find flaws in each other’s reasoning. We can’t find the problems in our own reasoning very well. But, that’s what other people are for, is to criticize us. And together, we hope the truth comes out.”

…The paper has created a storm of interest and controversy and has has attracted attention well beyond academic circles. Sharon Begley (Newsweek) and Jonah Lehrer (Wired) were among the many journalists who wrote stories.  In addition, many leading thinkers have taken note.

Gerd Gigerenzer finds this view on reasoning is most provocative as “reasoning is not about truth but about convincing others when trust alone is not enough. Doing so may seem irrational, but it is in fact social intelligence at its best.” Steven Pinker notes that “The Argumentative Theory is original and provocative, has a large degree of support, and is strikingly relevant to contemporary affairs, including political discourse, higher education, and the nature of reason and rationality. It is likely to have a big impact on our understanding of ourselves and current affairs.”

And Jonathan Haidt says the “the article is one of my favorite papers of the last ten years. I believe that they have solved one of the most important and longstanding puzzles in psychology: why are we so good at reasoning in some cases, but so hopelessly biased in others? Once I read their paper, I saw the argumentative function” of reasoning everywhere — particularly in the reasoning of people I disagreed with, but also occasionally even in myself. They’re on to a very powerful idea with many social and educational ramifications.”

Read an interview with one of the paper’s authors – Hugo Mercier – here: http://www.edge.org/documents/archive/edge.org/conversation/the-argumentative-theory