These are ancient questions. Philosophers have been exasperated by the problem of why one of humanity’s finest achievements, its sense of humor, is expressed with the sort of crude abandonment associated with animals. There can be no doubt that laughter is inborn. The expression is a human universal, one that we share with our closest relatives, the apes. A Dutch primatologist, Jan van Hooff, set out to learn under which circumstances apes utter their hoarse, panting laughs, and concluded that it has to do with a playful attitude. It’s often a reaction to surprise or incongruity—such as when a tiny ape infant chases the group’s top male, who runs away “scared,” laughing all the while. This connection with surprise is still visible in children’s games, such as peekaboo, or jokes marked by unexpected turns, which we save until the very end, appropriately calling them “punch lines.”
Human laughter is a loud display with much teeth baring and exhalation (hence the gasping for air) that often signals mutual liking and well-being. When several people burst out laughing at the same moment, they broadcast solidarity and togetherness. But since such bonding is sometimes directed against outsiders, there is also a hostile element to laughter, as in ethnic jokes, which has led to the speculation that laughter originated from scorn and derision. I find this hard to believe, though, given that the very first chuckles occur between mother and child, where such feelings are the last things on their minds. This holds equally for apes, in which the first “playface” (as the laugh expression is known) occurs when one of the mother’s huge fingers pokes and strokes the belly of her tiny infant.
The Correspondence Problem
What intrigues me most about laughter is how it spreads. It’s almost impossible not to laugh when everybody else is. There have been laughing epidemics, in which no one could stop and some even died in a prolonged fit. There are laughing churches and laugh therapies based on the healing power of laughter. The must-have toy of 1996—Tickle Me Elmo—laughed hysterically after being squeezed three times in a row. All of this because we love to laugh and can’t resist joining laughing around us. This is why comedy shows on television have laugh tracks and why theater audiences are sometimes sprinkled with “laugh plants”: people paid to produce raucous laughing at any joke that comes along.
The infectiousness of laughter even works across species. Below my office window at the Yerkes Primate Center, I often hear my chimps laugh during rough-and-tumble games, and cannot suppress a chuckle myself. It’s such a happy sound. Tickling and wrestling are the typical laugh triggers for apes, and probably the original ones for humans. The fact that tickling oneself is notoriously ineffective attests to its social significance. And when young apes put on their playface, their friends join in with the same expression as rapidly and easily as humans do with laughter.
Shared laughter is just one example of our primate sensitivity to others. Instead of being Robinson Crusoes sitting on separate islands, we’re all interconnected, both bodily and emotionally. This may be an odd thing to say in the West, with its tradition of individual freedom and liberty, but Homo sapiens is remarkably easily swayed in one emotional direction or another by its fellows.
This is precisely where empathy and sympathy start—not in the higher regions of imagination, or the ability to consciously reconstruct how we would feel if we were in someone else’s situation. It began much simpler, with the synchronization of bodies: running when others run, laughing when others laugh, crying when others cry, or yawning when others yawn. Most of us have reached the incredibly advanced stage at which we yawn even at the mere mention of yawning—as you may be doing right now!—but this is only after lots of face-to-face experience.
Yawn contagion, too, works across species. Virtually all animals show the peculiar “paroxystic respiratory cycle characterized by a standard cascade of movements over a five to ten second period” that defines the yawn. I once attended a lecture on involuntary pandiculation (the medical term for stretching and yawning) with slides of horses, lions, and monkeys—and soon the entire audience was pandiculating. Since it so easily triggers a chain reaction, the yawn reflex opens a window onto mood transmission, an essential part of empathy. This makes it all the more intriguing that chimpanzees yawn when they see others yawn.
