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# Sixty Years on One Hand
- URL: https://davidnunez.com/sixty-years-on-one-hand/
- Published: 2026-09-03T18:13:02.000Z
- Updated: 2026-09-03T18:13:02.000Z
- Description: A doctor cracked the knuckles of one hand for sixty years to test something his mother told him. Nobody else had bothered.
- Author: David Nuñez
- Tags: broadcast

Donald Unger was warned as a child by what he described as ["various renowned authorities (his mother, several aunts and, later, his mother-in-law)"](https://www.scientificamerican.com/article/crack-research/?ref=davidnunez.com) that cracking his knuckles would wreck his fingers.

So like any self-disrespecting biohacker, he decided to run the experiment on himself. For sixty years, he cracked the knuckles of his left hand at least twice a day, something like 36,500 times, and never once cracked the right.

He [published his results](https://pubmed.ncbi.nlm.nih.gov/9588755/?ref=davidnunez.com) as a letter to a rheumatology journal in 1998, reporting no difference between the two hands.

In 2009, at 82, he collected an [Ig Nobel Prize](https://improbable.com/2010/02/15/ig-nobel-acceptance-speech-knuckle-cracking/?ref=davidnunez.com) for it.

He used the acceptance speech to specify the headstone he wants: "Here lies Donald Unger, who has finally quit cracking his knuckles."

[A 2011 study](https://www.jabfm.org/content/24/2/169?ref=davidnunez.com) of 215 people found arthritis in 18.1 percent of the knuckle crackers and 21.5 percent of everyone else, which is to say the knuckle crackers had *less* arthritis than the people who had obeyed.

So the arthritis is a myth. Then a [1990 study of 300 patients](https://pmc.ncbi.nlm.nih.gov/articles/PMC1004074/?ref=davidnunez.com) turned up an effect no mother had ever threatened anyone with. The habitual crackers had more hand swelling and weaker grip. Neither group had extra arthritis.

That is worse than being wrong. For about a century the rule carried a false mechanism and a true effect bolted together, and you could not have pulled them apart, because the people repeating it were not measuring anything.

Which is what a fable does. Red Riding Hood is a warning about getting lost in the woods dressed up as a wolf in a bonnet, and the ridiculous half is what makes it stick. Wrong about the wolf, close enough about the woods.

Parents teach the knuckle cracking rule to essentially every English-speaking child. Few studies have checked it. It's the Big Bad Wolf all over again.

Mothers still tell their children not to do it, and for the record, I'm okay with this because brats cracking their knuckles all day long is just... ew.

Tell someone not to do a thing and they stop doing it, so the evidence arrives late and thin, if it arrives at all. Sometimes the effects are only tangentially related to the warnings. And if they do it anyway and come to no harm, that counts for nothing with anyone, because they were breaking a rule and no one was keeping score.

**Obedience is what protects the rule. A rule with nothing arguing against it looks a great deal like a rule that is true.**

That is not confirmation bias, which at least needs some evidence to misread. This is somewhat more insidious. It is a [self-sealing](https://www.logicallyfallacious.com/logicalfallacies/Self-Sealing-Argument?ref=davidnunez.com) claim, one that no evidence can be brought against no matter what, because obeying it is the thing that stops the evidence from existing.

**A fable about monkeys, bananas, and the corporate ladder.**

![](https://storage.ghost.io/c/2a/66/2a66aa35-855e-4718-a6f9-5e4f6e1dc30d/content/images/2026/09/image.png)

**Köhler's The Mentality of Apes (1925) via (*[**Digital Library of India*](https://archive.org/details/in.ernet.dli.2015.187610/mode/2up) *on archive.org)*

Five monkeys are in a cage. There's a banana in there at the top of a ladder, taunting the prisoners with its delicious fruity flesh. Every time one of the monkeys gives into temptation and tries to climb the ladder, all five monkeys get sprayed with cold water. Monkeys hate getting sprayed with cold water, and let's face it, so would you if you were living in a cage 9-5 every day.

So eventually, whenever one of their more ambitious colleagues attempts to climb the ladder, the other monkeys drag him down.

