According to the research described in this Boston Globe article,

Facts don’t necessarily have the power to change our minds. In fact, quite the opposite. In a series of studies in 2005 and 2006, researchers at the University of Michigan found that when misinformed people, particularly political partisans, were exposed to corrected facts in news stories, they rarely changed their minds. In fact, they often became even more strongly set in their beliefs. Facts, they found, were not curing misinformation. Like an underpowered antibiotic, facts could actually make misinformation even stronger.

This bodes ill for a democracy, because most voters — the people making decisions about how the country runs — aren’t blank slates. They already have beliefs, and a set of facts lodged in their minds. The problem is that sometimes the things they think they know are objectively, provably false. And in the presence of the correct information, such people react very, very differently than the merely uninformed. Instead of changing their minds to reflect the correct information, they can entrench themselves even deeper.

“The general idea is that it’s absolutely threatening to admit you’re wrong,” says political scientist Brendan Nyhan, the lead researcher on the Michigan study. The phenomenon — known as “backfire” — is “a natural defense mechanism to avoid that cognitive dissonance.”

I’ve been aware of this phenomenon for a while now, but have not found an existing label or definition. So, prompted by this article, I shall henceforth refer to this as the backfire bias: the tendency to entrench our opinions even deeper when confronted with countering evidence and arguments, rather than admit we are wrong. I have seen people who are prone to this bias, and it is sad to behold — all the more so because the very built-in coping mechanisms that cause the backfire bias (rationalization and revisionist memory, for example) make people blind to the very fact they are doing it. It is all but impossible to convince such a person that he/she has a problem.

And it is related to what I’ve informally thought of as the “I just know” bias: the tendency of people to cling to opinions without any evidence- or logic-based justification, because they “just know” that they are right.

…

Studies by other researchers have observed similar phenomena when addressing education, health care reform, immigration, affirmative action, gun control, and other issues that tend to attract strong partisan opinion. Kuklinski calls this sort of response the “I know I’m right” syndrome, and considers it a “potentially formidable problem” in a democratic system. “It implies not only that most people will resist correcting their factual beliefs,” he wrote, “but also that the very people who most need to correct them will be least likely to do so.”

…

Our brains are designed to create cognitive shortcuts — inference, intuition, and so forth — to avoid precisely that sort of discomfort while coping with the rush of information we receive on a daily basis. Without those shortcuts, few things would ever get done. Unfortunately, with them, we’re easily suckered by political falsehoods.

HT to Rationally Speaking.