How 'The Hidden Brain' Does The Thinking For Us Science writer Shankar Vedantam says we often function on autopilot — without even knowing it. His new book, The Hidden Brain, explores how unconscious biases color our decisions even when we think we are acting rationally.

How 'The Hidden Brain' Does The Thinking For Us

How 'The Hidden Brain' Does The Thinking For Us

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Shankar Vedantam is a science writer for The Washington Post and a Nieman Fellow at Harvard University. Gary Knight hide caption

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Gary Knight

Shankar Vedantam is a science writer for The Washington Post and a Nieman Fellow at Harvard University.

Gary Knight

After making a silly mistake, it's not uncommon for a person to say, "Oops — I was on autopilot." In his new book, The Hidden Brain, science writer Shankar Vedantam explains how there's actually a lot of truth to that.

Our brains have two modes, he tells NPR's Steve Inkseep — conscious and unconscious, pilot and autopilot — and we are constantly switching back and forth between the two.

"The problem arises when we [switch] without our awareness," Vedantam says, "and the autopilot ends up flying the plane, when we should be flying the plane."

The autopilot mode can be useful when we're multitasking, but it can also lead us to make unsupported snap judgments about people in the world around us. Vedantam says that when we interact with people from different backgrounds in high-pressure situations, it's easy to rely — unconsciously — on heuristics.

'The Hidden Brain' book cover
The Hidden Brain
By Shankar Vedantam
Hardcover, 288 pages
Spiegel & Grau
List price: $26
Read An Excerpt

3-Year-Old Bigots?

Racial categorization begins at an extremely early age. Vedantam cites research from a day-care center in Montreal that found that children as young as 3 linked white faces with positive attributes and black faces with negative attributes.

"Now, these were children who are 3 years old," Vedantam says. "It is especially hard to call them bigots, or to suggest that they are explicitly racially biased or have animosity in their hearts."

Vedantam says the mind is hard-wired to "form associations between people and concepts." But he thinks that the links the children made between particular groups and particular concepts were not biologically based — those judgments came from culture and upbringing.

"We tend to think of the conscious messages that we give children as being the most powerful education that we can give them," Vedantam says — but the unconscious messages are actually far more influential.

He says that for every 50 times a year a teacher talks about tolerance, there are many hundreds of implicit messages of racial bias that children absorb through culture — whether it's television, books or the attitudes of the adults and kids around them.

"And it's these hidden associations that essentially determine what happens in the unconscious minds of these children," Vedantam says.

'Take Back The Controls'

In American society, colorblindness is often held up as the ideal. And though it's a worthy aspiration, Vedantam says it's a goal that isn't rooted in psychological reality.

"Our hidden brains will always recognize people's races, and they will do so from a very, very young age," Vedantam says. "The far better approach is to put race on the table, to ask [children] to unpack the associations that they are learning, to help us shape those associations in more effective ways."

Going back to the autopilot analogy, Vedantam says it's not a problem that the brain has an autopilot mode — as long as you are aware of when it is on. His book, The Hidden Brain, is about how to "take back the controls."

So if the human psyche is just a big constellation of conscious and unconscious cognition — which thoughts represent the real you?

"Most of us think of ourselves as being conscious, intentional, deliberate creatures," Vedantam says. "I know that I think of myself that way: I know why I like this movie star, or why I voted for this president, or why I prefer this political party to that."

But doing research for this book changed all that, Vedantam says.

"I have become, in some ways, much more humble about my views and much less certain about myself. And it may well be that the hidden brain is much more in charge of what we do than our conscious mind's intentions."

Excerpt: 'The Hidden Brain'

The Hidden Brain
The Hidden Brain
By Shankar Vedantam
Hardcover, 288 pages
Spiegel & Grau
List price: $26.00

The Siren's Call
Disasters and the Lure of Conformity

We have seen how unconscious bias plays a role in simple decisions such as whether to give a waitress an extra-large tip, or to buy a stock with a complicated ticker code. We have seen the effects of the hidden brain in professional settings and in the minds of young children. The remaining chapters of this book each focus on an important issue and examine the effects of unconscious bias in that domain. Subsequent chapters will examine the automatic biases of suicide terrorists, the role of unconscious racism in death penalty sentencing and in presidential elections, and the effects of bias on moral decision-making. This chapter focuses on the role of the hidden brain during disasters.

