We humans fancy ourselves sophisticated life-forms, and have the science to prove it. We’ve put a rover on Mars, developed theories of our own evolution, and discovered a particle consistent with the Higgs boson. But we are also scratching, sneezing, farting animals, as Robert R. Provine reminds us in his new book “Curious Behavior: Yawning, Laughing, Hiccupping, and Beyond.” And, as far beyond serious scientific study as these vulgar, noisome behaviors might seem, Provine argues that they have much to tell us about being human.
A professor of psychology and neuroscience at the University of Maryland, Baltimore County, Provine is also a practitioner of what he terms “sidewalk neuroscience,” or scientific inquiry into universal, seemingly mundane human behaviors. His work explores some of the same questions that have intrigued thinkers like B.F. Skinner—for example, why there is such dissonance between what people do and what they say about their actions. Provine, however, approaches these problems not psychologically, but through the framework of evolution and biology.
Provine’s research takes him into unusual and sometimes amusing territory: For this book, the professor subjected flatulence to acoustic analysis, tickled chimpanzees, and counted pre-natal hiccups. In the process, he amassed a trove of insights about our evolutionary origins and social programming—how our ability to walk upright allows us to laugh, for example, or how understanding tickling could lead to breakthroughs in robotics.
In exploring the animal underpinnings of our human nature, Provine delves most deeply into actions that are contagious. From chuckling along to laugh tracks to succumbing to outbreaks of yawning to the furtive scratching of New Yorkers terrified of bedbugs, infectious behaviors form a primal part of “the emergence of humans as social, conscious beings,” he says, and yield potential clues as to how we developed empathy and an awareness of ourselves and others.
Looking ahead, Provine has larger ambitions for his “handbook of human universals”: He hopes it will encourage others interested in human nature, from researchers to young students, to delve more deeply into the everyday acts we often hide behind our handkerchiefs.
‘Anything that can be associated with yawns will trigger yawns. Including me, as a yawn scientist...I might become a yawn trigger.’
Provine spoke to Ideas by phone from Columbia, Md.
IDEAS: Why did you decide to study what you call “curious behaviors”?
PROVINE: All the behaviors in the book should be looked at as pieces in a puzzle—they are instinctive human behaviors, universals. These are some of the bedrock of our being....My background is in developmental neuroscience—looking at nerve cells, putting electrodes in them, doing exotic and technologically sophisticated things. I was getting tired of putting electrodes in nerve cells in a windowless room for six or eight hour days. But I was also interested in examining human behaviors using the same kind of rigorous procedures.
IDEAS: How did you choose the particular behaviors featured in your book?
PROVINE: If you’re interested in the neuromechanisms of human behavior, you want to look at behaviors that everyone has, everyone does in the same way, are simple, and easy to study. I was also interested in behaviors that are contagious because they offer insights into how the brain produces and controls behavior, but also give insights into primal social behavior that isn’t learned.
IDEAS: Speaking of contagion, I thought it was daring to put the yawning chapter first. I yawned no fewer than 10 times and had to lie down for a nap. I didn’t have this problem with other chapters, though!
PROVINE: Oh, yes. In the course of our experiments, we found that even reading about yawning could trigger yawns. So anything that can be associated with yawns will trigger yawns. Including me, as a yawn scientist...I might become a yawn trigger.
As for contagion, that has all sorts of implications—we might be looking at the roots of empathy. Empathy can be about understanding or sharing another person’s inner state. But in the case of contagious yawning, it could also be about synchronizing bedtime among members of a tribe.
We have this illusion of ourselves as rational beings who consciously make choices as we go through life. But actually we are following a neurological script that we only partially understand. And we provide ourselves post-hoc rationalizations for what are neurologically generated acts.
IDEAS: In your book, you advance a theory of how our bipedality led to the evolution of speech. How does that work?
PROVINE: All quadrupeds, including chimpanzees, even though they can stand upright and walk short distances...have a one-to-one link between striding and breathing. Just as when you lift a heavy object, you hold your breath....But bipedality frees the thorax of support function...and freed us from the link of one-to-one stride to breathing. With the unlinking of breathing and running, that meant there could be the natural selections for making fancy sounds of laughter as well as speech. So laughter was a step along the path to speech evolution.
IDEAS: Speaking of communication, how does vomiting send a message to others around us?
PROVINE: Well, when we see another person throwing up, they can serve as the canary in the coal mine, the index case to let our brains know that we might have eaten something poisonous, too. So in contagious vomiting, we also throw up, because it’s better to be safe than sorry.
IDEAS: That doesn’t happen because, ew, somebody barfed?
PROVINE: No, you’ve learned to find the sight and smell of a person vomiting disgusting. But babies wouldn’t find the smell of vomit—or even feces—disgusting.
IDEAS: How do emotional tears affect how we react to each other?
PROVINE: A lot of animals have distress calls, but emotional tearing is unique to humans and might solicit caregiving....The study I did on this, we had hundreds of images and a large number of subjects, comparing faces with tears, and then the same faces with tears removed. If you remove the tears, the face looked less sad to the subject. In some cases, they don’t look sad at all. Tears enable us to perceive the sadness of a face.
IDEAS: I was so intrigued by your chapter on tickling as part of how we differentiate between self and other.
PROVINE: Yes. Typically, studies of these things have been driven by a philosophical, not neurological, agenda—Buber’s “I and Thou.” But they haven’t dealt with the issue of what determines the frontiers of your personhood.
With tickle, it presents a novel computation of personhood, because you can’t tickle yourself. If you could...your life would be a giant chain reaction of gooseyness. You’d be constantly startling yourself. It’s important to tell if you’re touching something or someone is touching you....If you can’t make that distinction, there’d be no fine motor control. You’d get a lot less writing done. You’d be constantly startled by your pencil....You want to go through life being afraid of your underwear?
IDEAS: What are the broader implications for this finding?
PROVINE: It seems like a frivolous quirk. But...as we understand the neurological computation, we can build ticklish robots. In other words, robots where you could program the sense of self into them....It’s important for it to be able to tell if it bumps into something or something bumps into it. If something bumps into you, there’s an animate other.
Tickle suggests the breakthrough of understanding the self. And once you understand the computation of self, you understand the computation of other. There’s something there for philosophers, social psychologists, and personality theorists alike.