It sounds profound, but is it wise words, or just bollocks?
Here, at least is the latest in the 'evolution was just like this' department. A study on reasoning that is part of an issue on the subject in the Journal of Behavioral and Brain Sciences, concludes that reasoning evolved to be deceiving rather than to tell the truth. At least, the authors of this new just-so story don't claim it's genetic: deceptive rhetoric evolved socially.
As the NYTimes reports, it has long been assumed that reasoning evolved to enable us to search for and determine Truth. But,
[n]ow 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.Now whether this is true in all societies, a uniform cultural evolution or a parallel one (similar in, say Pacific Islanders and African Ashanti or San, but of independent social-evolutionary origin) is a valid question. In fact, much as we hate to take sides with the genetic-evolutionary view (!), there have been numerous arguments that human language is basically an extension of eons-old display tactics that were designed to intimidate or deceive, as in mating competition. Such things are not new to humans, or even primates, so if it is biological it predates our species and the explanation is more general.
However, let's ignore whether it's cultural or biological. The same people who fervidly see competition-everywhere, the arch-darwinian view of life, will love the idea that she dissembles to deceive. If you're looking for a rival under every bed, you'll certainly go along with the idea that we use language (reasoning, persuasion, rhetoric) to distract, derail, or deceive potential competitors: you really do, as the article says, want to win rather than to inform others.
This certainly is one way language is used (at least in cultures in nation-states, where we have daily evidence). But is it 'the' truth? Is it part of culture, or only of some cultures....or did cultures evolve reasoning 'for' deception per se?
It is easy to see a polar opposite to the latest assault of selectionism. If you deceive, you can cause others to come to loss or grief. Why should they not have a long memory, that they'll use to even the score later? Why isn't truth good for the group, and deception a way to make everyone vulnerable? Our ancestors--including primates--lived in very small local groups. They might be very vulnerable to internal misinformation. Why is telling the truth institutionalized in many if not most cultural norms--what children are taught, for example, even if we're not perfect at it? Is that because if everyone is convinced you're truth-telling, it's easier for you to mislead? Or is it because truth-telling really is what's important, and you mutually have to rely on it for your survival?
Further, what is truth and how do you know what people's motives are (whether they are even aware of them or not)? Since 'truth' is what we think we perceive, and since we always have imperfect data, imperfect perception, and imperfect intelligence, why should we assume that 'reasoning' is false rather than flawed? After all, even 'experts' in most fields related to behavior (to wit: economists, pundits) are grossly wrong presumably because of ignorance or bias rather than intentional deception. One might suggest that the journal article's authors' interpretation of the intent in reasoning is more a reflection of their ideologies and biases, than it is of the underlying truth (or are we just saying that to make you believe us??).
Anyway, why should our ability to reason have evolved for only one purpose? Did our hands evolve just to let us hunt? Like most traits, reason is multi-purpose, and can be as useful for cooperation as well as competition -- and many other things. It's how we express how we assess our environment, our circumstances. Often it is verbal expression, imperfectly representing our internal thoughts. We can reason our way to figuring out from these footprints what kind of prey we're likely to find if we hang out long enough at the waterhole, or that that plant is poisonous, or to formulating a mathematical proof just as we can clap with our hands, help another across a creek, and caress a child's cheek. And, it's not just that the functions other than winning arguments are exaptations (purposes beyond the one the trait first evolved 'for') of the ability to reason, because ants and bees can reason. Or is deceptive reasoning limited, by social constraints, to certain but not all topics of conversation?
The choice of a single overriding purpose for our ability to reason says more about the those doing the choosing than it does about the trait.