According to a New York Times article, cognitive scientists Hugo Mercier and Dan Sperber have a new theory about rational argument: humans didn’t develop it in order to learn about the world, we developed it in order to win arguments with other people. “It was a purely social phenomenon. It evolved to help us convince others and to be careful when others try to convince us.”
Based on the NYT article, it seems that Mercier and Sperber are basically flipping around the traditional argument, which is that humans learned to reason about the world, albeit imperfectly, and learned to use language to convey that reasoning to others. These guys would suggest that it’s the other way around: we learned to argue with others, and this has gradually led to the ability to actually make (and recognize) sound arguments, but only indirectly. The article says “”At least in some cultural contexts, this results in a kind of arms race towards greater sophistication in the production and evaluation of arguments,” they write. “When people are motivated to reason, they do a better job at accepting only sound arguments, which is quite generally to their advantage.”
Of course I have no idea if any of this is true, or even how to test it. But it’s definitely true that people are often convinced by wrong or even crazy arguments, and they (we) are subject to confirmation bias and availability bias and all sorts of other systematic biases. One thing that bothers me especially is that a lot of people are simply indifferent to facts and rationality when making decisions. Mercier and Sperber have at least made a decent attempt to explain why people are like this.