The Evolution of Stupidity (and Octopus Intelligence)
What we can learn about intelligence, stupidity, and ourselves—from some of the smartest, strangest, alien-like creatures on the planet.
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I: “But I wore the juice”
At 2:47pm on January 6, 1995, Clifton Johnson and McArthur Wheeler walked into the Mellon Bank branch in Swissvale, a small suburb of Pittsburgh. One of them pointed a handgun at the teller, demanding cash. The teller, shaking with fear, handed over some money. The robbers ran out.
Unlike most bank robbers, Johnson and Wheeler made no attempt to disguise themselves, nor to obscure their faces with masks. They looked straight into security cameras. This was particularly puzzling because Wheeler, five foot six and 270 pounds, had an easily identifiable physique—and a distinct face. Sure enough, his conspicuousness doomed him. The local news flashed a photo of Wheeler on the 11 o’clock news. An hour later, after tip-offs flooded in, Wheeler was arrested.
“But I wore the lemon juice. I wore the lemon juice,” Wheeler protested as he was taken into custody. When the cops showed him surveillance footage in which he’s clearly visible robbing the bank, Wheeler’s face contorted in disbelief. Something in his ingenious plan, he realized, had gone very wrong.
Somehow—perhaps due to its relation with disappearing ink—Wheeler believed that lemon juice could make human faces invisible to security cameras. So, even though it made his eyes sting, Wheeler slathered on the juice.
But Wheeler was no sheep-like simpleton. He wisely tested the efficacy of the juice before the robbery. He squirted it on his face, then attempted to take a photo of himself with a Polaroid camera. When the image came out, Wheeler was astonished: he wasn’t in the shot. Convinced by his rigorous scientific experiment, he proceeded to rob the bank, protected by the magic juice. (It’s likely Wheeler pointed the Polaroid camera in the wrong direction and just didn’t realize it).1
This story, which inspired the research into what we now know as the Dunning-Kruger Effect, is a testament to the extraordinary power of human stupidity.
Sadly, so much of our discourse around intelligence and stupidity gets hijacked by pseudoscience, racism, and debates over whether arbitrary measurements like IQ are valid. We ignore more interesting questions around intelligence and stupidity that we can learn not from ourselves, but from other species. In particular:
What, specifically, does it mean to be “intelligent?” What do we mean when we say that humans and chimps and dolphins and crows are intelligent?
Why did some species—including us—become smart, while others didn’t?
Why is stupidity still so widespread in humans?
Pondering these questions requires going on a bit of a wild ride, exploring fascinating animal worlds from chimpanzees to cephalopods, as we begin to understand our own cleverness—and stupidity—through the eyes of an octopus, the closest thing to alien intelligence on Earth.2
II: Chimpanzees, Rubik’s cubes, and disappearing ink
“It’s quite common for people [scientists] to talk about intelligence. It’s less common for people to talk about stupidity, though, arguably, it’s more common.” So observes David Krakauer, evolutionary biologist, genius polymath, and president of the world hub of complex systems research, the Santa Fe Institute.
Krakauer has devoted himself to the study of stupidity. In the process, he has made a series of illuminating arguments about how to consider cross-species intelligence, since IQ tests aren’t an effective tool to determine whether an elephant is smarter than a crow.
Krakauer points out that humans and chimpanzees share nearly 99 percent of our genetic code. “Imagine I gave you Hamlet,” Krakauer says, “and I changed less than 1 percent of the text and I said, ‘What’s the play?’ and you said, ‘It’s Hamlet.’ And I said, ‘What have I changed?’ ‘I’m not quite sure…I did see a few typos.’”
Like a few typos in Hamlet, we are divided from chimps by tiny, almost imperceptible variations. So, how can there be this massive chasm in behavioral intelligence and complexity between chimps and humans with such small divergences in genetics? It’s an enduring puzzle; we still don’t have the answers.
But Krakauer distances himself from what he sees as unhelpful debates around IQ and instead focuses on more general ideas around intelligence, ignorance, and stupidity. His definitions have the advantage of applying across diverse species.
Ignorance is a lack of relevant data; you don’t have the information necessary to solve a problem. It’s about a gap of information, not limited cognition.
Intelligence is when one can derive simple solutions to complex problems—and make it look effortless. With intelligence, more relevant information helps you solve a problem faster. Intelligence means you will solve a problem at a rate significantly faster than by trying solutions at random.
