Philosophers rightly think of themselves as experts on reasoning. After all, it was a philosopher, Aristotle, who developed the science of logic. But psychologists have also had some interesting things to say about the subject. A fascinating paper by Dan Sperber and Hugo Mercier has recently generated a lot of discussion.
The headline of an article in The Times about the paper— echoed on blogs and other sites — was, “Reason Seen More as Weapon than Path to Truth, ” a description, that implied that reason is not, as we generally think, directed to attaining truth, but rather to winning arguments. Many readers of the Times article thought that this position amounted to a self-destructive denial of truth. The article itself (though perhaps not the abstract) suggests a more nuanced view, as the authors tried to explain in replies to criticism. In any case, we can develop an interesting view of the relation between argument and truth by starting from the popular reading and criticism of the article.
Sperber and Mercier begin from well-established facts about our deep-rooted tendencies to make mistakes in our reasoning. We have a very hard time sticking to rules of deductive logic, and we constantly make basic errors in statistical reasoning. Most importantly, we are strongly inclined to “confirmation-bias”: we systematically focus on data that support a view we hold and ignore data that count against it.
These facts suggest that our evolutionary development has not done an especially good job of making us competent reasoners. Sperber and Mercier, however, point out that this is true only if the point of reasoning is to draw true conclusions. Fallacious reasoning, especially reasoning that focuses on what supports our views and ignores what counts against them, is very effective for the purpose of winning arguments with other people. So, they suggest, it makes sense to think that the evolutionary point of human reasoning is to win arguments, not to reach the truth.
http://opinionator.blogs.nytimes.com/2011/06/29/argument-truth-and-the-social-side-of-reasoning/?ref=opinion