The Scientist Who Discovered Fish Smarts
WHY YOU SHOULD CARE
Because humans aren’t the only ones who are mean in high school.
By Nathan Siegel
Get a haircut, and any number of things can determine whether you’ll walk out feeling like a thousand bucks or like you’ve just been fitted for a bowl. There’s the stylist’s skill, for starters. But it also matters how much you’re paying, whether the stylist thinks his next customer will tip better, if other customers are watching — even whether there are other tonsorial artists nearby you might patronize if this one botches your cut.
We humans and our primate relatives are about the only species with brains big enough to track such social cues. Or so we thought. Now you can add fish to the list — yes, those scaly critters you might serve wrapped in seaweed on rice. Our finny friends, it turns out, are due for an IQ upgrade, and for that, they have behavioral ecologist Redouan Bshary to thank. Social evolution theorists, meanwhile, have had to rethink one of their long-held notions that linked the evolution of sizable brains to the demands of keeping up with other primates.
Over 15 years of watching fish in their natural habitats and putting them to the test in game theory experiments, Bshary basically proved that they have the capacity to cheat, punish, cooperate and rank other fish in social hierarchies. His findings uncovered a previously hidden world of complex social behaviors, akin in some ways to the regimented cooperation early researchers discovered in ant colonies. But where an ant colony is a kind of superorganism that evolved to function like a single entity, little of the sort is true for fish. So if they’re capable of acting like the in-crowd at your local high school, something else has to be at work.
Whatever that is, it suggests that humans might want to take themselves down a peg — or at least think up a different reason to explain why humans brains evolved so large. Bshary himself, though, gives you no reason to doubt what the big human brain can accomplish. The Bavarian-born scientist, now ensconced at the University of Neuchâtel in Switzerland, has published his work in top scientific journals such as Science and Nature. And he sports an excellent cranium of his own, framed by a fringe of grayish dark hair that runs across the back of his scalp. He’s patient as he explains his work in slightly nasal, German-accented English, occasionally shrugging, tilting his head for emphasis or letting a half-smile play across his face as he describes fish antics.
Bshary grew up in the small 5,000-person town of Feldafing, near Munich. His extended family lived on a large piece of land, and as a child, Bshary built dams and tried to catch fish in a stream that ran alongside the property. (But don’t go looking for foreshadowing here; Bshary says he didn’t find fish particularly interesting at the time.) Later on, after a false start in theater — in his 20s, he says, he loved Stanley Kubrick and Impressionist artists like Dalí — Bshary caught the evolutionary biology bug and started studying cooperation among monkeys.
Cleaner fish were less likely to cheat when other clients were watching. And client fish wouldn’t return to a crappy cleaner.
Then he heard about an amazing ecosystem of barrier reef fish that involve so-called cleaner fish, which nibble parasites off “client” fish in exchange for food. After a dive-training session in a snowy southern German lake, Bshary packed up and headed to the Egyptian desert. He lived on the beach for months at a time, diving in the Red Sea from dusk till dawn. (During those nomadic days of isolation from broader society, Bshary still found himself subject to social cues: He fell for one of his field assistants, and later married her.) Bshary misses being out in the field, getting his hands dirty. Nowadays, he says, he “pays the price” for his long research trip in the form of a mile-high workload.
During these excursions, he documented a few fascinating discoveries. For one, cleaner fish would often cheat. Instead of picking off the parasites, they would bite off the nutritious coating of the client fish, causing it to jolt. Bshary was then able to show that cleaner fish were less likely to cheat when other clients were watching. Similarly, if there were a lot of cleaners to choose from, client fish wouldn’t return to a crappy cleaner, instead opting for the competition — “just like a big city,” says Bshary. If there were only a few cleaners, clients would chase (read: punish) the bad cleaners — “just like in a small town,” he says. To buttress his findings, Bshary re-created similar situations in the lab and found much the same behavior.
Despite the extra work Bshary has caused them, evolutionary biologists generally admire his science. But some question whether it really proves that those roly-poly fish heads are home to complex social-network models. Dutch primatologist Carel van Schaik, for instance, tells OZY that fish may just have some sort of limited hardwired social mechanisms, ones that are “not flexible, not based on learning or insight” and that operate only in very specific circumstances.
Which in a weird way kind of describes Bshary himself — though not on the learning or insight front, of course. His father, a repairman for a Munich gadget company, immigrated from Tangier, Morocco, to Germany, where he met Bshary’s mother; they moved to the countryside soon after. Bshary still hasn’t full connected to the big-city life. He doesn’t own a cellphone, preferring to enjoy the cocktails he makes with friends without technology nearby. Facebook and Twitter? No way, he says. Minds like Bshary’s prefer the open water.