Then, because scientists derive some kind of enjoyment by creating toxic workspaces for primates, the monkeys are swapped out one at a time, without any discernible explanation and certainly no cushy severance packages, until none of the originals are left.

None of the new "recruits" have ever been sprayed, and yet they still beat up anyone who goes near the ladder.

This story turns up in LinkedIn posts and management consulting decks and podcasts featuring thought leaders. It's almost always described as an experiment that's supposed to be some insight about the rules of office politics.

Except, it's all based on a lie. Or if we're being generous, a lazy reading of the evidence.

The primatologist, Dario Maestripieri, went looking for the actual research and reported back: ["The experiment as described in the story ... never happened."](https://www.psychologytoday.com/us/blog/games-primates-play/201203/what-monkeys-can-teach-us-about-human-behavior-facts-fiction?ref=davidnunez.com)

There *was* a real study. G. R. Stephenson published it in 1967 in [*Progress in Primatology*](https://eurekamag.com/research/024/423/024423546.php?ref=davidnunez.com), and it asked whether one monkey can teach another to be scared of something. He trained rhesus monkeys to leave an object alone by puffing air at them, then put each trained monkey in a cage with one untrained monkey of the same sex.

Two animals. No ladder, no banana, no gang. Just a 1-1 meeting with an air hose.

It half worked. The naive males did back away from the object after coworking with a trained partner, and one trained male [physically pulled his colleague away](https://www.psychologytoday.com/us/blog/games-primates-play/201203/what-monkeys-can-teach-us-about-human-behavior-facts-fiction?ref=davidnunez.com) from it, which is the single detail in the whole legend that ever actually happened, once, to one monkey.

The females did the reverse. Put a trained female in with one who had never been puffed at, and the trained one *lost* her fear, because she watched her cage mate handle the thing and come to no harm.

I'm sure someone will turn *this* variation into a Coaching Framework on LinkedIn, if they haven't already.

The ladder and the banana came from somewhere else: [Wolfgang Köhler's](https://en.wikipedia.org/wiki/Wolfgang%5FK%C3%B6hler?ref=davidnunez.com) [chimpanzees](https://en.wikipedia.org/wiki/Sultan%5F%28chimpanzee%29?ref=davidnunez.com) on Tenerife, who spent the years around the First World War stacking crates to reach fruit hung from a ceiling. 

An [innovation glossary](https://www.humanperf.com/en/blog/nowiunderstand-glossary/articles/5monkeys-experiment?ref=davidnunez.com) has a section headed "Is the monkey theory itself a myth?" It concedes the point, and keeps the story anyway, on the grounds that "whether or not the experiment really took place, this theory clearly shows us the power of conditioning over time."

Does it though? Or does it tell a tidy TED talk story as if it was a rule?

**Sometimes the untested rule is the thing doing the damage.**

![](https://storage.ghost.io/c/2a/66/2a66aa35-855e-4718-a6f9-5e4f6e1dc30d/content/images/2026/09/image-1.png)

**Bamba. The control group ate these.*

If bananas aren't your thing, in 2000 the American Academy of Pediatrics told the parents of high-risk babies to keep peanuts away from them until age three or else they would develop peanut allergies. [In the AAP's own words](https://www.healthychildren.org/English/health-issues/conditions/allergies-asthma/Pages/Peanut-Allergies-What-You-Should-Know-About-the-Latest-Research.aspx?ref=davidnunez.com), "that didn't help, which is why in 2008 the AAP stopped recommending it."

A snack cracked it open. [Gideon Lack](https://www.londonallergy.com/gideon-lack?ref=davidnunez.com), visiting Israel, noticed that pediatricians there barely saw peanut allergy, and that Israeli babies get weaned on [Bamba](https://www.foodpolitics.com/2016/06/israels-solution-to-peanut-allergies/?ref=davidnunez.com), a peanut puff soft enough for a child with no teeth. Jewish children in Britain turned out to have [roughly ten times](https://medreview.odus.princeton.edu/2025/06/23/bamba-babies-how-one-snack-revolutionized-global-understanding-of-peanut-allergies?ref=davidnunez.com) the rate of allergies as their counterparts in Israel. The trial that followed found that feeding peanut to high-risk infants cut their allergy rate at five by [more than 80 percent](https://pmc.ncbi.nlm.nih.gov/articles/PMC4685572/?ref=davidnunez.com).

