(This is just a sketch argument, in response to the ideas from this popular NYT piece. I haven’t read the more technical literature in this area — start here. Hopefully my two main points are clear enough. I’m clearing my ideas backlog. . . .)
The notion that reasoning evolved to help us win arguments rather than to discover facts / truths is appealing, in part because it explains the persistence of cognitive biases as something other than defects. However, it can’t be true in the categorical way that its proponents state it. If arguments were just “to win,” instead of referring at some level to facts of the matter, there’d be no reason to listen to them — but their ability “to win” depends on people listening. Likewise, successful forms of argument are often truth-preserving ones — not always, but often, and “often” is enough to invalidate strong statements of the argumentative thesis.
Furthermore, the class of cognitive biases that can really be explained by the argumentative theory is quite restricted. In brief, it can only explain a bias that disproportionately favors a person’s own side in arguments. Many biases are neutral in the sense that, when you are having an argument and one side is favored by a cognitive bias, you will find yourself arguing against it roughly half the time.
EDIT: I think a good gloss on my first argument above is to say that the “argumentative” function has to be parasitic on the communicative / truth-seeking function. A parasite can’t kill its host (too often / quickly).
EDIT EDIT (6/24 11:50am): on reading something other than press reports on this, it seems to me the argumentative theory is much more measured and, well, boring than I’d been assuming based on the Times report. Some quotations from Hugo Mercier at his homepage:
the argumentative theory of reasoning—proposes that instead of having a purely individual function, reasoning has a social and, more specifically, argumentative function. The function of reasoning would be to find and evaluate reasons in dialogic contexts—more plainly, to argue with others. Here’s a very quick summary of the evolutionary rationale behind this theory. Communication is hugely important for humans, and there is good reason to believe that this has been the case throughout our evolution, as different types of collaborative—and therefore communicative—activities already played a big role in our ancestors’ lives (hunting, collecting, raising children, etc.). However, for communication to be possible, listeners have to have ways to discriminate reliable, trustworthy information from potentially dangerous information—otherwise speakers would be wont to abuse them through lies and deception. Listeners must have mechanisms of epistemic vigilance. [. . .]
Our evolutionary account is much more in touch with the prevailing view of the evolution of human cognition. According to this view—alternatively named the social brain hypothesis, or the Machiavellian intelligence hypothesis, among others—most of human cognition evolved to answer the demands of our social world. [. . .]
the argumentative theory of reasoning also fits in well, and helps make sense of, the recent developments in deliberative democracy. Deliberative democracy—basically, the idea that more political decisions should be the outcome of deliberation, that citizens should deliberate more—is one of the most potent ideas in current political science. Our theory explains well why deliberation should be a very efficient tool. [. . .]
Upshot. Reasoning is made for arguing. Because of this people have a strong confirmation bias that plagues lone reasoners. But when people argue, the biases of the arguers can balance each other out and lead reasoning to felicitous outcomes. Let’s reason together!
The theory is mostly about reasoning as a social-context rather than an individual-context ability. The theory doesn’t take a position on the balance between “lawyering” and “science” as evolutionary drivers of reasoning skill (the proposition we’ve been debating below, I think).
Put in the context of my original post, other people use their reasoning abilities to try to convince you of things. You listen because in the social-group context sometimes these things will be helpful to you (i.e., because true, or pro-coordination, etc.). Your exercise of “epistemic vigilance” makes it safe and worthwhile to listen — epistemic vigilance means evaluating the validity and plausibility of arguments (something you wouldn’t need to do if they were pure peacock displays, btw). Pretty chill, and pretty far from the extreme view I was originally criticizing.
Now, it doesn’t help that Mercier turned around and said practically the opposite thing to the New York Times:
“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.
What a cock. He’s allowing the Times report to sensationally characterize his theory such that “truth and accuracy are beside the point.” Yeah so that’s Mercier in the Times. Here again is Mercier on his homepage:
The speaker gives a reason to accept a given conclusion. The listener can then evaluate this reason to decide whether she should accept the conclusion. In both cases, they have used reasoning—to find and evaluate a reason respectively. If reasoning does its job properly, communication has been improved: a true conclusion is more likely to be supported by good arguments, and therefore accepted, thereby making both the speaker—who managed to convince the listener—and the listener—who acquired a potentially valuable piece of information—better off.
The discussion we were having here was interesting, and there was more I wanted to say, but reading Mercier has made me pretty apathetic about the whole thing.