The Belle Isle bridge in Detroit was not designed with a psychology experiment in mind. But on an August night some years ago, it became a laboratory for the study of human nature. Being on a bridge is in some respects like being in an elevator or on a passenger plane. It's an experience so familiar that we barely register it as an experience at all. But when things go wrong, a bridge can quickly turn into something very different: a confined space where large numbers of people are surrounded by total strangers.

The nineteen cantilevered arches of the Belle Isle bridge span 2,356 feet. Two lanes of traffic run in each direction between Detroit and its favorite public park, the island of Belle Isle. Thirty feet below the cars, the currents of the Detroit River run swiftly toward Lake Erie. On a clear day with no traffic, a car going thirty-five miles an hour can cross the bridge in forty-five seconds. But such speed is inconceivable on summer nights, when traffic clogs the bridge in both directions. Hundreds of cars can be jammed together, inches separating one bumper from the next. Although most people don't think about it, the fact is from the moment they drive onto the bridge until the moment they get off, they are trapped.

The third Friday night in August 1995 was a typical summer night. Countless young people from Detroit came over the bridge to Belle Isle. Cars cruised around a portion of the island known as the strip. People rolled down their windows and drove slowly; the idea was to watch and be watched. Loud music blared from the cars. It was late. Midnight came and went. Somewhere in the crowd, a thirty-three year-old woman took a drag on a marijuana joint. Deletha Word was four feet eleven inches tall and weighed one hundred fifteen pounds. She had a dog by her side. Deletha was chatting with someone she had met at Belle Isle that evening. What were they talking about? Perhaps just the minutiae of everyday life. Deletha, who was known to her family as Lisa, worked at a grocery store. She was finishing a marketing degree, after which she hoped to pursue a career in fashion. She had a thirteen-year-old daughter.

A young man materialized from the darkness. A suitor. Martell Welch was six foot one and weighed nearly three hundred pounds, a former high school football player. As Deletha's acquaintance would later recount, the petite woman wasn't interested. But the nineteen year-old was insistent. He reached out and touched Deletha. She pulled back. Martell pressed forward. Words rang out. As he made himself more unpleasant—and more intimidating—Deletha could think of only one way to extricate herself. She jumped into her station wagon and drove off—her hurry so great that she forgot to take her dog. She headed for the bridge. By now, she was thoroughly rattled. When she looked into her rearview mirror, she saw that the hulk had jumped into his car and was coming after her. Deletha stepped on the gas, desperate to get some distance from her pursuer before they reached the bottleneck of the bridge.

Twenty-three-year-old Tiffany Alexander had been at a small gathering at a friend's place that evening. Detroit in August can be hot and sticky, and someone suggested a drive. Tiffany grabbed her cellphone and climbed into the back of a GMC Jimmy. There were two men and another woman in the car. The friends drove to Belle Isle and started a leisurely cruise around the island. They were about three-quarters of the way around when Tiffany, who was sitting behind the driver, saw something out of the corner of her eye. A Plymouth Reliant station wagon shot by. It was going fast, maybe twice the twenty-five-miles-per-hour speed limit. A moment later, another car whizzed past. It was a Chevy Monte Carlo.

