How Emotions Are Made: The Secret Life of the Brain

First Mariner Books edition 2018

Copyright © 2017 by Lisa Feldman Barrett

Illustrations by Aaron Scott

All rights reserved. No part of this book may be used or reproduced in any manner whatsoever without written permission except in the case of brief quotations embodied in critical articles and reviews. For information, address HarperCollins Publishers, 195 Broadway, New York, NY 10007.

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Library of Congress Cataloging-in-Publication Data

Names: Barrett, Lisa Feldman, author.

Title: How emotions are made : the secret life of the brain / Lisa Feldman Barrett.

Description: Boston : Houghton Mifflin Harcourt, 2017.

Identifiers: LCCN 2016038354 (print) | LCCN 2017004323 (ebook) | ISBN 9780544133310 (hardback) | ISBN 9780544129962 (ebook)

ISBN 9781328915436 (pbk.)

Subjects: LCSH: Emotions. | Emotions—Sociological aspects. | Brain. | BISAC: PSYCHOLOGY / Emotions. | PSYCHOLOGY / Neuropsychology. | SCIENCE / Philosophy & Social Aspects. | SCIENCE / Life Sciences / Neuroscience.

Classification: LCC BF561 .B337 2017 (print) | LCC BF561 (ebook) | DDC 152.4—dc23

LC record available at https://lccn.loc.gov/2016038354

Cover design by David Drummond

Cover image based on © Shutterstock

Author photograph © 2017 Mark Karlsberg

v8.0921

For Sophia

Introduction:

The Two-Thousand-Year-Old Assumption

On December 14, 2012, the deadliest school shooting in U.S. history took place at Sandy Hook Elementary School in Newtown, Connecticut. Twenty-six people inside the school, including twenty children, were massacred by a lone gunman. Several weeks after this horror, I watched the governor of Connecticut, Dannel Malloy, give his annual State of the State speech on television. He spoke in a strong and animated voice for the first three minutes, thanking individuals for their service. And then he began to address the Newtown tragedy:

We have all walked a very long and very dark road together. What befell Newtown is not something we thought possible in any of Connecticut’s beautiful towns or cities. And yet, in the midst of one of the worst days in our history, we also saw the best of our state. Teachers and a therapist that sacrificed their lives protecting students.¹

As the governor spoke the last two words, protecting students, his voice caught in his throat ever so slightly. If you weren’t paying close attention, you might have missed it. But that tiny waver devastated me. My stomach instantly knotted into a ball. My eyes flooded. The TV camera panned to the crowd where other people had started to sob too. As for Governor Malloy, he stopped speaking and was gazing downward.

Emotions like Governor Malloy’s and mine seem primal—hardwired into us, reflexively deployed, shared with all our fellow humans. When triggered, they seem to unleash themselves in each of us in basically the same way. My sadness was like Governor Malloy’s sadness was like the crowd’s sadness.

Humanity has understood sadness and other emotions in this way for over two thousand years. But at the same time, if humanity has learned anything from centuries of scientific discovery, it’s that things aren’t always what they appear to be.

The time-honored story of emotion goes something like this: We all have emotions built-in from birth. They are distinct, recognizable phenomena inside us. When something happens in the world, whether it’s a gunshot or a flirtatious glance, our emotions come on quickly and automatically, as if someone has flipped a switch. We broadcast emotions on our faces by way of smiles, frowns, scowls, and other characteristic expressions that anyone can easily recognize. Our voices reveal our emotions through laughter, shouts, and cries. Our body posture betrays our feelings with every gesture and slouch.

Modern science has an account that fits this story, which I call the classical view of emotion. According to this view, the waver in Governor Malloy’s voice launched a chain reaction that began in my brain. A particular set of neurons—call it the sadness circuit—leaped into action and caused my face and body to respond in a certain, specific way. My brow furrowed, I frowned, my shoulders stooped, and I cried. This proposed circuit also triggered physical changes inside my body, causing my heart rate and breathing to speed up, my sweat glands to activate, and my blood vessels to constrict.* This collection of movements on the inside and outside of my body are said to be like a fingerprint that uniquely identifies sadness, much like your own fingerprints uniquely identify you.

The classical view of emotion holds that we have many such emotion circuits in our brains, and each is said to cause a distinct set of changes, that is, a fingerprint. Perhaps an annoying coworker triggers your anger neurons, so your blood pressure rises; you scowl, yell, and feel the heat of fury. Or an alarming news story triggers your fear neurons, so your heart races; you freeze and feel a flash of dread. Because we experience anger, happiness, surprise, and other emotions as clear and identifiable states of being, it seems reasonable to assume that each emotion has a defining underlying pattern in the brain and body.

Our emotions, according to the classical view, are artifacts of evolution, having long ago been advantageous for survival, and are now a fixed component of our biological nature. As such, they are universal: people of every age, in every culture, in every part of the world should experience sadness more or less as you do—and more or less as did our hominin ancestors who roamed the African savanna a million years ago. I say more or less because no one believes that faces, bodies, and brain activity look exactly the same each time someone is sad. Your heart rate and breathing and blood flow won’t always change by the same amount. Your brow might furrow slightly less by chance or by custom.²

Emotions are thus thought to be a kind of brute reflex, very often at odds with our rationality. The primitive part of your brain wants you to tell your boss he’s an idiot, but your deliberative side knows that doing so would get you fired, so you restrain yourself. This kind of internal battle between emotion and reason is one of the great narratives of Western civilization. It helps define you as human. Without rationality, you are merely an emotional beast.

