For centuries thinkers have assumed that the uniquely human capacity for reasoning has existed to let people reach beyond mere perception and reflex in the search for truth. Rationality allowed a solitary thinker to blaze a path to philosophical, moral and scientific enlightenment.

Now some researchers are suggesting that reason evolved for a completely different purpose: to win arguments.
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“Reasoning doesn’t have this function of helping us to get better beliefs and make better decisions,” said Hugo Mercier, who is a co-author of the journal article, with Dan Sperber. “It was a purely social phenomenon. It evolved to help us convince others and to be careful when others try to convince us.” Truth and accuracy were beside the point.