This was first demonstrated at Kyoto University, where investigators showed apes in the laboratory the videotaped yawns of wild chimps. Soon the lab chimps were yawning like crazy. With our own chimps, we have gone one step further. Instead of showing them real chimps, we play three-dimensional animations of an apelike head going through a yawnlike motion. Devyn Carter, the technician who put these animations together, said he’d never yawned as much as during this particular job. Our apes also watch animations of a head merely opening and closing its mouth a couple of times, but they only yawn in response to the animated yawns. Their yawns look absolutely real, including maximal opening of the mouth, eye-closing, and head-rolling.
Yawn contagion reflects the power of unconscious synchrony, which is as deeply ingrained in us as in many other animals. Synchrony may be expressed in the copying of small body movements, such as a yawn, but also occurs on a larger scale, involving travel or movement. It is not hard to see its survival value. You’re in a flock of birds and one bird suddenly takes off. You have no time to figure out what’s going on: You take off at the same instant. Otherwise, you may be lunch.
The animated yawns of an apelike head (similar to this one) induce real yawns in watching apes.
Or your entire group becomes sleepy and settles down, so you too become sleepy. Mood contagion serves to coordinate activities, which is crucial for any traveling species (as most primates are). If my companions are feeding, I’d better do the same, because once they move off, my chance to forage will be gone. The individual who doesn’t stay in tune with what everyone else is doing will lose out like the traveler who doesn’t go to the restroom when the bus has stopped.
The herd instinct produces weird phenomena. At one zoo, an entire baboon troop gathered on top of their rock, all staring in exactly the same direction. For an entire week, they forgot to eat, mate, or groom. They just kept staring at something in the distance that no one could identify. Local newspapers were carrying pictures of the monkey rock, speculating that perhaps the animals had been frightened by a UFO. But even though this explanation had the unique advantage of combining an account of primate behavior with proof of UFOs, the truth is that no one knew the cause except that the baboons clearly were all of the same mind.
The power of synchrony can be exploited for good purposes, as when horses were trapped on a piece of dry pasture in the middle of a flooded area in the Netherlands. Twenty horses had already drowned, and there were plenty of attempts to save the others. One of the more radical proposals was for the army to build a pontoon bridge, but before this was tried a far simpler solution came from the local horse riding club. Four brave women on horses mixed with the stranded herd, after which they splashed through a shallow area like pied pipers, drawing the rest with them. The horses walked most of the way, but had to swim a few stretches. In a triumph of applied animal knowledge, the riders reached terra firma followed by a single file of about one hundred horses.
Movement coordination both reflects and strengthens bonds. Horses that pull a cart together, for example, may become enormously attached. At first they jostle and push and pull against each other, each horse following its own rhythm. But after years of working together, the two horses end up acting like one, fearlessly pulling the cart at breakneck speed through water obstacles during cross-country marathons, complementing each other, and objecting to even the briefest separation as if they have become a single organism. The same principle operates among sled dogs. Perhaps the most extreme case was of a husky named Isobel, who after having turned blind still ran along perfectly with the rest based on her ability to smell, hear, and feel them. Occasionally, Isobel ran lead tandem with another husky.
In Dutch bicycle culture, it’s common to have a passe
nger on the backseat. So as to follow the rider’s movements, the person in the rear needs to hold on tightly—which is one reason that boys like to offer girls a ride. Bicycles turn not just by steering but also by leaning, so the passenger needs to lean the same way as the rider. A passenger who’d keep sitting up straight would literally be a pain in the behind. On motorcycles, this is even more critical. Their higher speed requires a deeper tilt in turns, and lack of coordination can be disastrous. The passenger is a true partner in the ride, expected to mirror the rider’s every move.
Sometimes, a mother ape returns to a whimpering youngster who is unable to cross the gap between two trees. The mother first swings her own tree toward the one the youngster is trapped in, and then drapes her body between both trees as a bridge. This goes beyond mere movement coordination: It’s problem-solving. The female is emotionally engaged (mother apes often whimper as soon as they hear their offspring do so), and adds an intelligent evaluation of the other’s distress. Tree-bridging is a daily occurrence in traveling orangutans, in which mothers regularly anticipate their offspring’s needs.