Stupidity is when you use a rule, or a system of thought, in which adding more data or information doesn’t make it any more likely that you’ll get the correct answer. In the extremes of stupidity, one would solve a problem more slowly than if that creature just tried solutions derived from random chance.
To illustrate these points more precisely, Krakauer draws on the example of a Rubik’s cube. There are 43 quintillion possible arrangements of the cube. If you were immortal and randomly moved bits of the cube, eventually, you’d solve it—but it would take a ridiculously long time—billions upon billions of years.
A stupid solution would be to simply keep rotating the same face, over and over, even if someone came along and gave you instructions on how to solve it. With that stubbornly stupid strategy, you’d never solve the puzzle.
The intelligent solution lies at the other extreme: the Rubik’s cube world record currently stands at 3.13 seconds, set in July 2023.
However, the record-holder, 23 year-old Max Park, didn’t discover the insights that allowed him to solve the Rubik’s cube. His success was built atop a foundation of accumulated knowledge that mathematicians and puzzle enthusiasts derived—mental algorithms that enable “cubers” to solve the puzzle with lightning speed.
Collectively, humans have produced an extremely intelligent solution to a complex problem—and it’s trillions of times faster than trying random solutions.
This is one of the unique tricks that has allowed humans to collectively become the world’s smartest species. Krakauer refers to this secret weapon as exbodiment, the transfer of knowledge from our brains to external repositories and tools, which can be shared, iteratively improved, and transferred across space and time.
“Most of what happens cognitively doesn’t happen in here [our brains], but out there,” Krakauer explains, “stored in the world—in books, in folklore, in symphonies and so forth.”
We, today, can still gain intelligence from reading Aristotle or Lao Tzu, whereas chimpanzees and octopuses only learn from those who are currently alive.3
This, Krakauer argues, is the critical difference between us and our primate cousins. The ability to accumulate intelligence through cultural transfers is likely the crucial tipping point, or phase transition, that explains how tiny genetic fluctuations could express themselves in wildly different levels of complex cognition. As Krakauer explains:
Imagine that I gave you an ink that was very volatile, such that when you wrote down text you could only transmit it to at most one other individual, and once those people had it—and tried to propagate it—the message will have disappeared.
If we lived in such a world there would be no culture; because we couldn’t transmit across many generations what we had learned in our lifetime. So just by changing the chemical constituents of the ink—one little chemical change—you make the difference between no culture and a culture. And I think that’s what we have to look for. There’s something about the capability of humans to integrate over time what they have acquired and incrementally, and collectively, add to culture.
This logic neatly resolves the paradox of tiny genetic markers producing enormous shifts in cognitive complexity. Of course, the disappearing ink is a thought experiment—not a literal scientific solution. But it helps provide a framework for understanding how little tweaks, evolutionary flukes if you will, can unlock profound improvements in intelligence. In our complex, non-linear world, small changes often produce big effects.
But even if we accept that logic, there’s a deeper, lingering question: why are some species smart and others…not so much?
III: Cephalopods and the evolution of alien intelligence
In 2008, researchers at a German aquarium grew perplexed: each morning, when they came into work, they found the electricity shut off. With the power shorted out, the filtration pumps turned off, imperiling other animals. Finally, a few researchers volunteered to stay overnight—to figure out what was going on.
To their astonishment, they found the culprit: an octopus named Otto, who was climbing to the rim of his tank and shooting jets of water at an overhead light that was annoying him. He had figured out that several squirts would cause the light to switch off, short-circuiting the electricity in the process. (A similar behavior was observed at the University of Otago in New Zealand, and it was so expensive that they eventually just released the octopus back into the sea).
One intrepid octopus named Inky even managed to permanently escape from his tank. When researchers found he had disappeared, they discovered tracks, showing he walked eight feet across the floor, entered a drainpipe only six inches wide, and proceeded 164 feet to oceanic freedom. (Octopuses4 have soft bodies, so their only limiting factor is their hard beak. They can squeeze through even the smallest cracks. If you haven’t seen this video, watch it).
It’s plausible that Otto’s great escape was the culmination of several reconnaissance missions: at a UK aquarium, one octopus was caught escaping on a nightly basis, exploring to snatch prey from other tanks, then returning back to his own lair, a cephalopod caper worthy of an Arthur Conan Doyle title: The Case of the Disappearing Fish.
