Thumbs, Toes, and Tears

by Chip Walter

  We all learned in our grade school science classes that the autonomic nervous system controls “mindless” operations such as breathing and, heartbeat as well as the basic functioning of our kidneys and brains. But the autonomic nervous system is itself divided into two other systems: the sympathetic and the parasympathetic. The sympathetic nervous system evolved to prepare us for action—physically, mentally, and emotionally. When we are scared, for example, the sympathetic nervous system fires off the messages that tell our bodies to skedaddle or stand our ground and prepare to fight.

  The traditional thinking for years was that because the sympathetic system gets us emotionally excited, it also must be the system that causes us to cry. But now many scientists think it may be the other way around. After all, after every fight or flight, we have to settle down. If we continued to run in overdrive, we would blow an aorta, or have a stroke, and that would be the end of that. Given the dangerous nature of the lives our ancestors lived, it wouldn’t have been long before the species would have been done in by cerebrovascular accidents or coronary thrombosis. So the parasympathetic nervous system returns our neurotransmitters, heart rate, and hormones to normal. Quite possibly we cry not because we are getting agitated and upset, but because it is a way for our nervous system to bring us back into equilibrium.

  One study reveals, for example, that if the nerves central to the sympathetic system are paralyzed, patients cry more. But when important parasympathetic nerves are damaged, they cry less. If crying was driven by the sympathetic nervous system, it would be the other way around. In other words, we don’t cry because we are upset, which is the way it feels, but because we are trying to get over being upset. That may be the real reason why we feel better after we have a good cry.

  Looked at this way, it is easier to see why crying might have evolved. Like so much that evolution favors, crying is a survival strategy, like eating food or sleeping or breathing air, all things we do to stabilize, get into our comfort zones, and stay alive.

  Still, none of this explains why we cry tears. We could just as easily, and tearlessly, howl like a coyote or scream at the top of our lungs like our chimp cousins, and still feel some relief. But where are the evolutionary advantages in tears? After all, they blur our vision and add to the vulnerability our scrambled emotions have already created. Who among us would feel comfortable knowing that the pilot flying our coast-to-coast jet, or the doctor performing brain surgery, was in tears? Yet somehow they must help; otherwise the laws of evolution, would have booted them from the gene pool long ago.

  In 1975 an Israeli biologist, Amotz Zahavi, conceived an interesting theory about why animals behave—on the surface, at least—in ways that don’t seem to have much evolutionary purpose, but on closer observation turn out to be perfectly sensible. Many of these behaviors, he pointed out, seem not only baffling, but often downright counterproductive. Why does a peacock have enormous, colorful tail feathers when the natural result of having them must be that it slows the bird down, draws the attention of predators, and makes it difficult to fly? Or why does a gazelle, when it senses a lion is about to attack, bound straight up into the air like a pogo stick before making its exit?5

  Zahavi calls these traits and behaviors examples of the “handicap principle.” We see them everywhere in the natural world, from the huge antlers of bull elks to the loud squawking of hungry baby birds. On the surface the traits make no sense for the simple reason that they come at a high price—they require energy and resources, and they draw dangerous amounts of attention.

  But according to Zahavi they also serve as powerful forms of communication. In fact, the bigger the handicap, the more powerful the communication. An antelope’s first vertical bound, for example, immediately puts it at a disadvantage. It has lost precious seconds it could have used to put distance between it and the predator that intends to make a meal of it. But a leap like that also sends a message that says, “I am so fast and can leap so high, there is no chance you are going to catch me. So don’t waste your energy.” Often the lion or cheetah poised for pursuit absorbs the message, performs a quick cost-benefit analysis, and walks away in search of more sickly prey incapable of a five-foot vertical leap.

