The Hidden Brain: How Our Unconscious Minds Elect Presidents, Control Markets, Wage Wars, and Save Our Lives

by Shankar Vedantam

  It was an unlikely scenario, to be sure, but not categorically impossible. How do most of us tell the difference between a surly waiter and a homicidal maniac? We don’t conduct investigations, we don’t march into restaurant kitchens to see what’s being sprinkled on our food. Everyday life depends on our ability to make a series of unconscious assumptions, and one of them is to trust that the food served to us at a clean restaurant is good food.

  Our hidden brain makes rapid judgments about the likelihood of various scenarios, and dismisses the unlikely ones before they can even appear over the horizon of conscious thinking. This is why most of us do not suspect the careless driver who rear-ends our car of trying to kill us, or believe that the medical secretary who asks for our Social Security number is part of an identity-theft crime syndicate. In a world where we have nothing to go on but our rational minds, the simplest things can paralyze us because it can take huge amounts of time for our conscious brain to think about every scenario deliberately. If we didn’t have our hidden brain to weed through thousands of scenarios and to guide our attention to the most pertinent questions, we would quickly become overwhelmed, because bad things can potentially happen to us in every conceivable situation. Everyday life requires us to suspend rationality, to be mindless about countless risks.

  There is no cure as yet for disorders such as schizophrenia, autism, or frontotemporal dementia. Patients with Wendy’s disorder who are in otherwise excellent health can easily outlive their caregivers, which worries Brian McNamara endlessly. He has started to work again, and has enrolled Wendy in a day program to practice her social and physical skills.

  On a recent visit I paid to the McNamaras, Wendy greeted me at the door with a beaming smile and the single word “Cute!” Brian and Wendy and Evelyn Sommers, who was visiting, took me back to a kitchen table overlooking a yard, where Wendy used to grow plants. I asked Wendy if she had green thumbs, and she said, “Maybe so.” A moment later, she added, “Cute!” I realized the word was not a judgment but a tic.

  Brian showed me a couple of watercolors Wendy had painted many years ago; one showed a cottage snuggled among trees, bathed in dappled sunlight. It was the work of a sure hand and a keen eye. When Brian sets Wendy before paint and brushes now, all she manages are broad strokes one above the other, like a child’s rainbow. Inasmuch as Wendy is more sensitive than ever to form and line and color, she no longer has access to the unconscious skills that all artists must possess—the ability to grasp the feeling of a picture and the drive to express that feeling.

  Wendy abruptly interrupted our conversation about painting to inform me that I had a hole in my right earlobe. I told her this came as news. (I later found a deep declivity in my earlobes that I had not noticed before.) She asked me to turn my head so she could inspect my other ear. When I obliged, she told me my ears were kinky, and small for my head. I had expected Wendy to say and do socially inappropriate things. Her pleasant smile and cheerful demeanor robbed her comments of any sting; I found myself drawn to her authenticity. I told her that narcissistic people might be willing to pay good money to sit before her and have her observe things about them that no one had noticed before. “Maybe so,” she said.

  There were some pinecones on the table, and Wendy played with them, passing one hand and then the other over the ridges. She showed me how the ridges were open at the top and bottom of the pinecone, but closed at the middle. Brian asked her how the pinecone felt to her, and she said, again, that the ridges were open at the top and bottom, and pressed in at the middle—she had no access to how the pinecone felt. Wendy rose and wandered over to a bowl of potpourri and symmetrically ran her hands over a number of objects.

  Although she is in the thrall of compulsions, Wendy does not have the feelings typically associated with satisfying or denying compulsions. If there is an open bottle of wine available, Wendy can drain it like water, but if she asks for wine and Brian tells her no bottle is open, she feels nothing.

  As Brian and Evelyn and I talked, Wendy wandered in and out, sometimes hanging on the periphery of our conversation, and other times walking out of the room. At one point, with Wendy back at the kitchen table, we talked about the visit to France. Evelyn reminded Wendy about her late partner, Larry.

  “You remember Larry, my Larry, don’t you?” Evelyn asked.

  “Maybe so,” Wendy replied with a bright smile.

  “You know he died?”

  “Cute!”

  Wendy loaded dishes into the dishwasher, slowly exploring the ridges and contours of every plate and cup. She washed her hands with soap and water several times, and lingered over a towel, her fingers moving over the texture of the cloth like a blind person.

  She returned to make a comment about my shoes. She asked if she could see the underside of my left sole. I lifted my shoe, and she smiled happily. She then inspected the sole of her sister’s shoe.

  Wendy did not seem offended as Brian and Evelyn talked about frontotemporal dementia. She acknowledged that doctors had given her a diagnosis, but she spoke as one given a doubtful tip about a racehorse. When I asked her if she disagreed with the diagnosis, she smiled pleasantly and said, “Maybe so.” One reason frontotemporal dementia is much harder on caregivers than on patients is that victims lack awareness of what they have lost.

