One of the most obvious truths about the modern world is that a whole lot of people believe a whole lot of nonsense – about climate change not being real, Brexit being a sensible idea, gun ownership helping reduce crime, and so on. By contrast, one of the hardest truths to accept is that you – you, of all people! – are just as susceptible, in principle, to the very same mistake.

That’s the gist of years of research into “motivated reasoning”: across the political spectrum, we use reason not simply to get at the facts, but for all sorts of ulterior motives, such as persuading others of our opinions, feeling a sense of belonging to our tribe, or reducing the sense of mismatch between our beliefs and reality. Ironically, therefore, the idea that only those idiots on the other side are guilty of motivated reasoning is itself a case of motivated reasoning. To imagine oneself immune to fake news is fake news – at least according to studies like the one that found leavers and remainers are equally likely to believe false stories that bolstered their views.

One of the sneakier forms of the problem, highlighted in a recent essay by the American ethicist Jennifer Zamzow, is “solution aversion”: people judge the seriousness of a social problem, it’s been found, partly based on how appetising or displeasing they find the proposed solution. Obviously, that’s illogical: the fact that you might hate paying more tax to keep the NHS afloat has no bearing on whether or not the NHS is in crisis. But that’s how people reason: show Americans who support gun control an article suggesting that looser gun laws would help deter violent burglaries, and they’ll judge violent burglary less of a problem than if they’re told tighter laws are the answer. Tell someone who opposes government regulations that they’re the only solution to climate change, and he’s more likely to reject the idea that it’s a serious issue to begin with. And the point isn’t just that people say these things, so as not to make their prejudices look silly. It’s that they’re genuinely less likely to believe that problems requiring unpalatable solutions are problems at all.

Switch the focus to personal matters, and it’s clear that solution aversion is another manifestation of our old Freudian friend, denial. You’ll be strongly motivated to deny problems in your relationship if you dread the loneliness of singlehood; or the fact that your work feels meaningless if your dominant fear is financial insecurity. Who couldn’t empathise with that kind of urge to deny what’s too scary to face? Which is why, to turn back to politics, motivated reasoning ultimately offers grounds for hope. After all, if the other side’s refusal to engage with the facts is explained by sheer stupidity, or by evil, there’s no way forward. On the other hand, if it’s the unfortunate result of an eminently relatable response to feeling afraid, at least there’s a shared starting point from which we might reach more understanding.

If we can’t agree on the facts, these days, at least we can agree that it’s almost universally difficult to face them.

oliver.burkeman@theguardian.com

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Julia Galef, an expert on human judgment, talks about “how to argue better and change your mind more” in an episode of the Ezra Klein Show podcast