Skip to content

Why Does Confirmation Bias Exist?

My colleague Don Taylor, who blogs over at the Incidental Economist, had an interesting post today about an article by Johah Lehrer in Wired discussing the reason behind the existence of confirmation bias:

“The larger question, of course, is why confirmation bias exists. This is the sort of mental mistake that seems ripe for fixing by natural selection, since it always leads to erroneous beliefs and faulty causal theories. We’d be a hell of a lot smarter if we weren’t only drawn to evidence that confirms what we already believe.

And this leads me to a fascinating and provocative new theory of reasoning put forth by Hugo Mercier and Dan Sperber. In essence, they argue that human reason has nothing to do with finding the truth, or locating the best alternative. Instead, it’s all about being able to argue with others:

‘Reasoning is generally seen as a mean to improve knowledge and make better decisions. Much evidence, however, shows that reasoning often leads to epistemic distortions and poor decisions. This suggests rethinking the function of reasoning. Our hypothesis is that the function of reasoning is argumentative. It is to devise and evaluate arguments intended to persuade.'”