Even more complex are instances in which one individual takes charge of coordination between two others, as described by Jane Goodall with respect to three wild chimpanzees: a mother, Fifi, and her two sons. One son, Freud, had hurt his foot so badly that he was barely able to walk. Mother Fifi usually waited for him, but sometimes moved off before he was ready to limp after her. Her younger son, Frodo, proved more sensitive:
Three times when this happened Frodo stopped, looked from Freud to his mother and back, and began to whimper. He continued to cry until Fifi stopped once more. Then Frodo sat close to his big brother, grooming him and gazing at the injured foot, until Freud felt able to continue. Then the family moved on together.
This is not unlike my own personal experience. My mother has six sons, who all tower head and shoulders over her. Nevertheless, she has always been the leader of the pack. When she became older and frailer, however—which happened only in her late eighties—we had trouble adjusting. We’d step out of a car, for example, briefly help our mother out, but then walk briskly toward the restaurant or whatever place we were visiting, talking and laughing. We’d be called back by our wives, who’d gesture at our mother. She couldn’t keep up and needed an arm to lean on. We had to adjust to this new reality.
Some of these examples are more complex than mere coordination: They involve assuming the perspective of someone else. Or, as in Goodall’s and my family’s account, alerting another to the situation of a third. The one thread that runs through all of these examples, however, is coordination. All animals that live together face this task, and synchrony is key. It is the oldest form of adjustment to others. Synchrony, in turn, builds upon the ability to map one’s own body onto that of another, and make the other’s movements one’s own, which is exactly why someone else’s laugh or yawn makes us laugh or yawn. Yawn contagion thus offers a hint at how we relate to others. Remarkably, children with autism are immune to the yawns of others, thus highlighting the social disconnect that defines their condition.
Body-mapping starts early in life. A human newborn will stick out its tongue in response to an adult doing so, and the same applies to monkeys and apes. In one research video, a tiny baby rhesus monkey intently stares at the face of an Italian researcher, Pier Francesco Ferrari, who slowly opens and closes his mouth several times. The longer the monkey watches the scientist, the more its own mouth begins to mimic his movements in a gesture that looks like the typical lip-smacking of its species. Lip-smacking signals friendly intentions and is as significant for monkeys as is the smile for humans.
I must say that I find neonatal imitation deeply puzzling. How does a baby—whether human or not—mimic an adult? Scientists may bring up neural resonance or mirror neurons, but this hardly solves the mystery of how the brain (especially one as naïve as that of a neonate) correctly maps the body parts of another person onto its own body. This is known as the correspondence problem: How does the baby know that its own tongue, which it can’t even see, is equivalent to the pink, fleshy, muscular organ that it sees slipping out from between an adult’s lips? In fact, the word know is misleading, because obviously all of this happens unconsciously.
A baby rhesus monkey stares at an experimenter and mimics his repeated mouth-opening.
Body-mapping between different species is even more puzzling. In one study, dolphins mimicked people next to their pool without any training on specific behavior. A man would wave his arms, and the dolphins would spontaneously wave their pectoral fins. Or a man would lift up a leg, and the dolphins would raise their tails above the water. Think about bodily correspondence here, or in the case of a good friend of mine, whose dog started dragging her leg within days after he had broken his own. In both cases it was the right leg. The dog’s limp lasted for weeks, but vanished miraculously once my friend’s cast had come off.
As Plutarch said, “You live with a cripple, you will learn to limp.”
The Art of Aping
Finding himself in front of the cameras next to his pal President George W. Bush, former British prime minister Tony Blair—known to walk normally at home—would suddenly metamorphose into a distinctly un-English cowboy. He’d swagger with arms hanging loose and chest puffed out. Bush, of course, strutted like this all the time, and once explained how back home, in Texas, this is known as “walking.”
Children often emulate the same-sex parent.