By the time Tiffany and her friends reached the bridge, the car chase was over. Deletha and Martell had been brought to a stop by the traffic on the bridge; Martell had caught up with Deletha and had pulled up to her rear bumper. In her panic, Deletha threw the station wagon into reverse, and backed right into the Monte Carlo. There was a jarring bump. Before Deletha could move, Martell jumped out and raced over to the station wagon. There were three other young men in the car with Martell, and they got out, too. As the SUV Tiffany was in pulled alongside the two stationary cars, she saw a large man reach through the window of the Plymouth station wagon and grab hold of a small woman. Martell hauled Deletha up and out. Yanking her partially through the window, he flexed his fingers into a fist and hit her. Martell pinned her against the window frame, and pounded on her like a jackhammer. At the sight of the violence, Tiffany involuntarily slouched down in her seat. She couldn't see Deletha's face, but she could see Martell clearly. Deletha's body hung halfway out the window. Punch! . . . Punch! . . . Punch! . . . The young woman's body shuddered with the blows—Tiffany could not believe it was happening in plain view. Slowly Tiffany's car pulled away from the scene. All the way across the jammed bridge and for a good half mile afterward, Tiffany and her friends talked about the altercation. What could have prompted such violence? What would happen to the woman? Tiffany felt shaken up. She worried about the woman. But it never occurred to her to call the police on her cellphone. Dozens of people, after all, were at the scene—surely someone else would intervene. Behind Tiffany, other cars stopped around the station wagon and the Monte Carlo. Bystanders formed concentric circles of shock and horror. Martell's assault continued. His three friends—and a gaping crowd—looked on, and did nothing to stop him. Twenty-one-year-old Lehjuan Jones saw the football player drag the woman out of her car, strip off her pants, and swear that he was going to kill her. Three car lengths behind the Monte Carlo, a forty-year-old Detroit bus driver named Harvey Mayberry saw a young woman being dragged along the bridge by a young man. Another bystander, twenty-three-year-old Michael Sandford, saw Martell seize Deletha's hair in his fist. The woman struggled, her arms and legs flailing as Martell spun her around like a rag doll. Deletha was trying to find something to hold on to. Harvey Mayberry, the bus driver, saw Martell slam Deletha's head down onto the hood of his car while screaming about the damage the fender bender had inflicted on his vehicle. Blood covered Deletha's face. People watched, openmouthed. Harvey Mayberry felt paralyzed—it wasn't just Martell he was afraid of; he was afraid of the three young men who were with Martell. Raymont McGore, a dockworker who had come upon the scene, also felt paralyzed. If just one other person had stepped forward to help Deletha, the dockworker felt he might have jumped in, too. But no one in the growing circle of bystanders did anything. Martell hoisted Deletha into the air and proffered the naked woman to the crowd.

'Does anybody want some of this bitch?' he screamed. 'Because she has to pay for my car.'

Martell flung Deletha down onto the bridge and kicked her. She lay there, helpless, and the crowd gaped. Martell retrieved a tire iron and began to smash Deletha's station wagon; his friends helped him damage her car. All Deletha wanted was to get away. She woozily crossed over to the other side of the bridge, stumbling past stopped cars and wide-eyed occupants. Dozens of people watched her go, a disoriented woman who had obviously just suffered a grievous assault. No one intervened. Meanwhile, Tiffany Alexander and her three friends came by a police squad car about half a mile after the bridge. They pulled over to see if someone had reported the incident. The cop told them a report had just come in and that police would respond. The friends decided to turn around and see for themselves. Bridge traffic on the way back was clogged. Tiffany's car inched along. Then, up ahead and on the right, beyond a concrete barrier that separated traffic from the sidewalk, Tiffany saw a lone figure walking along the edge of the bridge. Some estimates suggest that from the time the assault began, nearly half an hour had elapsed. Tiffany was close enough to see that Deletha Word was a brown-skinned woman and that her hair was askew. Tiffany and her friends did not get out of their car. The woman stumbled along. Investigators later concluded, from the trail of blood Deletha left behind, that she walked one hundred seventy feet from the scene of the fender bender. When Deletha drew level with Tiffany's SUV, she looked over her shoulder. It was like a scene from a horror movie: Martell was coming after her again. He was now carrying the tire iron. Deprived of escape and surrounded by dozens of gawking witnesses who seemed frozen in their cars, Deletha did the only thing possible. She climbed the outer rail of the bridge. Between forty and a hundred people saw what was happening: a lone woman, helpless and terrified, clinging to a rail, perilously hanging thirty feet above the surging currents of the Detroit River. Tiffany's heart was in her mouth. But none of the bystanders lifted a finger.