  Wendy never gets angry. It has been years since she shed a tear. She can watch suspenseful shows on television with detachment, observing sound and light and color while remaining untouched by the story. Day-to-day life around her can be lighthearted, even funny. Wendy’s comments about my ears made everyone laugh in the same way intensely honest observations from a child can make grown-ups laugh. Being around Wendy was like watching a comedian relate a tragedy—all laughs, cracks, and quips. The sadness lay in what was never said.

  CHAPTER 4

  The Infant’s Stare, Macaca, and Racist Seniors

  The Life Cycle of Bias

  When my daughter was a few days old, I prowled back and forth in front of her as she lay swaddled in her bassinet. She watched. As I circled the room, she kept her eyes fixed on mine until the rim of the bassinet obscured her vision. The moment I reappeared, she homed in again. I wasn’t being a proud father; I was conducting an experiment. If you know anything about infants, the fact that my daughter tracked my eyes as I walked around her room will not strike you as surprising. Indeed, her behavior will seem so commonplace that you might wonder why I mention it—or put it down to the usual vanity of parents who insist that ordinary things about their children are somehow extraordinary.

  The fact that infants are so adept at tracking their parents as they move about is actually quite extraordinary. It is also one of the earliest visible examples of the hidden brain at work. Without thought or effort, my daughter was doing something that has stumped supercomputers for years. Consider the problem from an engineering perspective. Let’s say you want to design an intelligent camera to spot a pair of eyes. If the face is in front of you, you would teach the camera to locate two blobs that are symmetrically positioned on either side of the nose (once you teach the camera to recognize a nose). But faces are usually not in front of us. Most of the time, they are off to one side or another, displaced in any one of a thousand possible angles. Sometimes all we can see is a single eye. If a face should vanish and reappear, our camera would have to not only recognize that a face (and not a pumpkin) had come into view, but calculate at what angle the face was being presented. If the camera worked through trial and error, it might produce thousands of errors before it found the right answer. The reason my daughter tracked my eyes effortlessly is that she arrived in this world with the innate ability to distinguish faces and eyes from other objects. Brightly colored toys could capture her attention, but they were only interesting things in a world that awaited exploration. My face and eyes, on the other hand, were already meaningful.

  In the long journey of learning and survival that lay before her, my daughter’s ability to lock eyes with me was a cr
ucial step. The faces of her parents, after all, were not just objects in an object-cluttered world; they were her link to food and water, to comfort, protection, and security. Babies the world over face radically different challenges for survival, but all the problems have the same solution—the loving attention of parents.

  The hidden brain is designed to preferentially recognize faces over other objects. Across generations, infants who formed a bond by locking on to the eyes of their parents were more likely to survive than infants who found trees or dogs or rocks more interesting. Italian researchers once showed that newborns who were just a day old preferred geometric shapes that resembled a human face over shapes that did not. It takes barely five hours of face-to-face time for an infant to develop a preferential attachment to her mother’s face over that of a stranger. This is extraordinary when you consider how similar faces are to one another, and how limited and helpless newborn infants are in virtually every other domain of physical and mental performance.

  Our preferential ability to recognize faces—and certain faces, in particular—makes the human brain very different from a computer. My daughter’s brain was designed to be biased, to pay attention to faces at the expense of other objects, and to some faces at the expense of others. You can see why such a bias is useful. As infants, it allows us to latch on to our parents. As children, it helps us recognize a friend across a crowded playground. As young adults searching for mates, it gives us the ability to make exquisitely sensitive distinctions in matters of beauty and attractiveness. Throughout life, faces are our guides to the feelings and predispositions of those around us; facial expressions let us know when our neighbor is upset; they tell us whether the cute sophomore is interested in going out on a date; they warn us about people who intend to do us harm. If you were designing a brain from scratch, you would want to bias it to pay attention to faces over other objects.

  In recent years, scientists have found an area in the brain—called the fusiform face area—that specializes in recognizing human faces. It is activated when we see a face, and also when we remember a face. Brain imaging studies show the fusiform face area is activated only by human faces (and not by other objects or by faces of other animals) and is sensitive to faces presented in full view, in profile, and as cartoons. This part of the hidden brain even lights up in response to two-tone pictures that provide minuscule amounts of information—and that require us to mentally “fill in” a picture in order to recognize a face.

  The unconscious influence of the fusiform face area explains why people regularly see human faces in random patterns of nature. Shortly after Iraqi dictator Saddam Hussein was executed in 2006, for example, many people in Iraq swore they saw the dictator’s face imprinted on the moon. When I looked at a photograph of that moon over Iraq, it took me a few seconds to spot Saddam Hussein’s visage, but there it was, all right—his eyes, nose, even his mustache. The coincidence said less about the supernatural than about the way the hidden brain has a systematic bias to recognize anything that looks like a face. There is a good reason people in Iraq, rather than people in Kazakhstan, noticed the Saddam-like image. The Iraqis had seen the dictator’s face thousands of times. Their hidden brains had learned to preferentially recognize that face—even in the craters of the moon.