  In a strange way, messages like this have introduced a kind of primal form of truth and honesty into the natural world. They can’t be faked because they are too costly. If a peacock could fake big, heavy tail feathers and wasn’t truly healthy enough to support them, it would quickly find itself a meal for any fox or wildcat that called its bluff. Those genes would not be passed along. The same would be the case if an antelope were capable of faking one bound, but was then unable to head off in the opposite direction at lightning speed. All of this is nature’s way of saying “If you can’t walk the walk, don’t talk the talk.”6

  Being “truthful” may explain the origins of our tears. Crying, like laughing, is a unique form of human communication, and its roots are just as primal. But unlike laughing, which we all do all the time, crying is reserved for special occasions. That we don’t often cry tears of emotion indicates that they come at a cost, a Zahavian handicap that requires extra energy or invites undue attention. Because tears are costly and rare, and because they are cried only when very deep emotions are being felt, they are not easily faked and send an unmistakable signal that the feelings behind them are absolutely real.

  More often than not, tears signal that we want help and consolation because we are in pain—physical or emotional. But it also applies to feelings of pride or joy. When a father cries at the sight of his newborn baby and his wife sees this, it bonds them and says, in effect, “We are in this together.” Cornelius has observed that our response to a person weeping tends to be profound, and reinforces the connections we feel for one another. Our hearts go out to people, even total strangers with whom we have nothing in common.

  This cuts both ways, however. When we see someone crying, but we don’t see any tears, we are immediately suspicious. Tearless crying simply isn’t as authentic. Cornelius tested the dynamics of this, too. Over the past six years he and his students have been gathering still photographs and video images from newsmagazines and television programs, all of them of people crying real and visible tears. When they found a particularly appropriate image, they prepared two versions: one, the original, with tears; and another, with the tears digitally erased.

  For this experiment they gathered a group of people and sat them down one at a time in front of a computer monitor to watch a slide show. Each slide presented two pictures: one tearful, the other a different picture with the tears secretly erased. No participants were allowed to see the same picture with and without tears. Cornelius’s team then asked each participant to explain what emotion they thought the person in each photograph was experiencing, and how they would respond to a person with that particular look on their face.

  The test’s observers universally registered that pictures of people with tears in their eyes or on their cheeks were feeling and expressing deeper emotions—mostly sadness, grief, and mourning—than those who were tearless. But when participants looked at pictures where the tears had been digitally removed, they often concluded that the people in them were feeling any number of emotions; from sadness to awe to boredom. Cornelius concluded that tears alone sent a specific and powerful emotional message.

  But there was another wrinkle. The tearful pictures often elicited two very different responses from those who looked at them. About half of the observers felt people crying tears were saying “Help me” or “Comfort me.” The other half felt that the people in the images wanted to be left alone. This seems, says Cornelius, to have less to do with the expressions on the faces in the pictures and more to do with the attitude of the people looking at them. Sometimes crying is a call for help and attention, but sometimes it is a way of saying we are vulnerable and want room and space to deal with what is upsetting us until we can get back to normal. A contradiction? Not necessarily, says Cornelius. Trying to hid
e our tears still sends an honest signal about our state of mind. It still says we are in trouble, even want comfort, just not necessarily from someone else right at that time. Paradoxically, if someone refuses comfort or tries to hide their crying, it makes them seem even more vulnerable.

  Tears carry a lot of expressive weight. If we evolved our outsized brains mainly to handle the complex social and personal interactions to which we pay tireless attention, then tears add one more true and powerful arrow to the quiver from which we draw our many forms of human communication.

  Dr. Paul MacLean, chief of the National Institute of Mental Health’s Laboratory of Brain Evolution and Behavior, has speculated that human crying has its origins in distress and separation calls similar to those of young primate monkeys and chimps. This means that like laughter, the sounds of crying have their roots in the hoots and howls of the jungle. He has speculated that in the course of evolution, the early use of fire and the smoke that rose from funeral pyres irritated our ancestors’ eyes, and in time became associated with sadness. It is a theory, and obviously our lacrimal glands somehow wired themselves into the emotional centers of our brain. But the truth is there is no way of knowing how precisely.