Octopuses also seem to take a like or dislike to individual humans, with one feisty octopus squirting water at a particular researcher, but nobody else. Even when researchers wore identical uniforms, the octopus could recognize different faces.
These behaviors are evidence of complex cognition, an advanced level of intelligence few creatures on Earth possess. But what’s most intriguing about octopuses is that they’re so unlike us—and unlike everything else that’s evolved to be a hyper-intelligent species. Other than coleoid cephalopods (octopus, squid, and cuttlefish), all animals with advanced intelligence are vertebrates, from corvids (crows and jays); to cetaceans (whales, dolphins, and porpoises); to primates like ourselves. And birds, great apes, and dolphins are broadly on the same evolutionary lineage, with reasonably similar brain architectures.5
Cephalopods are the only supremely intelligent creatures on the planet that have emerged from the separate evolutionary limb of invertebrates (cold-blooded animals with no backbone that comprise 95 percent of animal species on Earth). But what’s particularly remarkable is how distantly we separated from the octopuses and squid and cuttlefish on the tree of life.
Our last common ancestor was probably a worm-like creature something like 550 million years ago. The mystery of how octopuses evolved complex cognition deepens when we consider that their closest ancestors are species like slugs, snails, oysters, and clams—hardly the kinds of animals we’d choose to invite along to help us win a pub quiz.
With such a distant common relative, it’s no surprise an octopus would be quite unlike ourselves. But the divergences in their brains go well beyond the weird and into the territory of alien-like. An octopus arguably has not one brain, but nine, a hub in its mantle (what we think of as the head) and then eight brains the reside in each of its arms. Approximately three-fifths of the roughly 500 million neurons in an octopus are housed in its arms.6
Even more bizarre, a severed octopus arm can behave similarly whether or not it is attached to the body. For over an hour, the detached arm will still search for food and try to feed a mouth that’s no longer there.7 When the rest of the body of the octopus encounters its own severed arm, it will recognize it as itself—whereas if it’s presented with any other octopus arm, it will realize it is not part of itself. This has raised the possibility that octopuses have several separate hubs of consciousness housed in one body, a profoundly spooky idea that resonates with humans from split-brain experiments.
Octopus camouflage—and that of cuttlefish—is so magical that it’s difficult to believe. And using a special trick from a part of their anatomy known as photophores, many cephalopods can even emit light in a technique known as counter-illumination, matching the exact light intensity of the stars or moonlight from the sky above the ocean, so they won’t cast a conspicuous silhouette that a predator could see from below.
But my favorite cephalopod behaviors are their unique form of sexual mimicry, in which males of a species of cuttlefish are able to make the top of its body look sexy and masculine, while making the bottom of its body mimic the appearance of a female. That way, its potential mate will see the enticing bits, while a rival male looking up from below will think it’s just two females hanging out and won’t interfere. Similarly, when a lady of the opalescent squid variety (Doryteuthis opalescens) wants to rid herself of a pestering male, she’s able to flash a white stripe down her body that appears to be the testes of a male squid—an extreme, clever form of sexual rejection. (Quite an escalation from a woman at a bar giving out a fake phone number).
Many of those examples are evolved traits of strange bodies, not necessarily evidence of advanced cognition. But octopuses are absurdly smart, embodying the Krakauer definition with elegance, as they solve complex problems but make it look easy. They use tools: one has been filmed carrying coconut shells, an exercise that shows a trait of advanced cognition called mental time travel, in which they plan for an unforeseeable future moment when sharks may arrive, hiding their entire body in a bit of brown, hairy, impenetrable armor.
Mimic octopuses are routinely filmed masquerading as flounders, adjusting their body shape, undulating across the ocean floor in convincing cosplay, making it less likely that a predator will nip at one of their vulnerable arms, tucked behind them as they glide across the sea floor.
In another study, octopuses were presented with two similar shells and one odd one. If they grabbed the odd one, they were given a food reward. Soon, they transferred that learning to a more general rule, identifying the odd item out in sets they hadn’t seen previously. Cuttlefish have also passed the marshmallow test.
An octopus may not challenge Max Park for the Rubik’s cube world record, but carrying around foraged body armor in the ocean depths and inferring rules and categories to extract rewards? That is seriously smart.
IV: Live slow and social, die smart?
Yet, octopus intelligence poses a tricky puzzle. For every vertebrate with complex cognition, two main theories of intelligence help explain how it emerged.