This view of emotions has been around for millennia in various forms. Plato believed a version of it. So did Hippocrates, Aristotle, the Buddha, René Descartes, Sigmund Freud, and Charles Darwin. Today, prominent thinkers such as Steven Pinker, Paul Ekman, and the Dalai Lama also offer up descriptions of emotions rooted in the classical view. The classical view is found in virtually every introductory college textbook on psychology, and in most magazine and newspaper articles that discuss emotion. Preschools throughout America hang posters displaying the smiles, frowns, and pouts that are supposed to be the universal language of the face for recognizing emotions. Facebook even commissioned a set of emoticons inspired by Darwin’s writings.³

The classical view is also entrenched in our culture. Television shows like Lie to Me and Daredevil are predicated on the assumption that your innermost feelings are exposed by your heart rate or facial movements. Sesame Street teaches children that emotions are distinct things inside us seeking expression in the face and body, as does the Pixar movie Inside Out. Companies like Affectiva and Realeyes offer to help businesses detect their customers’ feelings through emotion analytics. In the NBA draft, the Milwaukee Bucks evaluate a player’s psychological, character and personality issues and assess team chemistry from facial expressions. And for several decades, the U.S. Federal Bureau of Investigation (FBI) based some of its advanced agent training on the classical view.⁴

More significantly, the classical view of emotion is embedded in our social institutions. The American legal system assumes that emotions are part of an inherent animal nature and cause us to perform foolish and even violent acts unless we control them with our rational thoughts. In medicine, researchers study the health effects of anger, supposing that there is a single pattern of changes in the body that goes by that name. People suffering from a variety of mental illnesses, including children and adults diagnosed with autism spectrum disorder, are taught how to recognize facial configurations for specific emotions, ostensibly to help them communicate and relate to others.

And yet . . . despite the distinguished intellectual pedigree of the classical view of emotion, and despite its immense influence in our culture and society, there is abundant scientific evidence that this view cannot possibly be true. Even after a century of effort, scientific research has not revealed a consistent, physical fingerprint for even a single emotion. When scientists attach electrodes to a person’s face and measure how facial muscles actually move during the experience of an emotion, they find tremendous variety, not uniformity. They find the same variety—the same absence of fingerprints—when they study the body and the brain. You can experience anger with or without a spike in blood pressure. You can experience fear with or without an amygdala, the brain region historically tagged as the home of fear.

To be sure, hundreds of experiments offer some evidence for the classical view. But hundreds more cast that evidence into doubt. The only reasonable scientific conclusion, in my opinion, is that emotions are not what we typically think they are.

So what are they, really? When scientists set aside the classical view and just look at the data, a radically different explanation for emotion comes to light. In short, we find that your emotions are not built-in but made from more basic parts. They are not universal but vary from culture to culture. They are not triggered; you create them. They emerge as a combination of the physical properties of your body, a flexible brain that wires itself to whatever environment it develops in, and your culture and upbringing, which provide that environment. Emotions are real, but not in the objective sense that molecules or neurons are real. They are real in the same sense that money is real—that is, hardly an illusion, but a product of human agreement.⁵

This view, which I call the theory of constructed emotion, offers a very different interpretation of the events during Governor Malloy’s speech. When Malloy’s voice caught in his throat, it did not trigger a brain circuit for sadness inside me, causing a distinctive set of bodily changes. Rather, I felt sadness in that moment because, having been raised in a certain culture, I learned long ago that sadness is something that may occur when certain bodily feelings coincide with terrible loss. Using bits and pieces of past experience, such as my knowledge of shootings and my previous sadness about them, my brain rapidly predicted what my body should do to cope with such tragedy. Its predictions caused my thumping heart, my flushed face, and the knots in my stomach. They directed me to cry, an action that would calm my nervous system. And they made the resulting sensations meaningful as an instance of sadness.

In this manner, my brain constructed my experience of emotion. My particular movements and sensations were not a fingerprint for sadness. With different predictions, my skin would cool rather than flush and my stomach would remain unknotted, yet my brain could still transform the resulting sensations into sadness. Not only that, but my original thumping heart, flushed face, knotted stomach, and tears could become meaningful as a different emotion, such as anger or fear, instead of sadness. Or in a very different situation, like a wedding celebration, those same sensations could become joy or gratitude.

If this explanation doesn’t make complete sense or even sounds counterintuitive so far, believe me, I am right there with you. After Governor Malloy’s speech, as I came back to myself, wiping my tears, I was reminded that no matter what I know about emotions as a scientist, I experience them much as the classical view conceives them. My sadness felt like an instantly recognizable wave of bodily changes and feelings that overwhelmed me as a reaction to tragedy and loss. If I were not a scientist using experiments to reveal that emotions are in fact made and not triggered, I too would trust my immediate experience.

The classical view of emotion remains compelling, despite the evidence against it, precisely because it’s intuitive. The classical view also provides reassuring answers to deep, fundamental questions like: Where do you come from, evolutionarily speaking? Are you responsible for your actions when you get emotional? Do your experiences accurately reveal the world outside you?