  Evolution operates by random chance, after all. A genetic mutation enters the world packaged in the creature that exhibits it, whether it is colorful feathers or tears. If that creature survives, the adaptation does, too, and is passed along. And if it works, it spreads out into the next generation and so on. Crying, as MacLean has theorized, may well trace its origins to the hoots and calls of our precursors. Countless species come into the world squawking or screaming for attention. Perhaps there is some clue here into how primal calls somehow morphed into the tears we cry.

  …

  When we enter the world, our loud bawl of a birth cry sends the indisputable message that we have arrived. Later cries become more sophisticated: In babies, they communicate hunger, pain, loneliness, and discomfort. During the first eight months of life, human infants don’t actually cry tears. They don’t have the plumbing for it. Nor is it necessary in those early months, because they are so clearly helpless that every cry is believed.

  But in toddlerhood the situation changes. Crying becomes subtler, a kind of simple language, and it can be used to manipulate. After all, children, even as they grow older, want the attention of their parents, and since crying has been their most effective way of getting it, they continue to use it, even when they don’t absolutely need help. The babies of rhesus macaque monkeys even behave this way. They cry out to their mothers in infancy, and tend to cry even more at about the time their mothers wean them. (Macaque monkeys can only become pregnant again when they stop breast-feeding. Contrary to popular belief, this is not true of human mothers.) At first macaque mothers come running, but as the cries increase, they begin to respond less because so many turn out to be false alarms. The macaque moms become more skeptical, and eventually the infants cry less because it isn’t working.7

  Crying wolf like this, however, also may have made tears even more effective. Every parent has experienced the tearless crying of a child who is unhappy and wants attention but isn’t really in deep trouble (the scientific term for this is whining).8 So among the first signals parents look for when a child cries are real tears, a sure sign that their toddler truly needs help (as opposed to just wanting a bag of Snickers at the grocery store). Presumably the same would have been true for our ancestors. Tears would have put the same visual exclamation point on any howl, moan, or grimace for them as much then as they do today for us.

  At some unknown and unknowable time the gap between the reflexive tears that a poke in the eye creates and the emotional tears a broken heart brings on closed. During the past six million years, enormous changes took place in our ancestors, much of it from the neck up. Not only have our brains doubled in size and then doubled again, but also our faces have changed and so have our ways of conveying emotion with them. Their rich, expressive musculature evolved by chance, but remained with us because it helped us more precisely communicate, and sometimes manipulate, one another.

  This may explain how tearful, human crying evolved. Somewhere at some time the genes that control the parts of the brain associated with the experience and expression of emotion became connected, literally, to the lacrimal gland that sits above each of our eyes. This would have been a first in the primate world. Chimps and gorillas will grimace and howl, snarl and moan. They feel sad or hurt or scared, but they cannot cry tears of pain or frustration or joy any more than they can stand up and walk around erect as an English butler or begin talking in full sentences.

  Perhaps sometime long ago, when our ancestors were still living chimp-like in Africa’s rain forests, one was born with the odd ability to cry tears when she was upset, but because it didn’t serve any useful purpose in her social world, the gene eventually disappeared. The personal interactions of jungle-living chimps are highly complex, but not nearly as complex as ours. Tears might have amounted to communication overkill, just as evolving the many facial muscles we have today would have been.

  But for our kind the situation was different. Our ancestors lived outside the relative safety of the jungle. And because they did, they needed one another more than their forestbound cousins. And if they needed one another more, then they also needed to communicate more effectively. So as their brains and social interactions grew progressively more multifaceted, one feeding on the other, their need to bond and communicate, manipulate and read one another’s minds also accelerated. Complex relationships beg for increasingly complex minds and increasingly complex forms of communication. Language was one mighty adaptation that emerged for this very reason. Tears, given the potent, highly visible messages they send, were another. They became a kind of supreme form of body language.