  Researchers once found that people shown a Lexus whose front grille was turned up in the form of a human smile (with the headlights serving as eyes) liked the car better than when the ends of the grille were turned down in the shape of a frown. As usual, volunteers in the study were not aware that a subtle face recognition bias had influenced their judgment. Many people also show strong, automatic, and unthinking preferences for animals that have humanlike features. Beluga whales and dolphins, with their smooth heads, cherubic eyes, and mouths shaped in humanlike smiles, are more appealing to us than sea lampreys and octopi. Two dark splotches of fur cause giant pandas to look like they have large eyes, and the hidden brain associates large eyes with babies. It is not surprising that the panda has become a global symbol for conservation. (Zoos have to take great care to keep pandas, which can be dangerous, away from people—because the hidden brains of zoo visitors tell them that pandas are cute and cuddly.)

  Cartoons routinely show animals whose faces have been anthropomorphized—bears and tigers in children’s cartoons not only talk a human language, but have their features altered to look humanlike. When we see a mouse that looks like a real mouse and a mouse whose features have been altered to look like a human, our hidden brain places a finger on our internal scale and causes us to find the anthropomorphized mouse more pleasing. We may consciously know that mice are vermin, carriers of deadly diseases, and opportunistic scavengers. But when you widen and move a mouse’s eyes from the sides of its head to the front, give it a high-wattage smile, and conceal its grubby paws in yellow boots and white gloves, the hidden brain fools us into thinking this mouse is an endearing creature. You don’t need a scientific experiment to prove this. Just run to the nearest encyclopedia and look up “Disney, Walt.”

  I have spent a fair amount of time on the brain’s affinity for faces to show how pervasive the effects of this simple bias can be. But this seemingly innocuous bias can also have not-so-benign consequences. Experiments show that our unthinking tendency to find baby features adorable biases us to trust adults who happen to have large eyes and cherubic features over adults who do not look childlike—even when the adults with childlike features are liars.

  The brain’s bias for familiar faces also makes it easier for us to recognize those from our own ethnic group than members of less familiar ethnic groups. Our hidden brains arrive in this world with the instant ability to orient themselves in any culture. A Chinese infant born in China will form a preferential attachment to Chinese faces. Through countless encounters with cooing relatives, doting parents, and smiling strangers, most of whom are Chinese, the baby learns to make extremely fine distinctions between Chinese faces. People who have little or no contact with Chinese people, by contrast, have a harder time making fine distinctions between Chinese faces, especially in situations that call for rapid judgment.

  When a Chinese person is asked to spot the difference between two Chinese faces, the mental work is automatic—such challenges have been encountered so many times that the hidden brain has mastered rules to solve the problem without input from the conscious brain. When someone is asked to make distinctions between two people from an unfamiliar ethnic group, the challenge is met by the conscious brain, because it is novel. With effort, the conscious brain of a novice can arrive at the same conclusion as the hidden brain of an expert, but it takes a second longer. Someone who grows up in rural China and is transported to predominantly white Iowa will think most Iowans look alike. But the playing field isn’t level. Patterns of global cultural consumption—Hollywood movies and the spread of American popular culture—mean that people in Ethiopia, Korea, and China are far more likely to have repeated exposure to Caucasian faces than the other way around.

  I occasionally get mistaken for other Indian Americans at work. It upsets me, of course, and the moment my colleagues recognize the error, they are mortified. I feel that my Indian American colleagues and I look very different, but that is because over a matter of decades I have come into close contact with tens of thousands of Indians and Indian Americans. My exposure to so many South Asian faces has taught my hidden brain to make rapid and fine distinctions among such faces. Mixing up faces of people belonging to unfamiliar ethnic groups does not make us bad people, but it does say a lot about whom we are familiar and unfamiliar with. We are most likely to mix up people when we are stressed or distracted: The conscious mind has its hands full, and the hidden brain leaps to the wrong conclusion.

  If you believe human behavior is mostly driven by conscious thinking, such errors can produce grave misunderstandings. In 2006, African American Congresswoman Cynthia McKinney of Georgia got furious when a Capitol Hill police officer failed to recognize her. She walked aro
und a metal detector, as members of Congress are allowed to do, and when a white police officer pursued and challenged her, she struck him in the chest. The story line developed predictably from there: McKinney and several African American leaders said the incident was emblematic of racism in American society and of the extra vigilance that people of color endure at the hands of police. An NAACP leader said the officer had treated McKinney with “disrespect.” Conservative groups, meanwhile, lambasted McKinney for striking an officer. The following year, McKinney was defeated in her attempt to retain her seat in Congress.

  If you think about the incident with the hidden brain in mind, you can see how the police officer who failed to recognize McKinney might have been guilty of an unconscious race bias, in that he might have been less likely to make a similar error with a white congressman. Most congressional representatives are white men, and it’s a safe bet that most of the people authorized to walk around metal detectors on Capitol Hill are white men. Through sheer repetition, the hidden brains of Capitol Hill police officers will have learned to recognize the faces of white congressmen more or less automatically. Identifying congressional representatives who belong to a less familiar group—African American women—can take a second longer because the mental processing has to be carried out by the conscious brain. The officer most likely intended McKinney no disrespect, and she was wrong to strike him.