It's called the argumentative theory of reasoning, and it says that humans didn't learn to ask questions and offer answers in order to find universal truths. We did it as a way to gain authority over others. That's right -- they think that reason itself evolved to help us bully people into getting what we want. Here's how a proponent puts it:
"'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."
And as evidence, the researchers point out that after thousands of years of humans sitting around campfires and arguing about issues, these glaring flaws in our logic still exist.
Apparently, being dominant is more adaptive for evolutionary purposes than being open-minded. Link -via Buzzfeed
You could make the argument that the "goal" in social interaction is to win the argument, but reasoning didn't come about specifically to fulfill that goal, it just is used for that purpose.
And because I've been correcting for my own personal bias while writing this, I'll note that they could be referring to "reasoning" as specifically the act of verbally communicating with someone (as opposed to the more abstract concept of "figuring something out"). I would agree then that its true, but only to the extent that you're dealing with someone whose goal is to convince the other person of something. That's probably a default action, but not a unavoidable one.
;) and :(