The question that SETI scholars are debating mirrors one at the heart of this chapter: As our hominid predecessors increasingly lived and worked in close proximity with one another, gathering and distributing plants, fruits, and seeds, sharing the meat of a kill, tending to the needs of vulnerable offspring, moving through gatherings of potential mates and vigilant rivals, what behaviors allowed them to navigate such conflict-rife contexts in cooperative fashion? The classical Greeks had their own answer, one that will anticipate the theme of this chapter—the smile.
As Angus Trumble details in A Brief History of the Smile, in the third to fifth centuries BC, Greek artisans began sculpting the Kouros, a life-sized sculpture that has been found throughout mainland Greece, Asia Minor, and islands in the Aegean Sea. It is a sublimely dynamic sculpture, with upright posture, left foot moving forward, and hands gently clenched in determination. The most captivating aspect of the Kouros, though, is its smile. It is at once modest, poised, expectant, and brimming with contained delight.
In its heyday, the Kouros served as an all-purpose symbol of goodness. It was commonly placed in ceremonial settings as an offering to the gods, to communicate reverence toward the higher powers that controlled the quirks of fate on the earthly ground of Greek life. It was a common presence at funerals, no doubt for those well-off enough to afford such memorializing, serving as an image of the deceased and as a symbol of the gods who would protect the soul of the deceased. For the Greeks, the Kouros represented the soul embodied in the human form.
Evolutionary analysis will tell a similar story about the human smile. In evolution’s toolbox of adaptations that promote cooperation, the smile is perhaps the most potent tool. The smile is visible from hundreds of feet. It triggers, science has discovered, activation in reward centers of the brain. It soothes the stress-related physiology of smiler and perceiver alike. The smile smoothes the rough edges of our social life, creating a medium of benevolent exchange. The right kind of smile brings the good in others to completion. It is one of the first acts of jen in primate evolution.
At stake in our evolutionary analysis of the smile are answers to two questions. The first is straightforward, but has proven to be a surprisingly prickly source of controversy: What does the smile mean? People smile in almost every imaginable context: seeing a loved one, being sentenced to prison, enjoying ice cream and the appalling cooking of a dear friend, hearing that one is pregnant and receiving dire medical news, winning lotteries and losing Olympic competitions. The English language possesses a few words for smiles—“smile,” “grin,” “smirk,” “beam”—really a paucity of concepts that masks the rich complexity of the realm of smiles. A better understanding of what the smile means will be found by turning to facial anatomy and evolutionary analysis.
A deeper question, however, is at play in our search for the origins of the smile: What are the roots of human happiness? If the right kind of smile is synonymous with happiness, which intuition and dozens of scientific studies suggest is the case, then our search back in time for the social contexts in which the smile emerged is really a search back in time for the origins of human happiness. And this journey would begin with Charles Darwin’s intuitions, and end in studies of smile-like behavior in our more egalitarian primate relatives.
MISLED BY THE LAUGHTER OF CHILDREN
Sometimes vivid images produced by careful observation lead us astray. Such was the case in Charles Darwin’s analysis of the smile. Darwin kept detailed recordings of the development of the emotional lives of his children. In writing about the emergence of laughter, he discerned a reliable pattern. At around fifty days his children would begin to smile. Gradually, with age, in similar contexts such as tickling, which he resorted to as scientist and devoted father, he would see, about two months later, the rudimentary signs of laughter—“little bleating noises”—that systematically were released during exhalation.
From these transfixing observations, Darwin arrived at his thesis about the smile: that it is the first trace of the laugh. Given this assumption, he then answered—rightly, I believe—the question of the morphological origins of the smile. Why does the smile take its characteristic form of lips retracted upward and occasionally to the side? Why do we not signal a sense of amusement with an eyebrow flash, a cheek flicker or nostril flare, or any of the other thousands of possible configurations of facial muscles? Darwin’s answer is found in two claims. First, a nod to the principle of antithesis: We smile as a public offering of high spirits because the shape of the smile, with its curved movements upward, is the antithesis of the tightened lips, the lip corners pulled down, the bared teeth, of anger. The smile signals the antithetical state of its opposite expression, that of anger. The second observation is in keeping with Darwin’s analysis of the physical actions that facial expression are part of: The smile’s retraction of the mouth corners up, and occasionally, sideways, enables the kinds of exhalation and vocalizations seen in laughter.
Darwin’s thesis, then, is that the smile is the first stage of the laugh, the larva to the butterfly, the acorn to the oak tree. There is something deeply satisfying in this view. Perhaps the Greeks had it right, that there are indeed two swaths of human emotional life: the tragic realm, a serious, fate-altering spectrum of emotions like anger, fear, and sadness, associated with tragic losses, threats, and injustices; and a comedic realm, defined by playful, lighthearted emotion grounded in laughter. Perhaps all of our positive states—enthusiasm, hope, gratitude, love, awe—originate in our ability to take alternative perspectives upon our current state of affairs: a prerequisite of the laugh.