'You can't go out that way,' Martell taunted. He took another step toward Deletha. He raised the tire iron. He was only six feet away. Deletha looked at Martell and the gaping crowd. The dark water beneath her was terrifying; she did not know how to swim. But between the swirling river and the indifferent strangers on the bridge, she preferred her chances with drowning. She let go of the railing and plummeted from sight. The crowd gasped. It would have taken less than one and a half seconds for her to hit the water. Within a moment, the current had her in its grip. How long did she thrash in terror? It could have been minutes, or much longer. When her drowned body was finally recovered the following day, it had been in the water for nine hours. The corpse was missing a leg. Somewhere along a ten-mile journey downriver, a boat propeller had severed Deletha's right leg at the hip.

In the days that followed, outrage grew over the incident. It turned out that Tiffany Alexander was not alone in failing to use her cellphone to immediately call for help. For an incident that lasted as long as thirty minutes and had dozens of eyewitnesses, hardly anyone alerted police. Officers were nowhere close to the scene when Deletha jumped off the bridge. Martell even made it home safely that night. He was arrested only the next day after detectives spotted a Chevy Monte Carlo on his street with a hockey mask hanging from the rearview mirror—a description that matched eyewitness reports. Prosecutors matched bloodstains on the hood of the Monte Carlo to Deletha Word. Because people were unable to comprehend how so many bystanders could have idly stood by as a fellow human was killed, the story line quickly became exaggerated. The crowd supposedly egged Martell on. Bystanders allegedly laughed at Deletha's plight. Detroiters such as Tiffany Alexander and Harvey Mayberry came to be seen as heartless. In The Des Moines Register, columnist Donald Kaul damned the whole city: 'Detroit makes people crazy.' Criticism flooded in from as far away as Europe and Asia. Police had a difficult time finding people to testify in court against Martell, because anyone who came forward was immediately asked the most obvious question: Why didn't you do anything to help?

For years after the incident, Tiffany Alexander asked herself the same question. And she wasn't alone. Why did Harvey Mayberry, Lehjuan Jones, Raymont McGore, and Michael Sandford not stand up to Martell Welch, when each believed in his heart that it was the right thing to do? Is it possible that everyone on the bridge that night was a callous coward? When asked, each person came up with a reason they had not acted. 'There was nothing I could do, being a woman and him being a big man,' Alexander said, but she knew it wasn't true. Even if people had been afraid to physically intervene, what would it have taken to call the police right away? And even if people had been afraid to intervene on their own, surely they could have confronted Martell as a group? Did Deletha Word have the misfortune of spending her final moments surrounded by a uniquely callous selection of humanity? One piece of evidence suggested otherwise: The bystanders were stricken with guilt afterward. On learning that Deletha was the mother of a thirteen-year-old girl, Tiffany's anguish caused her to burst into action. She decided to step forward, identify Martell from a police lineup, and testify against him in court. Yes, she told police, she had seen the assault begin and had seen it end. After Deletha had plunged to her death, the four friends in Tiffany's car had driven a little farther on the bridge, pulled a U-turn, and passed Martell's car again. Deletha's assailant was on his way home. He was so close that Tiffany could see him mopping perspiration from his brow with a towel. No one else in Tiffany's car wanted to have anything to do with the trial and the adverse publicity. But Tiffany stuck to her decision, even though it meant harassment whenever she left her house. She started wearing a wig to keep people from recognizing her as one of the coldhearted bystanders on the Belle Isle bridge.

What do you think happened on the bridge that night? From the outrage that followed, you would think Deletha had been surrounded by the only people in the world who would not help a victim in distress. Everyone else swore they would have come to her aid. Children in schools told reporters they would not have sat idly by. The right course of action was obvious: Step forward, do something, think for yourself. If Tiffany Alexander, Harvey Mayberry, Lehjuan Jones, Raymont McGore, and Michael Sandford had not been eyewitnesses to a horror but victims themselves, surely they would have expected others to use their heads a little better.

This was my own view of the tragedy when I first heard about it as a reporter. It was not until I started learning about the hidden brain that I realized there was an entirely different way to think about what had happened. The more I learned, the more I came to see that Mayberry, Sandford, McGore, Jones, and Alexander did not really have insight into their own behavior. My research into the tragedy of the Belle Isle bridge led me—unexpectedly—to a beautiful September morning in New York in 2001.

Excerpted from The Hidden Brain by Shankar Vedantam Copyright © 2010 by Shankar Vedantam. Excerpted by permission of Random House Group, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.

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