by Robin Hanson
WHY WE’RE UNAWARE OF BODY LANGUAGE
Let’s now circle back to our original question: Why does so much of our nonverbal signaling take place outside the spotlight of conscious awareness?
The three areas of social life we’ve examined in this chapter—sex, politics, and status—are laced with norms governing our behavior.58 What we may hope to accomplish in each area is often at odds with the interests of others, which can easily lead to conflict. That’s why societies have so many norms to regulate behavior in these areas, and why we (as individuals) must take pains to conduct ourselves discreetly.
As a medium of communication, body language gives us just the cover we need. Relative to spoken language, it’s considerably more ambiguous. While the overall patterns of body language may be consistent, any isolated behavior will have many interpretations.59 Such ambiguity, as we’ve seen in earlier chapters, can be a feature rather than a bug—especially when we’re trying to hide our intentions from others.
Consider how we use our bodies to “say” a lot of things we’d get in trouble for saying out loud. It would be appallingly crass to announce, “I’m the most important person in the room”—but we can convey the same message, discreetly, simply by splaying out on a couch or staring at people while talking to them. Similarly, “I’m attracted to you,” is too direct to state out loud to someone you just met—but a smile, a lingering glance, or a friendly touch on the wrist can accomplish the same thing, with just enough plausible deniability to avoid ruffling feathers.
The point is, relative to spoken messages, nonverbal messages are much harder to pin down precisely, making it easier to avoid accusations of impropriety. In a meeting at work, for example, Peter may use nonverbals to marginalize his rival Jim (e.g., by ignoring him while he speaks). But if Peter is accused of acting “politically,” he’ll quickly deny it, arguing that his accuser has misread the situation. Later, at a party, he may use body language to flirt with another woman. But if his wife accuses him, he’s likely to explain that he was merely being friendly.
Peter himself may not even be fully aware of what he’s doing. At work he may simply think, “Jim is always ruining things,” and not consider his own behavior to be “political.” Similarly, at the party, he may truly believe he’s just being friendly, without any conscious intention to flirt. Nevertheless, in both cases his behavior deserves to be questioned. Whether or not he acknowledges it, part of Peter’s mind would love to see Jim fired, and part of his mind is attracted to the other woman and is curious to see what might happen if he continues “being friendly.”
If Peter introspected carefully enough, he could probably bring himself to notice these motives lurking in the back of his mind—but why bother calling attention to them? The less his Press Secretary knows about these motives, the easier it is to deny them with conviction. And meanwhile, the rest of his brain is managing to coordinate his self-interest just fine.
Body language also facilitates discretion by being less quotable to third parties, relative to spoken language. If Peter had explicitly told a colleague, “I want to get Jim fired,” the colleague could easily turn around and relay Peter’s agenda to others in the office. Similarly, if Peter had asked his flirting partner out for a drink, word might get back to his wife—in which case, bad news for Peter.
This is the magic of nonverbal communication. It allows us to pursue illicit agendas, even ones that require coordinating with other people, while minimizing the risk of being attacked, accused, gossiped about, and censured for norm violations. This is one of the reasons we’re strategically unaware of our own body language, and it helps explain why we’re reluctant to teach it to our children.60
Not all of our nonverbal messages are taboo in this way, of course. We’re all perfectly aware that droopy eyes mean we’re feeling tired, outstretched arms mean we’re feeling proud, and smiles mean we’re feeling happy. It doesn’t fluster us to admit these meanings or to comment on them in conversation. But as soon as someone points out our sex-, politics-, or status-related body language, we begin to fumble about self-consciously. And like a murder suspect turning suddenly awkward during an interrogation, we’re uncomfortable because we have something to hide.
8
Laughter
Humans can be strange. And of all our strange behaviors, surely among the strangest is our tendency to erupt into wild fits of rhythmic gasping and grunting. We contort our faces, clutch our sides, and double over as if in anguish. But far from being painful, this curious activity is considered the height of pleasure. We actively seek it out. We gather in large crowds, eager to experience it together. We even judge our friends, our lovers, and our leaders by their ability to elicit it from us.
Laughter1—chuckles, chortles, giggles, and guffaws—is an innate and universal behavior. We start laughing almost as soon as we’re out of the womb, months before we learn to talk or sing.2 Even infants born blind and deaf, who can’t copy behaviors from their parents or siblings, instinctively know how to laugh.3 And while each culture develops its own distinct language and singing style, laughter sounds pretty much the same in every remote village and bursting metropolis on the planet. As they say, it needs no translation.
Laughter is an involuntary behavior. It’s not something we actively decide to do; our brains simply do it, naturally and spontaneously. In this way, laughter is similar to other involuntary behaviors like breathing, blinking, flinching, hiccuping, shivering, and vomiting. But whereas these are merely physiological, laughter is an involuntary social behavior.4 We use laughter to flirt, bond with friends, mock our enemies, probe social norms, and mark the boundaries of our social groups. It’s a response to social cues, laced with interpersonal significance, and yet “we”—the conscious, deliberate, willful parts of our minds—don’t get to decide when we do it.5
As if that weren’t strange enough, we’re also astonishingly unaware of what laughter means and why we do it. Speculation abounds, but much of it is erroneous, and not just among laypeople. For more than two millennia, many of the Western world’s brightest minds—from Plato and Aristotle to Hobbes and Descartes, and even Freud and Darwin—have been completely mistaken about why we laugh (see Box 10).
