Interesting article, but my general problem with these approaches is that they seem to look for one major "reason" evolution produced brains. Even for a less sophisticated internal organs, their functions are multiple (which is what makes medicine more complicated than we'd wish) and for something that's a Turing-complete piece of wetware there is no reason to think less.
The interesting question to me is "do people argue to win arguments?", followed by "which people", "how often", "under which circumstances"? The general jist of "brains evolved for arguing" does little to control my anticipation, though addmittedly it might have been a useful reflection/observation-directing hint to my earlier more naive self.
I saw this in the Facebook "what's popular" box, so it's apparently being heavily read and forwarded. There's nothing earthshattering for long-time LessWrong readers, but it's a bit interesting and not too bad a condensation of the topic:
A glance at the comments [at the Times], however, seems to indicate that most people are misinterpreting this, and at least one person has said flatly that it's the reason his political opponents don't agree with him.
ETA: Oops, I forgot the most import thing. The article is at http://www.nytimes.com/2011/06/15/arts/people-argue-just-to-win-scholars-assert.html