The theory of constructed emotion answers such questions differently. It’s a different theory of human nature that helps you see yourself and others in a new and more scientifically justified light. The theory of constructed emotion might not fit the way you typically experience emotion and, in fact, may well violate your deepest beliefs about how the mind works, where humans come from, and why we act and feel as we do. But the theory consistently predicts and explains the scientific evidence on emotion, including plenty of evidence that the classical view struggles to make sense of.

Why should you care which theory of emotion is correct? Because belief in the classical view affects your life in ways you might not realize. Think about the last time you went through airport security, where taciturn agents of the Transportation Security Administration (TSA) X-rayed your shoes and evaluated your likelihood as a terrorist threat. Not long ago, a training program called SPOT (Screening Passengers by Observation Techniques) taught those TSA agents to detect deception and assess risk based on facial and bodily movements, on the theory that such movements reveal your innermost feelings. It didn’t work, and the program cost taxpayers $900 million. We need to understand emotion scientifically so government agents won’t detain us—or overlook those who actually do pose a threat—based on an incorrect view of emotion.⁶

Now imagine that you’re in a doctor’s office, complaining of chest pressure and shortness of breath, which may be heart attack symptoms. If you’re a woman, you’re more likely to be diagnosed with anxiety and sent home, whereas if you’re a man, you’re more likely to be diagnosed with heart disease and receive lifesaving preventive treatment. As a result, women over age sixty-five die more frequently of heart attacks than men do. The perceptions of doctors, nurses, and the female patients themselves are shaped by classical view beliefs that they can detect emotions like anxiety, and that women are inherently more emotional than men . . . with fatal consequences.⁷

Belief in the classical view can even start wars. The Gulf War in Iraq was launched, in part, because Saddam Hussein’s half-brother thought he could read the emotions of the American negotiators and informed Saddam that the United States wasn’t serious about attacking. The subsequent war claimed the lives of 175,000 Iraqis and hundreds of coalition forces.⁸

We are, I believe, in the midst of a revolution in our understanding of emotion, the mind, and the brain—a revolution that may compel us to radically rethink such central tenets of our society as our treatments for mental and physical illness, our understanding of personal relationships, our approaches to raising children, and ultimately our view of ourselves. Other scientific disciplines have seen revolutions of this kind, each one a momentous shift away from centuries of common sense. Physics moved from Isaac Newton’s intuitive ideas about time and space to Albert Einstein’s more relative ideas, and eventually to quantum mechanics. In biology, scientists carved up the natural world into fixed species, each having an ideal form, until Charles Darwin introduced the concept of natural selection.

Scientific revolutions tend to emerge not from a sudden discovery but by asking better questions. How are emotions made, if they aren’t simply triggered reactions? Why do they vary so much, and why have we believed for so long that they have distinctive fingerprints? These questions in and of themselves can be delightfully interesting to ponder. But taking pleasure in the unknown is more than just a scientific indulgence. It’s part of the spirit of adventure that makes us human.

In the pages that follow, I invite you to share that adventure with me. Chapters 1–3 introduce the new science of emotion: how psychology, neuroscience, and related disciplines are moving away from the search for emotion fingerprints and instead asking how emotions are constructed. Chapters 4–7 explain how, exactly, emotions are made. And chapters 8–12 explore the practical, real-world implications of this new theory of emotions on our approaches to health, emotional intelligence, child-rearing, personal relationships, systems of law, and even human nature itself. To close the book, chapter 13 reveals how the science of emotion illuminates the age-old mystery of how a human brain creates a human mind.

1

The Search for Emotion’s Fingerprints

Once upon a time, in the 1980s, I thought I would be a clinical psychologist. I headed into a Ph.D. program at the University of Waterloo, expecting to learn the tools of the trade as a psychotherapist and one day treat patients in a stylish yet tasteful office. I was going to be a consumer of science, not a producer. I certainly had no intention of joining a revolution to unseat basic beliefs about the mind that have existed since the days of Plato. But life sometimes tosses little surprises in your direction.

It was in graduate school that I felt my first tug of doubt about the classical view of emotion. At the time, I was researching the roots of low self-esteem and how it leads to anxiety or depression. Numerous experiments showed that people feel depressed when they fail to live up to their own ideals, but when they fall short of a standard set by others, they feel anxious. My first experiment in grad school was simply to replicate this well-known phenomenon before building on it to test my own hypotheses. In the course of this experiment, I asked a large number of volunteers if they felt anxious or depressed using well-established checklists of symptoms.¹

I’d done more complicated experiments as an undergraduate student, so this one should have been a piece of cake. Instead, it crashed and burned. My volunteers did not report anxious or depressed feelings in the expected pattern. So I tried to replicate a second published experiment, and it failed too. I tried again, over and over, each experiment taking months. After three years, all I’d achieved was the same failure eight times in a row. In science, experiments often don’t replicate, but eight consecutive failures is an impressive record. My internal critic taunted me: not everyone is cut out to be a scientist.

When I looked closely at all the evidence I had collected, however, I noticed something consistently odd across all eight experiments. Many of my subjects appeared to be unwilling, or unable, to distinguish between feeling anxious and feeling depressed. Instead, they had indicated feeling both or neither; rarely did a subject report feeling just one. This made no sense. Everybody knows that anxiety and depression, when measured as emotions, are decidedly different. When you’re anxious, you feel worked up, jittery, like you’re worried something bad will happen. In depression you feel miserable and sluggish; everything seems horrible and life is a struggle. These emotions should leave your body in completely opposite physical states, and so they should feel different and be trivial for any healthy person to tell apart. Nevertheless, the data declared that my test subjects weren’t doing so. The question was . . . why?