Fifteen years of a rule doing the opposite of its job. Nobody involved was being careless. The advice itself made the experiment look unnecessary. You do not run a trial to check whether the dangerous thing is dangerous.

**What to do about the fence.**

The ladder. The peanut bans. They must be there for a reason, right? Who are we to dismantle the status quo without knowing the full context? Don't rock the boat and stay in your lane because you don't know what you don't know. This kind of thinking makes [organizational mavericks](https://knowledge.wharton.upenn.edu/article/effective-mavericks-in-business/?ref=davidnunez.com) go bananas. (ahem)

Understand the box before you think outside of it. What do you do if the box is artificial or just plain wrong?

Everybody quotes [G.K. Chesterton](https://en.wikipedia.org/wiki/G.%5FK.%5FChesterton?ref=davidnunez.com) on this. "Don't ever take a fence down until you know the reason why it was put up." He never wrote that sentence, but it is the one that gets passed around, and it sounds like an argument for leaving things alone. [The actual passage](https://www.chesterton.org/taking-a-fence-down/?ref=davidnunez.com), from a 1929 book called *The Thing*, is an instruction that asks for a little more effort:

> "If you don't see the use of it, I certainly won't let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it."

Chesterton also said, in a [1922 newspaper column](https://libquotes.com/g-k-chesterton/quote/lbd5d1z?ref=davidnunez.com), "The reformer is always right about what is wrong. He is generally wrong about what is right."

He is telling you to go and find out why the rules exist. Hardly anybody does that second half, because "that's the way it is" already works as the easy excuse not to bother. It's also how organizations squash anything risky and suck the soul out of orthogonal thinkers.

![](https://storage.ghost.io/c/2a/66/2a66aa35-855e-4718-a6f9-5e4f6e1dc30d/content/images/2026/09/image-2.png)

"Go away and think." - GK Chesterton (via [Wikipedia](https://en.wikipedia.org/wiki/G.%5FK.%5FChesterton?ref=davidnunez.com))

So pick one. Not a belief, a prohibition. Something you were told not to do, by somebody you trusted, that you have never tested and never watched anyone else test. It's something you know in your heart could be done differently if someone just tried it. Everyone is carrying at least three or four of these.

Then work out what it would cost to try something else. Not the worst you can imagine, which is too easy to generate and usually wrong in both directions. What is the actual cost, in hours or dollars or dignity. Scope appropriately. The only thing that settles it is the attempt.

[I watched this unfold recently](https://lnkd.in/p/gJGP8nzZ?ref=davidnunez.com) with a file I keep of things my AI agent team cannot do. It was the kind of list anyone accumulates after enough arguing with a computer. One entry said a particular thing was impossible and had to be done by hand. It cost me a few minutes each day in admin data entry. 

It had been sitting there as settled fact for months. When I went back to see where it came from, it turned out to have been written up from three attempts, two of which had reported success while doing nothing at all, and a third that was never a failure in the first place. I never bothered to challenge why the rule existed and that cost me a micro-annoyance every day.

Micro-annoyances turn into macro-frustrations turn into burning your laptop to the ground. Now imagine that at the scale of an organization trying to replace all of its processes (and people) with AI everywhere.

The more persistent the agents get, with their ever-increasing complexity and reams of generated language instantly decaying, the less likely anyone goes back and retests any of it. The rules accrue faster than they can be checked and strangle innovation in organizations.

We never correct the wrong notes. Instead, we amplify them through attrition.

A list of things that cannot be done is the least tested document in any system, because its entries are the only ones nobody ever attempts again.

Go away and think.

/ David

**Listening:** ["Knock on Wood"](https://www.youtube.com/watch?v=NiMLiAOWoFw&ref=davidnunez.com), Eddie Floyd, Stax, 1966\. A rule, or a superstition nobody has ever tested.