The Ecological Intelligence Hypothesis: intelligence emerges to help creatures find food in difficult environments.
The Social Intelligence Hypothesis: creatures that live in social groups require complex cognition to cooperate, deceive, form social bonds, and learn from one another.
The latter, in particular, makes sense if you’re planning to stick around for a while, learn smarter strategies for survival, and teach your young how to behave. These theories match the vertebrate data really well: crows, dolphins, and primates (including us) all have long lives (a minimum of 15+ years); take care of their offspring; and are capable of reproducing multiple times in one lifespan.
By contrast, most cephalopods live alone, survive for between six months and two years; don’t take care of their offspring, and produce children just once, then die.
Researchers have recently proposed that the evolution of advanced cephalopod cognition emerged when they were forced to become more adaptable, and jettisoned their hard shells (which persisted in cousin species like nautiluses). This had a major advantage—flexibility in habitat—which is why cephalopods are found pretty much everywhere in oceans. But it came with a cost: without a shell, they faced an abrupt surge in predators eating them, which required a get-smart-quick scheme, a pressure that led to advanced cognition. The puzzle persists, however. After all, many animals get devoured; few become brainiacs. We don’t have the answers.
Why, other than the fact that octopuses are stupefyingly interesting, should we care about this? Because it implies a profound idea: there are multiple evolutionary pathways and biological architectures that create intelligence. The study of cephalopods can yield new ways of thinking about artificial intelligence, consciousness, and plausible imaginings of unknown alien intelligence.
V: Why we are uniquely stupid
But there’s another lesson we can learn from cephalopods about our own stupidity. What an octopus lacks—which we have in spades—is rigid, stubborn ideology. Our unique ability to reason with generalized concepts, to imagine worlds that don’t exist, to conjure up distorted mental models of how we think reality functions—from outlandish conspiracy theories, to religious and political zealotry—can blind us to obvious truths.
In Fluke, I mention Alfred Wegener, the balloonist who proposed that the continents must have drifted, given how clearly their coastlines fit together like a jigsaw puzzle. Blinded by scientific precepts, what is now plainly obvious to any child who glances at a map of South America and Africa, was resisted—for vast stretches of time—by the world’s smartest thinkers.
Or, more prominent today, consider a conspiracy theorist or political ideologue who will never change their mind, no matter the evidence. That’s a uniquely resilient form of stupidity, more familiar to Marjorie Taylor Greene than to, say, the average porpoise. After all, an octopus or squid may not solve a Rubik’s cube, but cephalopods are unlikely to resist relevant, useful information simply because the data doesn’t match its ideology about how the world should work.
Humans, therefore, arguably possess the widest spectrum of behaviors along the Krakauer definition of intelligence. We are capable of the most astonishing feats of cognition, externalized outside our minds across vast stretches of time and space. But we are also capable of breathtaking stupidity, imagining that it’s a good idea to turn over a nuclear arsenal to Donald Trump, or, at the delightful pinnacles of human beclowning, that we can camouflage ourselves by making our faces invisible with lemon juice.
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When I first came across this story, I couldn’t stop cackling. I love picturing the astonishment on the face of these bumbling crooks when they took a picture with the Polaroid lens facing the wrong way and believed themselves to be invisible. Thank you, McArthur Wheeler, wherever you are, for bringing me so much joy.
As readers of Fluke will recall, octopus eyes are a remarkable example of convergent evolution. We have basically the same eye structure as they do.
Some inter-generational transfers of information may occur through epigenetics—of trauma, for example. But it’s hardly the same as us reading Aristotle in 2024.
Do not e-mail me and tell me it’s “octopi.” (This has happened). It’s not. You are wrong.
Bird brains are a bit different from ours (the neocortex of a mammal has cells organized in layers; the analogous avian pallium is organized with cells in clusters).
We have around 86 billion neurons. Octopuses have similar numbers to dogs.
One species of octopus, the argonaut, is a short king, growing only 10% the size of the female—but he is not deterred, using his third arm, an appendage that doubles as a detachable penis, which he dutifully shoots at the much larger female.
This is one of the best essays I have read in ages. Kudos to Brian.
A quibble: Dunning and Kruger’s work showed that students who were ignorant - not stupid - weren’t aware of their ignorance and thought they’d tested better than they had. They did better when taught what they didn’t know. Not knowing what you don’t know is common, even among the intelligent.