skepticblog | Hearing the speakers at the GOP convention spout their ideas this week, I’m again reminded that an entire American political party is proudly and openly espousing views that are demonstrably contrary to reality, from claiming that rape does not cause pregnancy, to claiming that global climate change is a hoax, to even weirder idea, like the bizarre notion that the President of the United States is a Kenyan Muslim. For years, I’ve puzzled over why people can believe such weird things as creationism or other kinds of pseudoscience and science denials. In my 2007 book Evolution: What the Fossils Say and Why it Matters, I devoted an entire chapter to asking why creationists can so confidently believe patently false ideas, and refuse to look at any evidence placed in front of them. I’ve compared it to Alice’s Adventures Through the Looking Glass, where Alice steps through the mirror and finds that the objects and the landscape look vaguely familiar—but all the rules of logic are reversed or turned inside out. How can people continue to believe things that are clearly wrong, and refuse to change their ideas or look at evidence?
It turns out that human brains are constructed very differently than what we would like to believe. As described by Chris Mooney (2012) in The Republican Brain: The Science of Why they Deny Science—and Reality, our brains are not logical computers or non-emotional Vulcans like Dr. Spock, but organs in emotional animals who navigate the factual world to fit our beliefs and biases. Mooney explains this by starting with an anecdote about the Marquis de Condorcet, an important figure in the French Enlightenment (he helped develop both integral calculus and also wrote many important works on politics and philosophy). Condorcet believed in the Enlightenment ideal that humans would always be rational and guided by reason, and persuaded if logic and evidence were considered—and lost his life in 1794 during the irrational, emotional, highly political Reign of Terror. Even though Enlightenment philosophy and political science long argued that humans are rational animals, modern psychology and neurobiology have shown this is not the case. Humans filter the world to see what fits their emotional and cultural biases, and easily neglect evidence and information that does not fit (confirmation bias). Even more to the point, we are prone to what psychologists now call motivated reasoning—confirmation bias, reduction of cognitive dissonance, shifting the goalposts, ad hoc rationalization to salvage falsified beliefs, plus other mental tricks cause us to constantly filter the world. Our minds do not behave by objectively weighing all the evidence and listening to reason, but instead acts as if we were lawyers seeking evidence to bolster our pre-existing beliefs. Instead of the Enlightenment ideal that humans would change their minds when the facts go against them, motivated reasoning explains why humans are adept at bending or ignoring facts to fit the world as we want to see it.