Parsimonious and pleasing as this may be, it’s wrong. When primatologist Signe Preuschoft put Darwin’s smile-as-laughter thesis to the test by examining when various nonhuman primates show smilelike and laughterlike displays, she found that these two displays occur in much different social contexts, and toward much different ends. The smile and the laugh originate in distinct slices of early primate life, and have subsequently followed separate evolutionary trajectories as they worked their way into the human emotional repertoire and our nervous systems.
SILENT BARED-TEETH AND RELAXED OPEN-MOUTH DISPLAYS
In her careful observations of primates, in particular several different macaque species, Preuschoft has catalogued numerous displays that convey affiliative, cooperative intent. These include pout faces and lip smacks (which Darwin wrote about—see chapter 2)—no doubt predecessors to the succor-seeking sulking we see in three-year-olds, and of course, the kiss. The most common affiliation-seeking displays in primates, and most central to our understanding of human smiling and laughter, are the silent bared-teeth display and the relaxed open-mouth display.
Across species, primates resort to the silent bared-teeth display to appease and to signal submissiveness, weakness, and social fear in contexts in which the likelihood of conflict and aggression is high, for example when nearing dominant primates. The silent bared-teeth display is most typically seen in submissive primates and is usually accompanied by inhibited posture, protective body movements such as shoulder and neck tightening, or hands hovering around the face for obvious defensive purposes. Thankfully, this display often short-circuits aggression, triggering reconciliation in the dominant monkey—affiliative grooming and embracing.
In humans, the silent bared-teeth display is evident in our deferential smile, which signals thoughtful, at times fearful, attention to the concerns of others. This smile involves the activity of two muscles: the zygomatic major, which pulls the lip corners upward, and the risorius, which pulls the lower lip sideways. I first encountered the deferential smile empirically in an early study of teasing, in which I had two high-and two low-status fraternity brothers tease one another. As they ripped into each other in the profane gutter language of young men living together in tight quarters, the low-status guys were ten times more likely to show deferential smiles. A good time was had by all, but it was the low-status guys who signaled their subordinate po
sitions with this smile.
The relaxed open-mouth display, in contrast, is observed, Preuschoft notes, in fewer primate species. It is accompanied by panting and staccato breathing, and on occasion bursts of grunt-or howl-like vocalizations and boisterous body movements. Quite clearly, the relaxed open-mouth display is the primate predecessor to the human laugh. Importantly, Preuschoft has found that the relaxed open-mouth display occurs in a radically different set of social contexts than those associated with the silent bared-teeth display: It precedes and accompanies the pyrotechnics of primate play—chasing, nuzzling, gnawing, rough-and-tumble somersaults and cavorting in the branches of trees.
Preuschoft’s analysis of these two primate displays makes it difficult, even for the ardently faithful, to continue entertaining Darwin’s hypothesis that the smile is the first stage of the laugh. No longer tenable as well is the pleasing inference that our capacity for play is the most rudimentary element of positive emotion. Instead, we must conclude that smiling and laughter have distinct evolutionary origins. The smile emerged to facilitate cooperative and affiliative proximity. The laugh emerged to promote play and levity. They are tokens of different swaths of positive emotion, and different facets of the meaningful life.
A VOCABULARY OF SMILES
During the summer following my freshman year in college, I decided to teach myself classical guitar while living at home in Penryn, California, a tiny rural backwater named after an island in Wales. Two weeks into thick-fingered attempts at “Classical Gas,” my mother had had enough. A week later I found myself donning the brown polyester and golden arches insignia of the McDonald’s uniform, serving burgers, fries, Chicken McNuggets, and gooey sundaes to sunburned revelers on their way to underaged drinking and debauchery at the rocky rivers in the foothills of the Sierras or the noisy waterskiing lakes. Each and every day at 11:10 AM a middle-aged man arrived, strode to the counter in shoes that made a strange clicking sound, and, with somber brown eyes and Lincolnesque sideburns, placed the same order: four plain hamburgers, with nothing on the gray patties and buns that dissolved upon touch, and a cup of black coffee, which I had to refill a dozen or so times in the span of the thirty-six minutes he reliably took to finish his lunch. He became a Sisyphus-like commentary on my fate: the minimum-wage undermining of my musical career and the missed opportunities for summertime revelry. My manager, a good-hearted, optimistic soul, recognized my deep despair and offered managerial guidance straight out of some McDonald’s handbook: just smile. I felt deeply oppressed, filling the regular customer’s Styrofoam cup with another round of coffee, smiling as I delivered his cup of joe.
I can assure you that I was not smiling the smile that evolution has produced, and which we will soon dissect, and which promotes goodwill between individuals. Much more likely, I was emitting the service industry smile, the one that signals that the customer is always right, that the sale should always come first. Sociologist Arlie Hochschild has argued that this smile is part of the emotional labor required of so many service-oriented jobs and the tip of the iceberg of alienation from the fruits of human labor. Research shows that when workers smile in the service industry, for example when greeting customers at a 7-11 counter, customers are more satisfied and actually more likely to consume. As the bottom line is enhanced, however, workers experience a problematic disconnect, Hochschild argues, between the emotions they display to the outer world and the feelings they experience within. This disconnect has parallels to recent studies by my colleague Ann Kring of schizophrenics. Contrary to longstanding assumptions about schizophrenia and flat affect, schizophrenics have been shown to feel the emotions that you and I feel but not to express them in the face. Service industry jobs produce a form of schizophrenia: We may experience feelings of emptiness and quiet frustration, or a deep ennui, but we display to the world the smile of satisfaction.
