Humans like to think of themselves as rational, reasoning beings. We are certainly capable of being rational, but so much of our reasoning seems to be directed at rationalization -- using reason to defend and justify ideas that aren't true, but which we wish to be true. But why? Perhaps because we like to argue and persuade so much, no matter what the subject or idea.
Photo: Vincent Besnault/Getty
Other primates aren't like this and the key difference seems to be the development of language. There are a lot of benefits to language, but also dangers: it's easier to lie. So how do you decide whom to trust and when? Well, that presents a whole new list of challenges -- part of the challenges that are inherent in complex social lives.
And how do we deal with problems when our own brains lead us to rationalize? The answer seems to be to avoid relying solely on ourselves and instead engage in collective reasoning. Multiple people working together rather than against each other can overcome the flaws in any single person's reasoning.
Hugo Mercier at the University of Neuchâtel, Switzerland, and Dan Sperber at the Central European University in Budapest, Hungary, believe that human reasoning evolved to help us to argue. An ability to argue convincingly would have been in our ancestors' interest as they evolved more advanced forms of communication, the researchers propose.
Since the most persuasive lines of reasoning are not always the most logical, our brains' apparent foibles may result from this need to justify our actions and convince others to see our point of view - whether it is right or wrong. "You end up making decisions that look rational, rather than making genuinely rational decisions," says Mercier.
The flip side, of course, is that we also face the risk of being duped by others, so we developed a healthy scepticism and an ability to see the flaws in others' reasoning. This ability to argue back and forth may have been crucial to humanity's success - allowing us to come to extraordinary solutions as a group that we could never reach alone. ...
...experiments have shown that people are more susceptible to the bias when they are told that they will have to defend their decision, just as you would expect if we evolved to convince others of our actions (Journal of Behavioral Decision Making, vol 20, p 125). The effect may weigh heavily on the way we weigh up the benefits and risks of certain lifestyle choices - it is the reason that "90 per cent fat-free" food sounds healthy, when a product advertised with "10 per cent fat content" would seem less attractive.
Drawing together all the difference strands of evidence, Mercier and Sperber published a paper in Behavioral and Brain Sciences journal last year outlining their theory (vol 34, p 57). In addition to confirmation bias and the framing and attraction effects, they cited many other seemingly irrational biases that might be explained by our argumentative past, including the sunk-cost fallacy - our reluctance to cut our losses and abandon a project even when it would be more rational to move on - and feature creep, which includes our tendency to buy goods with more features than we would ever actually use.
Source: New Scientist, October 13, 2012
Of course, collective reasoning and deliberation is no guarantee of arriving at truth. It, too, can go astray -- but it's far more likely to get good results than not. It's how science proceeds and look at how far the scientific method has come in just the past couple of hundred years as compared to the past few centuries and millennia of human civilization.
What we need is to find more ways to engage the benefits of collective reasoning as it functions within science. However imperfect it may be, it still overcomes the greater imperfections we have as individuals acting alone.