By PATRICIA COHEN
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. Rationality, by this yardstick (and irrationality too, but we'll get to that) is nothing more or less than a servant of the hard-wired compulsion to triumph in the debating arena. According to this view, bias, lack of logic and other supposed flaws that pollute the stream of reason are instead social adaptations that enable one group to persuade (and defeat) another. Certitude works, however sharply it may depart from the truth.
The idea, labeled the argumentative theory of reasoning, is the brainchild of French cognitive social scientists, and it has stirred excited discussion (and appalled dissent) among philosophers, political scientists, educators and psychologists, some of whom say it offers profound insight into the way people think and behave. The Journal of Behavioral and Brain Sciences devoted its April issue to debates over the theory, with participants challenging everything from the definition of reason to the origins of verbal communication.
"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.
Indeed, Mr. Sperber, a member of the Jean-Nicod research institute in Paris, first developed a version of the theory in 2000 to explain why evolution did not make the manifold flaws in reasoning go the way of the prehensile tail and the four-legged stride. Looking at a large body of psychological research, Mr. Sperber wanted to figure out why people persisted in picking out evidence that supported their views and ignored the rest - what is known as confirmation bias - leading them to hold on to a belief doggedly in the face of overwhelming contrary evidence.
Other scholars have previously argued that reasoning and irrationality are both products of evolution. But they usually assume that the purpose of reasoning is to help an individual arrive at the truth, and that irrationality is a kink in that process, a sort of mental myopia. Gary F. Marcus, for example, a psychology professor at New York University and the author of "Kluge: The Haphazard Construction of the Human Mind," says distortions in reasoning are unintended side effects of blind evolution. They are a result of the way that the brain, a Rube Goldberg mental contraption, processes memory. People are more likely to remember items they are familiar with, like their own beliefs, rather than those of others.
What is revolutionary about argumentative theory is that it presumes that since reason has a different purpose - to win over an opposing group - flawed reasoning is an adaptation in itself, useful for bolstering debating skills.
Mr. Mercier, a post-doctoral fellow at the University of Pennsylvania, contends that attempts to rid people of biases have failed because reasoning does exactly what it is supposed to do: help win an argument.
"People have been trying to reform something that works perfectly well," he said, "as if they had decided that hands were made for walking and that everybody should be taught that."Imagine a prehistoric hunting party arguing over how best to approach the deer they've spotted. The deer isn't going to be influenced by the charisma of their arguments, so they have an incentive to come up with the best decision because they are hungry. On the other hand, the various participants also have their own special interests, short term (e.g., I want a strategy where I make the kill because I'll get a bigger slice or I want a lower risk strategy because I'm not that hungry) and long term (I want to win the argument because I want to build a reputation as a smart decision maker so I'll have political capital). But keep in mind that arguing consumes times, energy, and scares away the deer. It's often better to minimize the number of decisionmakers in a tactical situation. So, it makes more sense to argue for fun in the evening, to spar for dominance verbally by demonstrating a quick wit in oral combat or explain a complicated plan when there's time for others to listen. And everybody has an incentive to listen in to figure out whose likely to make good decisions on the spot in the morning with life or death in the balance. You need to know who to trust.
On the other hand, making good decisions about how to catch deer is hard, so ambitious men have incentives to use arguments that philosophers would consider not cricket to persuade other men to follow them. And even if those arguments aren't objectively better at catching deer in isolation, they might be subjectively better at unifying the team, and thus, in the bigger picture, be objectively better at catching deer. All this is pretty inevitable. What I think is bizarre is that the Ancient Greeks started treating argument not just as a sport, but as one with objective fair play rules for deciding who wins. Consider Zeno's Paradoxes that were brought to Athens by Parmenides and Zeno when Socrates was a young man: the arrow can't reach the target because it first must go 1/2 the distance, then 1/4 the distance, etc. I think in most times and places, Zeno would have eventually got himself punched in the face. But the Greeks thought it was important to figure out why he was wrong.