As it turned out, my experiments weren’t failing after all. My first botched experiment actually revealed a genuine discovery—that people often did not distinguish between feeling anxious and feeling depressed. My next seven experiments hadn’t failed either; they’d replicated the first one. I also began noticing the same effect lurking in other scientists’ data. After completing my Ph.D. and becoming a university professor, I continued pursuing this mystery. I directed a lab that asked hundreds of test subjects to keep track of their emotional experiences for weeks or months as they went about their lives. My students and I inquired about a wide variety of emotional experiences, not just anxious and depressed feelings, to see if the discovery generalized.

These new experiments revealed something that had never been documented before: everyone we tested used the same emotion words like angry, sad, and afraid to communicate their feelings but not necessarily to mean the same thing. Some test subjects made fine distinctions with their word use: for example, they experienced sadness and fear as qualitatively different. Other subjects, however, lumped together words like sad and afraid and anxious and depressed to mean I feel crappy (or, more scientifically, I feel unpleasant). The effect was the same for pleasant emotions like happiness, calmness, and pride. After testing over seven hundred American subjects, we discovered that people vary tremendously in how they differentiate their emotional experiences.

A skilled interior designer can look at five shades of blue and distinguish azure, cobalt, ultramarine, royal blue, and cyan. My husband, on the other hand, would call them all blue. My students and I had discovered a similar phenomenon for emotions, which I described as emotional granularity.²

Here’s where the classical view of emotion entered the picture. Emotional granularity, in terms of this view, must be about accurately reading your internal emotional states. Someone who distinguished among different feelings using words like joy, sadness, fear, disgust, excitement, and awe must be detecting physical cues or reactions for each emotion and interpreting them correctly. A person exhibiting lower emotional granularity, who uses words like anxious and depressed interchangeably, must be failing to detect these cues.

I began wondering if I could teach people to improve their emotional granularity by coaching them to recognize their emotional states accurately. The key word here is accurately. How can a scientist tell if someone who says I’m happy or I’m anxious is accurate? Clearly, I needed some way to measure an emotion objectively and then compare it to what the person reports. If a person reports feeling anxious, and the objective criteria indicate that he is in a state of anxiety, then he is accurately detecting his own emotion. On the other hand, if the objective criteria indicate that he is depressed or angry or enthusiastic, then he’s inaccurate. With an objective test in hand, the rest would be simple. I could ask a person how he feels and compare his answer to his real emotional state. I could correct any of his apparent mistakes by teaching him to better recognize the cues that distinguish one emotion from another and improve his emotional granularity.

Like most students of psychology, I had read that each emotion is supposed to have a distinct pattern of physical changes, roughly like a fingerprint. Each time you grasp a doorknob, the fingerprints that you leave behind may vary depending on the firmness of your grip, how slippery the surface is, or how warm and pliable your skin is at that moment. Nevertheless, your fingerprints look similar enough each time to identify you uniquely. The fingerprint of an emotion is likewise assumed to be similar enough from one instance to the next, and in one person to the next, regardless of age, sex, personality, or culture. In a laboratory, scientists should be able to tell whether someone is sad or happy or anxious just by looking at physical measurements of a person’s face, body, and brain.

I felt confident that these emotion fingerprints could provide the objective criteria I needed to measure emotion. If the scientific literature was correct, then assessing people’s emotional accuracy would be a breeze. But things did not turn out quite as I expected.

…

According to the classical view of emotion, our faces hold the key to assessing emotions objectively and accurately. A primary inspiration for this idea is Charles Darwin’s book The Expression of the Emotions in Man and Animals, where he claimed that emotions and their expressions were an ancient part of universal human nature. All people, everywhere in the world, are said to exhibit and recognize facial expressions of emotion without any training whatsoever.³

So, I thought that my lab should be able to measure facial movements, assess our test subjects’ true emotional state, compare it to their verbal reports of emotion, and calculate their accuracy. If subjects made a pouting expression in the lab, for instance, but did not report feeling sad, we could train them to recognize the sadness they must be feeling. Case closed.

The human face is laced with forty-two small muscles on each side. The facial movements that we see each other make every day—winks and blinks, smirks and grimaces, raised and wrinkled brows—occur when combinations of facial muscles contract and relax, causing connective tissue and skin to move. Even when your face seems completely still to the naked eye, your muscles are still contracting and relaxing.⁴

Figure 1-1: Muscles of the human face

According to the classical view, each emotion is displayed on the face as a particular pattern of movements—a facial expression. When you’re happy, you’re supposed to smile. When you’re angry, you’re supposed to furrow your brow. These movements are said to be part of the fingerprint of their respective emotions.

Back in the 1960s, the psychologist Silvan S. Tomkins and his protégés Carroll E. Izard and Paul Ekman decided to test this in the lab. They created sets of meticulously posed photographs, such as those in figure 1-2, to represent six so-called basic emotions they believed had biological fingerprints: anger, fear, disgust, surprise, sadness, and happiness. These photos, which featured actors who were carefully coached, were supposed to be the clearest examples of facial expressions for these emotions. (They might look exaggerated or artificial to you, but they were designed this way on purpose, because Tomkins believed they gave the strongest, clearest signals for emotion.)⁵

Figure 1-2: Some facial photographs from basic emotion method studies

Using posed photos like these, Tomkins and his crew applied an experimental technique to study how well people recognize emotional expressions, or, more precisely, how well they perceive facial movements as expressions of emotion. Hundreds of published experiments have used this method, and it’s still considered the gold standard today. A test subject is given a photograph and a set of emotion words, as in figure 1-3.

