By John Ehrenreich/ Slate/ November 9, 2017

Many conservatives have a loose relationship with facts. The right-wing denial of what most people think of as accepted reality starts with political issues: As recently as 2016, 45 percent of Republicans still believed that the Affordable Care Act included “death panels” (it doesn’t). A 2015 poll found that 54 percent of GOP primary voters believed then-President Obama to be a Muslim (…he isn’t).

And then it gets really crazy. Almost 1 in 6 Trump voters, while simultaneously viewing photographs of the crowds at the 2016 inauguration of Donald Trump and at the 2012 inauguration of Barack Obama , insisted that the former were larger. Sixty-six percent of self-described “very conservative” Americans seriously believe that “Muslims are covertly implementing Sharia law in American courts.” Forty-six percent of Trump voters polled just after the 2016 election either thought that Hillary Clinton was connected to a child sex trafficking ring run out of the basement of a pizzeria in Washington, D.C., or weren’t sure if it was true.

If “truth” is judged on the basis of Enlightenment ideas of reason and more or less objective “evidence,” many of the substantive positions common on the right seem to border on delusional. The left is certainly not immune to credulity (most commonly about the safety of vaccines, GMO foods, and fracking), but the right seems to specialize in it. “Misinformation is currently predominantly a pathology of the right,” concluded a team of scholars from the Harvard Kennedy School and Northeastern University at a February 2017 conference. A BuzzFeed analysis found that three main hyperconservative Facebook pages were roughly twice as likely as three leading ultraliberal Facebook pages to publish fake or misleading information.

Why are conservatives so susceptible to misinformation? The right wing’s disregard for facts and reasoning is not a matter of stupidity or lack of education. College-educated Republicans are actually more likely than less-educated Republicans to have believed that Barack Obama was a Muslim and that “death panels” were part of the ACA. And for political conservatives, but not for liberals, greater knowledge of science and math is associated with a greater likelihood of dismissing what almost all scientists believe about the human causation of global warming.

Part of the problem is widespread suspicion of facts—any facts. Both mistrust of scientists and other “experts” and mistrust of the mass media that reports what scientists and experts believe have increased among conservatives (but not among liberals) since the early ’80s. The mistrust has in part, at least, been deliberately inculcated. The fossil fuel industry publicizes studies to confuse the climate change debate; Big Pharma hides unfavorable information on drug safety and efficacy; and many schools in conservative areas teach students that evolution is “just a theory.” The public is understandably confused about both the findings and methods of science. “Fake news” deliberately created for political or economic gain and Donald Trump’s claims that media sites that disagree with him are “fake news” add to the mistrust.

But, the gullibility of many on the right seems to have deeper roots even than this. That may be because at the most basic level, conservatives and liberals seem to hold different beliefs about what constitutes “truth.” Finding facts and pursuing evidence and trusting science is part of liberal ideology itself. For many conservatives, faith and intuition and trust in revealed truth appear as equally valid sources of truth.

To understand how these differences manifest and what we might do about them, it helps to understand how all humans reason and rationalize: In other words, let’s take a detour into psychology. Freud distinguished between“errors” on the one hand, “illusions” and “delusions” on the other. Errors, he argued, simply reflect lack of knowledge or poor logic; Aristotle’s belief that vermin form out of dung was an error. But illusions and delusions are based on conscious or unconscious wishes; Columbus’s belief that he had found a new route to the Indies was a delusion based on his wish that he had done so.

Although Freud is out of favor with many contemporary psychologists, modern cognitive psychology suggests that he was on the right track. The tenacity of many of the right’s beliefs in the face of evidence, rational arguments, and common sense suggest that these beliefs are not merely alternate interpretations of facts but are instead illusions rooted in unconscious wishes.

Our reasoning is also influenced(motivated, psychologists would say) by our emotions and instincts. This manifests in all kinds of ways: We need to maintain a positive self-image, to stave off anxiety and guilt, and to preserve social relationships. We also seek to maintain consistency in our beliefs, meaning that when people simultaneously hold two or more contradictory beliefs, ideas, or values, one or the other must go. And so we pay more attention and give more credence to information and assertions that confirm what we already believe: Liberals enthusiastically recount even the most tenuous circumstantial evidence of Trump campaign collusion with the Russians, and dyed-in-the-wool Trump supporters happily believe that the crowd really was bigger at his candidate’s inauguration.