How then can we provide a coherent analysis of a category of behaviors—smiles—that includes my McD smile as well as the loving smiles of old friends and parents and children? At first glance, the empirical literature on the smile yields similarly paradoxical findings: People have been shown to smile when winning, losing, watching a film of an amputation, eating sweets, facing adversaries, experiencing pain, feeling affection toward loved ones. The answer is provided by Paul Ekman, and it involves looking away from the lip corners to that wellspring of the soul—the eyes.
A vocabulary of smiles comes sharply into focus when we consider the activity of the happiness muscle, the orbicularis oculi. This muscle surrounds the eyes and when contracted leads to the raising of the cheek, the pouching of the lower eyelid, and the appearance of those dreaded crow’s-feet—the most visible sign of happiness—which the Botox industry is trying to wipe out of the vocabulary of human expression. People may think they look prettier following Botox injections, but their partners will receive fewer clues to their joy, love, and devotion.
Ekman has called smiles that involve the activation of the zygomatic major muscle and the orbicularis oculi the Duchenne or D smile, in honor of the French neuroanatomist Guillaume Benjamin Amand Duchenne (1806–1875), who first discovered the visible traces of the activity of orbicularis oculi. Smiles that do not involve the activity of the happiness muscle, the orbicularis oculi, are sensibly known as non-Duchenne or non-D smiles. To try your hand at this subtle distinction between Duchenne and non-Duchenne smiles, see if you can detect which is which in the photographs below (answers provided on chapter 6).
Dozens of scientific studies speak to the importance of parsing the heterogeneous category of smiles according to the activity of the orbicularis oculi muscle. Duchenne smiles differ morphologically in many ways from the many other smiles that do not involve the action of the orbicularis oculi muscle. They tend to last between one and five seconds, and the lip corners tend to be raised to equal degrees on both sides of the face. Smiles missing the action of the orbicularis oculi and likely masking negative states can be on the face for very brief periods (250 milliseconds) or very long periods (a lifetime of polite smiling by oppressed airline stewardesses and fast-food servers). Non-D smiles are more likely to be asymmetrical in the intensity of muscle firing on the two sides of the face.
D smiles tend to be associated with activity in the left anterior portion of the frontal lobes, a region of the brain preferentially activated during positive emotional experiences. Non-D smiles, in contrast, are associated with activity in the right anterior portion of the brain—a region associated with the activation of negative emotion. When a ten-month-old is approached by his or her mother, the face lights up with the D smile; when a stranger approaches, the same infant greets the approaching adult with a wary non-D smile.
And importantly, several studies have found that Duchenne and non-Duchenne smiles, brief two-to three-second displays differing only in the activation of the orbicularis oculi muscle, map onto entirely different emotional experiences. For example, in a longstanding collaboration with my friend George Bonanno, a pioneer in the study of trauma (see chapter 7), we interviewed middle-aged adults six months after their deceased spouse had passed away. These individuals were asked to describe their relationship with their deceased spouse for six minutes. I spent a summer coding the occurrence of Duchenne and non-Duchenne smiles from videotapes of these narratives. We then related measures of bereaved participants’ D and non-D smiles to their reports of how much enjoyment, anger, distress, and fear they felt during the interview, which we gathered immediately after the participants had finished talking about their deceased spouse.
Portrayed in the table below are the correlations between how much participants showed these brief Duchenne and non-Duchenne smiles and their ensuing self-reports of emotion gathered moments later. Positive scores indicate that the more they showed the particular smile during the six-minute interview, the more they subsequently felt the particular emotion listed on the left. Negative correlation values reveal the opposite, that the more the participant smiled in Duchenne or n
on-Duchenne fashion, the less of the emotion they felt. Asterisks indicate that the observed correlation was statistically significant, and not likely produced by chance.
DUCHENNE SMILES
NON-DUCHENNE SMILES
ENJOYMENT
.35*
–.25*
ANGER
–.28*
.09
DISTRESS
–.49*
–.16
FEAR
–.31*
.04
What is impressive about these data is that very brief Duchenne smiles involving the activity of the orbicularis oculi were associated with increased feelings of enjoyment during the conversation, and reduced feelings of anger, distress, and fear. Non-Duchenne smiles were associated with the opposite pattern of experience—reduced feelings of enjoyment and none of the negative emotions.
The Duchenne/non-Duchenne distinction is the first big distinction in a taxonomy of different smiles. One kind of smile involves the orbicularis oculi muscle, and accompanies high spirits and goodwill. As we shall see, when other movements are added to the D smile, people can communicate different positive states like love, awe, and desire. A second kind of smile is the non-D smile, which reflects the attempt to mask some underlying negative state. In Emotions Revealed, Ekman deconstructed the non-D smile into a dizzying array of smiles, including pained smiles, fearful smiles, contemptuous smiles, and submissive smiles.
Born to Be Good_The Science of a Meaningful Life Page 11