Figure 1-3: Basic emotion method: picking a word to match the face

The subject then chooses the word that best matches the face. In this case, the intended word is Surprise. Or, using a slightly different setup, a test subject is given two posed photos and a brief story, as in figure 1-4, and then picks which face best matches the story. In this case, the intended face is on the right.⁶

Figure 1-4: Basic emotion method: picking a face to match the story

This research technique—let’s call it the basic emotion method—revolutionized the scientific study of what Tomkins’s group called emotion recognition. Using this method, scientists showed that people from around the world could consistently match the same emotion words (translated into the local language) to posed faces. In one famous study, Ekman and his colleagues traveled to Papua New Guinea and ran experiments with a local population, the Fore people, who had little contact with the Western world. Even this remote tribe could consistently match the faces to the expected emotion words and stories. In later years, scientists ran similar studies in many other countries such as Japan and Korea. In each case, subjects easily matched the posed scowls, pouts, smiles, and so on to the provided emotion words or stories.⁷

From this evidence, scientists concluded that emotion recognition is universal: no matter where you are born or grow up, you should be able to recognize American-style facial expressions like those in the photos. The only way expressions could be universally recognized, the reasoning went, is if they are universally produced: thus, facial expressions must be reliable, diagnostic fingerprints of emotion.⁸

Other scientists, however, worried that the basic emotion method was too indirect and subjective to reveal emotion fingerprints because it involves human judgment. A more objective technique, called facial electromyography (EMG), removes human perceivers altogether. Facial EMG places electrodes on the surface of the skin to detect the electrical signals that make facial muscles move. It precisely identifies the parts of the face as they move, how much, and how often. In a typical study, test subjects wear electrodes over their eyebrows, forehead, cheeks, and jaw as they view films or photos, or as they remember or imagine situations, to evoke a variety of emotions. Scientists record the electrical changes in muscle activity and calculate the degree of movement in each muscle during each emotion. If people move the same facial muscles in the same pattern each time they experience a given emotion—scowling in anger, smiling in happiness, pouting in sadness, and so on—and only when they experience that emotion, then the movements might be a fingerprint.⁹

As it turns out, facial EMG presents a serious challenge to the classical view of emotion. In study after study, the muscle movements do not reliably indicate when someone is angry, sad, or fearful; they don’t form predictable fingerprints for each emotion. At best, facial EMG reveals that these movements distinguish pleasant versus unpleasant feeling. Even more damning, the facial movements recorded in these studies do not reliably match the posed photos created for the basic emotion method.¹⁰

Figure 1-5: Facial electromyography

Let’s take a moment and consider the implications of these findings. Hundreds of experiments have shown that people worldwide can match emotion words to so-called expressions of emotion, posed by actors who aren’t actually feeling those emotions. However, those expressions can’t be consistently and specifically detected by objective measures of facial muscle movements when people are actually feeling emotion. We all move our facial muscles all the time, of course, and when we look at each other, we effortlessly see emotion in some of these movements. Nevertheless, from a purely objective standpoint, when scientists measure just the muscle movements themselves, those movements do not conform to the photographs.

It’s conceivable that facial EMG is too limited to capture all the meaningful actions in a face during an emotional experience. A scientist can place about six electrodes on each side of the face before a test subject starts to feel uncomfortable, too few to capture all forty-two facial muscles meaningfully. So scientists also employ an alternative technique called facial action coding (FACS), in which trained observers laboriously classify a subject’s individual facial movements as they occur. It’s less objective than facial EMG, since it relies on human perceivers, but presumably more objective than matching words to posed faces in the basic emotion method. Nevertheless, the movements observed during facial action coding also don’t consistently match the posed photos.¹¹

These same inconsistencies show up in infants. If facial expressions are universal, then babies should be even more likely than adults to express anger with a scowl and sadness with a pout, because they’re too young to learn rules of social appropriateness. And yet when scientists observe infants in situations that should evoke emotion, the infants do not make the expected expressions. For example, the developmental psychologists Linda A. Camras and Harriet Oster and their colleagues videotaped babies from various cultures, employing a growling gorilla toy to startle them (to induce fear) or restraining their arm (to induce anger). Camras and Oster found, using FACS, that the range of babies’ facial movements in the two situations was indistinguishable. Nevertheless, when adults watched these videos, they somehow identified the infants in the gorilla film as afraid and infants in the arm restraint film as angry, even when Camras and Oster blanked out the babies’ faces electronically! The adults were distinguishing fear from anger based on the context, without seeing facial movements at all.¹²

Don’t get me wrong: newborns and young infants move their faces in meaningful ways. They make many distinctive facial movements when the situation implies that they might be interested or puzzled, or when they feel distress in response to pain or distaste in response to offending smells and tastes. But newborns don’t show differentiated, adult-like expressions like the photographs from the basic emotion method.¹³

Other scientists also have demonstrated, as Camras and Oster did, that you take tremendous information from the surrounding context. They graft photographs of faces and bodies that don’t belong together, like an angry scowling face attached to a body that’s holding a dirty diaper, and their test subjects nearly always identify the emotion appropriate to the body, not the face—in this case, disgust rather than anger. Faces are constantly moving, and your brain relies on many different factors at once—body posture, voice, the overall situation, your lifetime of experience—to figure out which movements are meaningful and what they mean.¹⁴

