Ever since I was a kid, I’ve cracked my knuckles. I don’t want to do it, but it’s compulsive – the release of the pressure pent up in my fingers. And so, despite years of resolutions, promises to myself and systems of reward and punishment, I continue. I know that eventually I will end up with terrible arthritis.


But wait – it turns out I won’t. Just the other day I discovered that a doctor in 2009 won the IgNobel Prize for Medicine for doing the research that broke the long-held link between knuckle-cracking and arthritis. He cracked the knuckles on one hand for 60 years, to find out if he would develop arthritis (he didn’t).

The IgNobel Prizes are awarded annually for extraordinary research achievements in science that make us laugh, and then think. It worked for me, because this finding about knuckle-cracking has sent me down a rabbit hole of medical folk wisdom. And that hole is dark.

A paper published in Nature in 2019 investigated folk medicine in the US, and the researchers included the link between knuckle-cracking and arthritis as 1 of 11 theories. It was nestled among other things I thought until that moment were true: fizzy drinks can help stomach aches; taking vitamin C can prevent illness; cold weather causes colds.

The good news is I am not any more or less ignorant than their average respondent. But this is still a kind of misinformation. It is inconsistent with medical evidence. It’s enough to make your knuckles crack.

Like other misinformation, this apparently innocuous medical folk wisdom taps into what the researchers describe as an “expert discounting hypothesis” – the belief that I know better than medical science. I, like other people who believe that chicken soup can cure a cold, are victims of a cognitive bias called the Dunning-Kruger effect – an effect where people with only a small amount of knowledge overestimate their expertise.

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Illustration of folk medicine
© Scott Balmer

It doesn’t take an IgNobel Prize to see that discounting medical science in favour of an unconfirmed ‘truism’ can shape health behaviours and attitudes to policy. And this is what the researchers found: people who believe in medical folk wisdom, even the innocuous kind, value medical expertise less.

Take this to the next level, and medical folk wisdom has created a marketplace in anti-science ideas. Other research has found correlations between Dunning-Kruger overconfidence and anti-vaccine attitudes, mask-wearing advice and climate change conspiracies.

When this kind of knowledge was passed around by a matriarch, it didn’t pose nearly as much threat to society as the professionally organised mass media folk wisdom machine. The internet has taken over the role of the village elder, dispensing easy-to-share, not-quite-right information written in Pinterest-friendly fonts to ever-insular echo chambers. Dunning-Kruger-infected collective action is causing harm to public health.

I told you that rabbit hole was dark. But that’s why folklorists and anthropologists look at what wisdom we’re sharing. Because while it might not be true, it does tell us a lot about what we think is.

Read more from Aleks Krotoski:



Social psychologist, broadcaster and journalist. She writes and broadcasts about technology and interactivity, and she presents Digital Human on BBC Radio 4. She is the author of Untangling the Web: What the Internet is Doing to You.