Identification is the hook that draws us in and makes us adopt the situation, emotions, and behavior of those we’re close to. They become role models: We empathize with them and emulate them. Thus children often walk like the same-sex parent, or mimic their tone of voice when they pick up the phone. American playwright Arthur Miller described how it works:
Nothing was more enjoyable than mimicry. I was about the height of my father’s back pocket, from which his handkerchief always hung out, and for years I pulled the corner of my handkerchief out exactly the same distance.
Imitation is also an anthropoid forte, as reflected in the verb “to ape.” Give a zoo ape a broom, and he’ll move it across the floor the way the caretaker does every day. Give her a rag and she’ll soak it and wring it out before applying it to a window. Hand him a key, and you’re in trouble! But even though all of this is common knowledge, some scientists have been casting doubt on ape imitation. It just isn’t there, they say. Do these scientists have a point, or might they have been testing their apes the wrong way?
In a typical experiment, an ape faces an unfamiliar white-coated experimenter, who sits outside the cage to demonstrate a novel tool that has no meaning in the ape’s environment. After, say, five standardized demonstrations the tool is handed to the ape to see how she’ll use it. Never mind that apes dislike strangers, and that it’s always harder to relate to another species than one’s own. Apes do poorly in these tests compared with children. But then again, the children aren’t kept behind bars, and happily sit on their mothers’ laps. They are being talked to, and most important, they’re dealing with their own kind. They obviously feel perfectly at ease and have no trouble relating to the experimenter. Even though these studies seem to compare apples and oranges, they have fueled claims of a cognitive gap between apes and children.
Soon the inevitable happened: Imitation was elevated to a uniquely human skill. Never mind that such claims are always tricky, which is why they’re being adjusted every couple of years, and that animals learn remarkably easily from companions. Examples range from birds or whales picking up songs from one another to the picnic wars between bears and people in the American wilderness. The bears invent new tricks all the time (they’ve learned, for example, that jumping up and down on top of a specific brand of car will pop open all of its doors), which then spread like wildfire through the population (resulting in warning signs at park entrances for the owners of these particular cars). Clearly, bears notice one another’s successes. At the very leas
t, human uniqueness claims should be downgraded to something more reasonable, such as that our imitation is more developed than that of other animals. But even then I’d be cautious, because our own research has fully restored faith in the aping skills of apes. By eliminating the human experimenter, we have gotten quite different results from the above studies. Given a chance to watch their own kind, apes copy every little detail they see.
Let me start with spontaneous imitation. Small infants in our chimpanzee colony sometimes get a finger stuck in the wire fence. Hooked the wrong way into the mesh, the finger cannot be extracted by force. Adults have learned not to pull at the infant, who always manages to free itself in the end. In the meantime, however, the entire colony has become agitated by the infant’s screams: This is a rare but dramatic event analogous to a wild ape getting caught in a poacher’s snare.
On several occasions, we have seen other apes mimic the victim’s situation. The last time, for example, when I approached to assist I was greeted with threat barks from both the mother and the alpha male. As a result, I stayed back. One older juvenile came over to reconstruct the event for me. Looking me in the eyes, she inserted her finger into the mesh, slowly and deliberately hooking it around, and then pulling as if she too had gotten caught. Then two other juveniles did the same at a different location, pushing each other aside to get their fingers in the same tight spot they had found for this game. These juveniles themselves may long ago have experienced this situation for real, but now their charade was prompted by what had happened to the infant.
Our chimps obviously haven’t read the scientific literature that says imitation is a way of reaching a goal or gaining rewards. They do so spontaneously, often without gains in mind. It’s so much a part of their everyday life that I set up an ambitious research project together with a British colleague, Andy Whiten, who had been thinking along the same lines. In contrast to previous studies, we wanted to know how well apes learn from one another. From an evolutionary viewpoint, it doesn’t really matter what they learn from us—all that matters is how they deal with their own kind.
The Age of Empathy Page 6