When it comes to emotion, a face doesn’t speak for itself. In fact, the poses of the basic emotion method were not discovered by observing faces in the real world. Scientists stipulated those facial poses, inspired by Darwin’s book, and asked actors to portray them. And now these faces are simply assumed to be the universal expressions of emotion.¹⁵

But they aren’t universal. To further demonstrate this, my lab conducted a study using photos from a group of emotion experts—accomplished actors. The photos came from the book In Character: Actors Acting, in which actors portray emotions by posing their faces to match written scenarios. We divided our U.S. test subjects into three groups. The first group read only the scenarios, for example, He just witnessed a shooting on his quiet, tree-shaded block in Brooklyn. A second group saw only the facial configurations, such as Martin Landau’s pose for the shooting scenario (figure 1-6, center). A third group saw the scenarios and the faces. In each case, we handed subjects a short list of emotion words to categorize whatever emotion they saw.¹⁶

For the shooting scenario I just mentioned, 66 percent of subjects who read the scenario alone or with Landau’s face rated the scenario as a fearful situation. But for subjects who saw Landau’s face alone, devoid of context, only 38 percent of them rated it as fear and 56 percent rated it as surprise. (Figure 1-6 compares Landau’s facial configuration to basic emotion method photos for fear and surprise. Does Landau look afraid or surprised? Or both?)

Figure 1-6: Actor Martin Landau (center) flanked by basic emotion method faces for fear (left) and surprise (right)

Other actors’ poses for fear were strikingly different from Landau’s. In one case, the actress Melissa Leo portrayed fear for the scenario: She is trying to decide if she should tell her husband about a rumor going around that she is gay before he hears it from someone else. Her mouth is closed and downturned, and her brow is slightly knitted. Nearly three-quarters of our test subjects who saw her face alone rated it as sad, but when presented with the scenario, 70 percent of subjects rated her face as displaying fear.¹⁷

This sort of variation held true for every emotion that we studied. An emotion like Fear does not have a single expression but a diverse population of facial movements that vary from one situation to the next.* (Think about it: When is the last time an actor won an Academy Award for pouting when sad?)

This may seem obvious once you pause to consider your own emotional experiences. When you experience an emotion such as fear, you might move your face in a variety of ways. While cowering in your seat at a horror movie, you might close your eyes or cover them with your hands. If you’re uncertain whether a person directly in front of you could harm you, you might narrow your eyes to see the person’s face better. If danger is potentially lurking around the next corner, your eyes might widen to improve your peripheral vision. Fear takes no single physical form. Variation is the norm. Likewise, happiness, sadness, anger, and every other emotion you know is a diverse category, with widely varying facial movements.¹⁸

If facial movements have so much variation within an emotion category like Fear, you might wonder why we find it so natural to believe that a wide-eyed face is the universal fear expression. The answer is that it’s a stereotype, a symbol that fits a well-known theme for Fear within our culture. Preschools teach these stereotypes to children: People who scowl are angry. People who pout are sad. They are cultural shorthands or conventions. You see them in cartoons, in advertisements, in the faces of dolls, in emojis—in an endless array of imagery and iconography. Textbooks teach these stereotypes to psychology students. Therapists teach them to their patients. The media spreads them widely throughout the Western world. Now, wait just a minute, you might be thinking. "Is she saying that our culture has created these expressions, and we all have learned them?" Well . . . yes. And the classical view perpetuates these stereotypes as if they are authentic fingerprints of emotion.

To be sure, faces are instruments of social communication. Some facial movements have meaning, but others do not, and right now, we know precious little about how people figure out which is which, other than that context is somehow crucial (body language, social situation, cultural expectation, etc.). When facial movements do convey a psychological message—say, raising an eyebrow—we don’t know if the message is always emotional, or even if its meaning is the same each time. If we put all the scientific evidence together, we cannot claim, with any reasonable certainty, that each emotion has a diagnostic facial expression.¹⁹

…

In my search for unique fingerprints of emotion, I clearly needed a more reliable source than the human face, so next I looked to the human body. Perhaps some telling changes in heart rate, blood pressure, and other body functions would provide the necessary fingerprints to teach people to recognize their emotions more accurately.

Some of the strongest experimental support for bodily fingerprints comes from a famous study by Paul Ekman, the psychologist Robert W. Levenson, and their colleague Wallace V. Friesen, published in the journal Science in 1983. They hooked up test subjects to machines to measure changes in the autonomic nervous system: variations in heart rate, temperature, and skin conductance (a measure of sweat). They also measured variations in arm tension, rooted in the skeletomotor nervous system. They then used an experimental technique to evoke anger, sadness, fear, disgust, surprise, and happiness, and observed the physical changes during each emotion. After analyzing the data, Ekman and his colleagues concluded that they had meas­ured clear and consistent changes in these bodily responses, relating them to particular emotions. This study seemingly established objective, biological fingerprints in the body for each of the studied emotions, and today it remains a classic in the scientific literature.²⁰

The famous 1983 study evoked emotion in a curious way—by having test subjects make and hold a facial pose from the basic emotion method. To evoke sadness, for example, a subject would frown for ten seconds. To evoke anger, a subject would scowl. While face-posing, subjects could use a mirror and were coached by Ekman himself to move particular facial muscles.²¹