Box 10: A Brief History of Laughter
Prior to 1930, according to philosopher John Morreall, there were three main theories of laughter and humor.6
According to the superiority theory (Plato, Aristotle, Thomas Hobbes, and René Descartes7), laughter is fundamentally mean-spirited, a form of mockery, derision, or scorn. The superiority theory says that we laugh primarily at other people, because we feel superior to them. The problems with this theory are that it can’t explain why we laugh when we’re tickled, or why we don’t laugh when we see a beggar on the street.
According to the relief theory (Sigmund Freud, Herbert Spencer), laughter is a physiological process. We laugh whenever a situation initially causes the brain to summon “nervous energy” (to deal with a perceived threat or negative emotion), but then takes away the need for such energy. Unused, the excess energy somehow needs to be dissipated, and convulsive laughter does the trick. In other words, laugher = tension + relief. The main problem with this theory is that there’s no such thing as “nervous energy” sloshing around in our brains. Our brains aren’t hydraulic processes; they’re chemical and electrical. And modern analogs to “nervous energy”—hormones like epinephrine and cortisol—don’t need to be dissipated through laughter.
Finally, the incongruity theory (Immanuel Kant, Arthur Schopenhauer) says we laugh when our expectations are violated, especially in a pleasing way. Incongruity explains why most jokes take the form of a setup followed by a punchline: the setup creates an expectation, which is then violated by the punchline. The main problem with this theory is that it doesn’t explain why incongruity causes us to make sounds8 or how those sounds are used socially.
As we’ll see, there are grains of truth in all these theories. But none of them captures th
e essence of laughter as an evolved social behavior.
For a behavior we perform every day, it’s shocking how alien laughter is to our conscious minds. But while “we” may not understand or control our laughter, our brains are experts at it. They know when to laugh, at which stimuli, and they get it right most of the time, with inappropriate laughter bursting forth only on occasion. Our brains also instinctively know how to interpret the laughter of others, whether by laughing in return or otherwise reacting appropriately. It’s only to “us”—our conscious, introspective minds—that laughter remains a mystery.
On the surface, laughter seems to be all fun and games, an expression of joy. Picture an infant giggling at a game of peekaboo with her father—what could be more wholesome and innocent? But from earlier chapters, we know that ignorance often serves a deceptive purpose; our brains hide certain things from us in order to hide them more effectively from others. This suggests there may be a hidden dark side to laughter. Consider how we often use humor as an excuse to trot out our most taboo subjects: race, sex, politics, and religion. Or how we laugh at people who are different from us or people who aren’t in the room. We can say things in the comedic register that we’d never dream of saying in a straight-faced discussion. The paradox of laughter is that it puts us at ease in social situations, and yet its meaning and purpose seem to reside squarely in our introspective blind spot.
In this chapter we’re going to demystify laughter—to “crack the code” and explain it as clearly as possible. (It turns out there’s a very crisp, satisfying answer.) Then we’ll turn our attention to the darker side of laughter, to investigate what our brains are hiding from us.
THE BIOLOGY OF LAUGHTER
Why do we laugh?
When we’re asked this question in real life—upon laughing at a joke, for example—we might say, “Because it was funny.” In other words, it’s our perception of something humorous that causes us to laugh. This fits the stimulus–response pattern underlying many of our behaviors, especially the involuntary ones, and it has a lot of intuitive appeal. Just as we smile when we’re happy and cry when we’re sad, so too must we laugh in response to some psychological state triggered by humor.
This line of thinking might lead us to wonder about the psychology of humor—a topic fruitfully explored in the book Inside Jokes, for example. But for our purpose in investigating laughter, humor turns out to be a wild goose chase. In part, this is because whatever “humor” turns out to be, we’re still left with the question of why we emit giggles and chuckles in response. Beyond that, we also need to explain why we laugh at non-humorous stimuli like tickling, pillow fights, and roller coasters—or when, as children, we get to explore a new physical environment like snow, water, or a big pile of leaves.
In order to explain laughter, then, we’ll have to look beyond the psychology of humor. And that’s our cue to introduce Robert Provine, a professor of neurobiology at the University of Maryland. Now, Provine wasn’t the first to crack the code of laughter; others, like Max Eastman, had conjectured the solution half a century earlier. But Provine’s research has done more to solidify our understanding of laughter than the legion of armchair theorists who preceded him.