  But wouldn’t speech have sufficed to express our strongest emotions? Wouldn’t the precision of words trumped crying, even tearful crying? Maybe, except that truly strong emotions often linger beyond the reach of words, and tears do what syntax and syllables can’t. We all know the feeling, whether it is profound sadness, frustration, anger, pride, or pain. Crying expresses emotions that words simply can’t.

  Maybe it is not so much that the lacrimal glands of chimps are not wired into their brains (because they are), but that there is no oversized neocortex in there to which it can make a connection. Plato wrote twenty-five hundred years ago that our natures are driven, like a chariot, by two horses, one dark and wild (our emotions), and the other controlled and logical (our intellect). Intellect, he said, must control our dark side. And in some ways, the evolution of the prefrontal cortex supports that simile. But it is more complicated than that. Our intellect doesn’t simply suppress our visceral, animal feelings. It also inborns them. And maybe this is the central reason why crying is a uniquely human trait. It marries raw emotion with a brain capable of reflecting on those howling, primal feelings. That is why we cry. Our simian cousins, gifted and intelligent as they are, don’t have the capacity for the powerful marriage of thoughts and emotions. They can feel rage, frustration, or loss, but they do not reflect on them. The random emergence of genes that connected the emotional and intellectual parts of our brains to lacrimal glands that sit above our eyes gave us a new way to express those elusive feelings. And in the bargain we gained an emotional stamp we can put on our cries for help that no other creatures possess.

  VI

  Kissing

  Chapter 10

  The Language of Lips

  kisses are a better fate than wisdom.

  —e. e. cummings

  If you are ever in doubt as to whether to kiss a pretty girl, always give her the benefit of the doubt.

  —Thomas Carlyle

  Kisses are like tears; the only real ones are the ones you can’t hold back.

  —Anonymous

  Who doesn’t care for a Fetching Smooch, a long-lasting liplock, a lingering kiss? We have an affection for kissing because our lips enj
oy the thinnest layer of skin on the human body, and the nerve endings there, and in our tongues and mouths, send messages to the brain that define the word “pleasure.” This explains why the brain devotes great swathes of real estate to the nerves needed to operate these parts of our bodies—more, even, than it devotes to moving our entire torso. No part of our anatomy is better tuned to the things that touch them. Lips, it seems, are all about sensation. And so we kiss—furtively, lasciviously, shyly, hungrily, and exuberantly. We give ceremonial kisses, affectionate kisses, social kisses, kisses of death, and kisses that give life. When passion takes a grip, we lock together exchanging not just fluids and breath, scents, and tastes but souls and minds, feelings, secrets, and emotions that defy words and run circles around syntax. It is as though a circuit has been completed and the currents of two hearts have directly fused into something entirely new, which, in a sense, they have.

  You are unlikely to notice when you are locked in a passionate, soul-searching kiss, but your pulse rate and blood pressure are rising, your pupils are dilating, and you are breathing (when you can get a breath) more deeply.1 Your kissing is also reducing your chances of tooth decay, relieving stress, burning calories, and increasing your self-esteem.2 Part of the reason your self-esteem is rising is because lips meeting lips releases waves of the neurotransmitters norepinephrine, dopamine, and phenylethylamine (PEA), which in turn attach to the pleasure receptors in your brain that generate the same feelings of euphoria we feel when we laugh or exercise hard or take certain mood-enhancing drugs such as cocaine or heroin. This is why you will almost never be depressed when kissing.

  Kissing also requires your face to work hard. According to Margaret H. Harter, at the Kinsey Institute for Research in Sex, Gender, and Reproduction, even when we pucker up for nothing more than a standard hello or good-bye, thirty lip muscles go to work.3 While they do, neural connections that run from the lips, tongue, cheek, and nose up to the brain enable kissers to sense temperature, taste, smell, and movement, which in turn drive the production of those pleasure-making neurotransmitters. Of the twelve cranial nerves that affect brain function, five are in play when we kiss. If we each generate our own personal weather, you might say kissing makes an excellent barometer for detecting it.