The idea that a posed, so-called facial expression can trigger an emotional state is known as the facial feedback hypothesis. Allegedly, contorting your face into a particular configuration causes the specific physiological changes associated with that emotion in your body. Try it yourself. Knit your brows and pout for ten seconds—do you feel sad? Smile broadly. Do you feel happier? The facial feedback hypothesis is highly controversial—there is wide disagreement on whether a full-blown emotional experience can be evoked this way.²²

The 1983 study did, in fact, observe bodily changes as people posed the required facial configurations. This is a remarkable finding: just posing a particular facial configuration changed the test subjects’ peripheral nervous system activity, even while they were comfortably motionless in a chair. Their fingertips were warmer when posing a scowl (anger pose). Their heartbeats were faster when posing scowls, wide-eyed startle (fear pose), and pouts (sad pose) when compared to the poses for happiness, surprise, and disgust. The remaining two measures, skin conductance and arm tension, did not distinguish one facial configuration from another.²³

Even so, you must take some additional steps before you can claim that you’ve found a bodily fingerprint for an emotion. For one thing, you must show that the response during one emotion, say, anger, is different from that of other emotions—that is, it’s specific to instances of anger. Here, the 1983 study starts having some difficulty. It showed some specificity for anger but not for the other emotions tested. That means the bodily responses for different emotions were too similar to be distinct fingerprints.

In addition, you must show that no other explanations can account for your results. Then, and only then, can you claim to have found physical fingerprints for anger, sadness, and the rest. The 1983 study is, for this reason, subject to an alternative explanation, because the test subjects were given instructions for how to pose their faces. Western subjects could conceivably identify most of the target emotions from these instructions. This understanding can actually produce the heart rate and other physical changes Ekman and colleagues observed, a fact that was unknown when these studies were conducted. This alternative explanation is borne out by their later experiment with an Indonesian tribe, the Minangkabau of West Sumatra. These volunteers had less understanding of Western emotions and did not show the same physical changes as Western test subjects; they also reported feeling the expected emotion much less frequently than the Western subjects did.²⁴

Other subsequent research has evoked emotions using a variety of different methods but has not replicated the original physiological differences observed in the 1983 paper. Quite a few studies employ horror movies, tearful chick flicks, and other evocative material to bring on particular emotions, while scientists measure subjects’ heart rate, respiration, and other bodily functions. Many such studies found great variability in physical measurements, meaning no clear pattern of bodily changes that distinguished emotions. In other studies, scientists did find distinguishing patterns, but different studies often found different patterns, even when using exactly the same film clips. In other words, when studies distinguished anger from sadness from fear, they did not always replicate one another, implying that the instances of anger, sadness, and fear cultivated in one study were different from those cultivated in another.²⁵

When faced with a large collection of diverse experiments like this, it’s hard to extract a consistent story. Fortunately, scientists have a technique to analyze all the data together and reach a unified conclusion. It’s called a meta-analysis. Scientists comb through large numbers of experiments conducted by different researchers, combining their results statistically. As a simple example, suppose you wanted to check if increased heart rate is part of the bodily fingerprint of happiness. Rather than run your own experiment, you could do a meta-analysis of other experiments that meas­ured heart rate during happiness, even incidentally (e.g., the study could be about the relationship between sex and heart attacks and have nothing centrally to do with emotion). You would search for all the relevant scientific papers, collect the relevant statistics from them, and analyze them en masse to test the hypothesis.

Where emotions and the autonomic nervous system are concerned, four significant meta-analyses have been conducted in the last two decades, the largest of which covered more than 220 physiology studies and nearly 22,000 test subjects. None of these four meta-analyses found consistent and specific emotion fingerprints in the body. Instead, the body’s orchestra of internal organs can play many different symphonies during happiness, fear, and the rest.²⁶

You can see this variation easily in an experimental procedure used by laboratories around the world, where test subjects perform a difficult task such as counting backward by thirteen as fast as possible, or speaking about a polarizing topic like abortion or religion, while being ridiculed. As they struggle, the experimenter berates them for poor performance, making critical and even insulting remarks. Do all the test subjects get angry? No, they don’t. More importantly, those who do feel angry show different patterns of bodily changes. Some people fume in anger, but some cry. Others become quiet and cunning. Still others just withdraw. Each behavior (fuming, crying, planning, withdrawing) is supported by a different physiological pattern in the body, a detail long known by physiologists who study the body for its own sake. Even small changes in body posture, like lying back versus leaning forward with arms crossed, can completely alter an angry person’s physiological response.²⁷

When I address audiences at conferences and present these meta-analyses, some people become incredulous: Are you saying that in a frustrating, humiliating situation, not everyone will get angry so that their blood boils and their palms sweat and their cheeks flush? And my answer is yes, that is exactly what I am saying. As a matter of fact, earlier in my career, when I was giving my first talks about these ideas, you could see variations in anger firsthand in audience members who really didn’t like the evidence. Sometimes they would shift around in their seats. Other times they shook their head in a silent no. Once a colleague yelled at me while his face turned red and he stabbed his finger in the air. Another colleague asked me, in a sympathetic tone, if I had ever felt real fear, because if I’d ever been seriously harmed, I would never be suggesting such a preposterous idea. Yet another colleague said he would tell my brother-in-law (a sociologist of his acquaintance) that I was damaging the science of emotion. My favorite example involved a much more senior colleague, built like a linebacker and towering a foot above me, who cocked his fist and offered to punch me in the face to demonstrate what real anger looks like. (I smiled and thanked him for the thoughtful offer.) In these examples, my colleagues demonstrated the variability of anger far more handily than my presentation did.