In the 1990s, Provine noticed that the literature on laughter was full of speculative theorizing, but preciously short on actual data. So he resolved to fix this by studying laughter empirically, both in the lab and out “in the wild”—in shopping malls, parks, and other public spaces in contemporary America. He decided to treat laughter as an animal behavior, not unlike a dog’s bark or a bird’s song. “In the spirit of Jane Goodall heading out to Gombe Stream Preserve to study chimpanzees,” writes Provine, “three undergraduate assistants and I set forth on an urban safari to study humans in their natural habitat.”9
This empirical, biological study of laughter produced a few key observations. The most important observation is that we laugh far more often in social settings than when we’re alone—30 times more often, in Provine’s estimate.10 It’s not that we never laugh by ourselves; clearly, sometimes, we do. But laughter is designed, or at least optimized, for social situations. This is one reason TV and radio producers developed “laugh tracks” for their shows. Even canned laughter tricks our brains into thinking we’re in a more social setting than we actually are—and so we’re more likely to laugh.11
The second key observation about laughter is that it’s a vocalization, a sound. And across the animal kingdom, sounds serve the purpose of active communication. Cobras hiss to scare off predators. Dogs bark as a warning sign. Male birds sing to attract females, while baby birds chirp to let their parents know they’re hungry. In all these cases, animals make noise because they want to be heard—because they want to affect their listeners in predictable ways. And so too with laughter. When Provine studied 1,200 episodes of laughter overheard in public settings, his biggest surprise was finding that speakers laugh more than listeners—about 50 percent more, in fact. This makes little sense if we think of laughter as a passive reflex, but becomes clear when we remember that laughter is a form of active communication. Even infants seem to use laughter intentionally, to communicate their emotional state to their interaction partners. Provine describes the “duet” that takes place between mother and baby, where the mother first provides some stimulation, typically in the form of a touch or a tickle, and the baby responds either by laughing (“More! More!”) or by crying, defending, or fussing (“Too much! Stop!”).12 Similarly, an early study at Yale demonstrated that infants laugh much more readily when tickled by their mothers than when tickled by a stranger.13 This kind of laughter isn’t just a knee-jerk physiological reaction; it’s a message used to regulate social interaction.
The final key observation is that laughter occurs even in other species. Specifically, it’s found in all five of the “great apes”—orangutans, gorillas, bonobos, chimpanzees, and humans—although not in any other primates, suggesting an origin in our common ancestor, 12 to 18 million years ago. This evolutionary account is corroborated by the acoustic properties of laughter. By analyzing recorded laughs from each of the great-ape species, researchers were able to reconstruct the same “family tree” of species relationships that we know from genetics. In other words, the more closely related two species are, the more their laughs sound alike.14
Our ape cousins also laugh in many of the same situations as we do—when being tickled by a friendly familiar, for example, or during rough-and-tumble play.15 The chimp Lucy, reared among humans, has even been caught laughing while drunk on alcohol and making funny faces at herself in the mirror.16 And chimps, like humans, laugh more with others than when they’re alone.17
All of this suggests that laughter serves a concrete biological function rooted in animal communication. But what kind of message is so important that our distant ape ancestors evolved an innate signal to convey it?
LAUGHTER IS A PLAY SIGNAL
“Both in man and his primate relatives, laughter marks the boundary of seriousness.”—Alexander Kozintsev18
“I am convinced that a majority of the learned philosophers who have written treatises on laughter and the comic never saw a baby.”—Max Eastman19
According to legend, Archimedes had his iconic “Eureka!” moment in a public bath. Newton had his moment under an apple tree. And Eastman—an American journalist and roving intellectual—had his flash of insight about laughter while playing with an infant. Here’s how he describes that insight in his 1936 book The Enjoyment of Laughter:
The next time you are called upon to entertain a baby, I will tell you what to do. Laugh, and then make a perfectly terrible face. If the baby is old enough to perceive faces . . . he will laugh too. But if you make a perfectly terrible face all of a sudden, without laughing, he is more likely to scream with fright. In order to laugh at a frightful thing he has to be in a mood of play.20
The core idea here is that laughter is necessarily coupled with play. If the mood is serious, a terrible face
will elicit a scream, but if the mood is playful, the very same stimulus will elicit a laugh. As Eastman says, “No definition of humor, no theory of wit, no explanation of comic laughter, will ever stand up, which is not based upon the distinction between playful and serious.”21
Play, according to zoologists, is a mode of behavior in which animals, especially young ones, explore the world and practice skills that will be important later in life. It’s a voluntary, nonfunctional (i.e., impractical22) activity undertaken in a safe, relaxed setting.23 And it’s extremely common in the animal kingdom. Every mammal engages in play—think wrestling or play biting—and many birds do as well. Even reptiles and amphibians have been caught in the act.
But while we humans often play by ourselves (e.g., with Legos), recall that we laugh mostly in the presence of others. So what communicative purpose does laughter serve in the context of play?
Gregory Bateson, a British anthropologist, figured it out during a trip to the zoo. He saw two monkeys engaged with each other in what looked like combat, but clearly wasn’t real. They were, in other words, merely play fighting. And what Bateson realized was that, in order to play fight, the monkeys needed some way to communicate their playful intentions—some way to convey the message, “We’re just playing.” Without one or more of these “play signals,” one monkey might misconstrue the other’s intentions, and their playful sparring could easily escalate into a real fight.24