What does it mean that four meta-analyses, summarizing hundreds of experiments, revealed no consistent, specific fingerprints in the autonomic nervous system for different emotions? It doesn’t mean that emotions are an illusion, or that bodily responses are random. It means that on different occasions, in different contexts, in different studies, within the same individual and across different individuals, the same emotion category involves different bodily responses. Variation, not uniformity, is the norm. These results are consistent with what physiologists have known for over fifty years: different behaviors have different patterns of heart rate, breathing, and so on to support their unique movements.²⁸

Despite tremendous time and investment, research has not revealed a consistent bodily fingerprint for even a single emotion.

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My first two attempts to find objective fingerprints of emotion—in the face and body—had led me smack into a closed door. But as they say, when a door closes, sometimes a window opens. My window was the unexpected realization that an emotion is not a thing but a category of instances, and any emotion category has tremendous variety. Anger, for example, varies far more than the classical view of emotion predicts or can explain. When you’re angry at someone, do you shout and swear or do you seethe quietly? Do you tease back in reproach? How about widening your eyes and raising your eyebrows? During these times, your blood pressure might go up or down or stay the same. You might feel your heart beating in your chest, or not. Your hands might become clammy, or they might remain dry . . . whatever best prepares your body for action in that situation.

How does your brain create and keep track of all these diverse angers? How does it know which one fits the situation best? If I asked how you felt in each of these situations, would you give a detailed answer like aggravated, irritated, outraged, or vengeful automatically with little effort? Or would you answer angry in each case, or simply, I feel bad? How do you even know the answer? These are mysteries that the classical view of emotion doesn’t acknowledge.

I didn’t know it at the time, but as I considered emotion categories in all their diversity, I was unwittingly applying a standard way of thinking in biology called population thinking, which was proposed by Darwin. A category, such as a species of animal, is a population of unique members who vary from one another, with no fingerprint at their core. The category can be described at the group level only in abstract, statistical terms. Just as no American family consists of 3.13 people, no instance of anger must include an average anger pattern (should we be able to identify one). Nor will any instance necessarily resemble the elusive fingerprint of anger. What we have been calling a fingerprint might just be a stereotype.²⁹

Once I adopted a mindset of population thinking, my whole landscape shifted, scientifically speaking. I began to see variation not as error but as normal and even desirable. I continued my quest for an objective way to distinguish one emotion from another, but it wasn’t quite the same quest anymore. With growing skepticism, I had only one place left to look for fingerprints. It was time to turn to the brain.*

Scientists have long studied people with brain damage (brain lesions) to try to locate an emotion in a specific area of the brain. If someone with a lesion in a particular area of the brain has difficulty experiencing or perceiving a particular emotion, and only that emotion, then this would be considered evidence that the emotion specifically depends on the neurons in that region. It’s a bit like finding out which circuit breakers in your house control which parts of your electrical system. Initially, all breakers are on and your house runs normally. When you shut off one breaker (giving your electrical system a lesion of sorts) and observe that your kitchen lights no longer function, you’ve discovered a purpose of the breaker.

The search for fear in the brain is an instructive example because for many years, scientists have considered it a textbook case of localizing emotion to a single brain area—namely, the amygdala, a group of nuclei found deep in the brain’s temporal lobe.* The amygdala was first linked to fear in the 1930s when two scientists, Heinrich Klüver and Paul C. Bucy, removed the temporal lobes of rhesus monkeys. Lacking an amygdala, these monkeys approached objects and animals that would normally frighten them, like snakes, unfamiliar monkeys, or others that they’d avoided before the surgery, without hesitation. Klüver and Bucy attributed these deficits to an absence of fear.³⁰

Not long afterward, other scientists began studying humans with amygdala damage to see if those patients continued to experience and perceive fear. The most intensively studied case is a woman known as SM, afflicted with a genetic disease that gradually obliterates the amygdala during childhood and adolescence, called Urbach-Wiethe disease. Overall, SM was (and still is) mentally healthy and of normal intelligence, but her relationship to fear seemed quite unusual in laboratory tests. Scientists showed her horror movies like The Shining and The Silence of the Lambs, exposed her to live snakes and spiders, and even took her through a haunted house, but she reported no strong feelings of fear. When SM was shown wide-eyed facial configurations from the basic emotion method’s set of photos, she had difficulty identifying them as fearful. SM experienced and perceived other emotions normally.³¹

Scientists tried unsuccessfully to teach SM to feel fear, using a procedure commonly called fear learning. They showed her a picture and then immediately blasted a boat horn at one hundred decibels to startle her. This sound was meant to trigger SM’s fear response if she had one. At the same time, they measured SM’s skin conductance, which many scientists believe to be a measure of fear and is related to amygdala activity. After many repetitions of the picture followed by the horn blast, they showed SM the picture alone and measured her response. People with intact amygdalae would have learned to associate the picture with the startling sound, so if just shown the picture, their brain would predict the horn blast and their skin conductance would jump. But no matter how many times scientists paired the picture and the loud sound, SM’s skin conductance didn’t increase when