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

by Shankar Vedantam

  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.

  Six years after Deletha’s death, a young equity trader at a financial services investment bank in New York went to work on a sunny Tuesday morning in September. Bradley Fetchet had been at Keefe, Bruyette & Woods for less than a year, but his talent had already been noticed. There was another Brad at the firm already, so the twenty-five-year-old Bucknell graduate was given the moniker Fetch. Each day, his mother told me, Fetch took special pride as he stepped into work on the eighty-ninth floor of the South Tower of the World Trade Center. It is not surprising that Fetch came to think of the firm as special. The employees of Keefe, Bruyette & Woods prided themselves on their camaraderie. They thought of themselves as more than colleagues—the firm felt like family. New recruits, in fact, were often literally family—many came to the firm by way of recommendations from relatives at the company. Tied together by blood, outlook, and social ties, the employees formed an unusually cohesive group. On September 11, 2001, the seven-thirty morning meeting at the firm was particularly well attended. As the meeting broke up about an hour later, people drifted back to their desks, chatting with one another before the start of trading at nine o’clock. That was when they heard a terrible muffled noise. It was as if an earthquake had struck. It was eight forty-six A.M. According to an account of the event pieced together by the man who would later become the new head of the firm, the muffled explosion brought Joe Berry, the chairman of the company, running out of his office. “Jesus Christ,” he shouted. “What the hell was that?”

  If the architecture of the Belle Isle bridge produced a situation where Deletha Word’s options for physical escape were tragically limited, the muffled explosion that Fetch and the others heard created a similar situation. What mattered in this case, however, was not the physical structure of the tower but the architecture of time. Fetch and his friends did not know this, but their own lives were in deadly danger. They had just one opportunity for escape—a sliver of a window had been opened by an event hundreds of miles away. Earlier that morning, United Airlines Flight 175 from Boston had seen its takeoff delayed by fourteen minutes at Logan airport. That delay created a small opportunity for Fetch and his friends to survive, but of course the employees of Keefe, Bruyette & Woods did not know that. When Fetch and his friends heard the explosion in the North Tower that Tuesday morning, they did not know the United Airlines plane was sixteen minutes away from crashing into their building. The impact of the United plane would tear a diagonal gash in the South Tower that would stretch from the seventy-seventh to the eighty-fifth floor. Virtually every person who was still in the building above the zone of impact would die.

  In the overwhelming tragedy that was enveloping the United States, hardly anyone noticed that something strange happened at Keefe, Bruyette & Woods that morning—a puzzle. The investment banking firm was actually spread over two floors in the South Tower, the eighty-eighth floor and the eighty-ninth floor. Escape routes from both floors would be severed by the impact of the United Airlines plane. But when the survivors were accounted for, it turned out that nearly every employee on the eighty-eighth floor escaped and survived. Fetch and nearly everyone else who worked for the same company on the eighty-ninth floor stayed at their desks and died. John Duffy, who became CEO of the firm after the tragedy—and whose son was among the employees who died—told me that 120 employees were spread over the eighty-eighth and eighty-ninth floors that morning. Of the sixty-seven people at the firm who died, sixty-six worked on the eighty-ninth floor. Only one person who died worked on the eighty-eighth floor, and, as we will see, that death was the result of a conscious act of courage.

  Accounts pieced together from telephone calls made from the eighty-ninth floor and accounts from a few survivors show that Fetch and the others did not know that the explosion they heard was caused by a plane crash—the North Tower was not directly visible from the firm’s trading area in the South Tower. But from their perch in the sky, they saw smoke and thousands of pieces of paper drifting across the sky. One employee would later say it looked like a ticker tape parade. Confusion broke out. People raced to windows for a better look. Senior staff recalled what happened during the terrorist attack on the World Trade Center in 1993. Those who tried to leave got stuck for hours in elevators. The emerging school of thought in disaster management was that rather than trying to get everyone out of a big building like the World Trade Center, it made sense for people who were not affected by a problem to stay inside their workplaces, rather than wander out into danger. This wisdom had filtered down to every old-timer in the building.

  Put yourself in the shoes of the people on the eighty-ninth floor. You have no idea what is happening. A muffled explosion from an adjoining tower, smoke, and drifting pieces of paper is all the information you have. The idea that nineteen hijackers have taken control of four airplanes and aimed them at the nation’s most prominent landmarks, including the building where you work, is not just beyond the realm of comprehension. It is beyond the realm of imagination. Fetch and his friends also had one nervous eye on the clock—trading on the stock market was to open in a few minutes at nine o’clock.

  Chairman Joe Berry dispatched someone to check with building officials about what to do. Meanwhile, families, friends, and colleagues who heard about the explosion on television started calling to make sure their loved ones were okay. The calls had the unintended effect of keeping employees at their workstations.

  Meanwhile, the United Airlines plane, after initially going southwest through Massachusetts, Connecticut, and New Jersey, pulled a lazy U-turn over Pennsylvania. A subsequent re-creation of its flight path showed that the plane drifted southeast at first, then made a ninety degree left turn at the New Jersey border and headed northeast toward Manhattan.

  Some of Fetch’s colleagues wandered over to windows that offered a good view of the North Tower. Others determinedly settled into their desks to get ready for the start of trading—and advised their slacker friends to do the same. Officials in the building finally announced over the public address system that people in the South Tower could stay where they were rather than risk exiting the building, where they could get hit by falling debris from the North Tower.

  Fetch saw the burning North Tower from a window with a good view. The sight shook him up. He saw someone leaping from an upper floor and falling hundreds of feet. It was horrible. He didn’t realize that something even worse was about to happen. United Flight 175 was plunging ten thousand feet a minute, aimed at the southern tip of Manhattan. Fetch did what anyone else might do in his situation, what most of the people around him were doing. He picked up the phone. He called his father at work. After a brief conversation, he hung up. The United plane was only moments away. Fetch dialed another number. He wanted to reassure his mother that he was all right. Mary Fetchet was not in, so Fetch left her a message.

  “He said, ‘I want to tell you the plane hit tower two and I am in tower one and I am alive and well,’” Mary
Fetchet recalled in an interview. “He said, ‘It was pretty frightening because I saw someone fall from the ninetieth floor all the way down.’ There was a long pause. He cleared his voice and said, ‘Give me a call. I think I will be here the rest of the day. I love you.’”

  Seconds later, Fetch’s building shuddered violently with the impact of United Flight 175. Virtually no one on the upper floors knew that one stairwell in the building survived the crash. Nearly everyone above the zone of impact who did not escape within the sixteen-minute window perished.

  What happened on the eighty-eighth floor of Keefe, Bruyette & Woods? The employees there had the same culture and camaraderie as their colleagues on the eighty-ninth floor. They knew the same things about the building. They experienced the same confusion when they heard the explosion in the North Tower. They had the same doubts about what to do. Friends and family were calling people on this floor, too. People here had heard the frustrated accounts of those who’d tried to get out of the building after the 1993 attack. The announcement telling people to stay put reached the eighty-eighth floor as clearly as it did the eighty-ninth floor. Some people on the eighty-eighth floor jumped up when they heard the explosion from the North Tower. They looked at one another in horror. One man, J. J. Aguiar, ran through the floor screaming at people to leave. But as we have seen, there were plenty of other forces prompting people to stay. Given all the evidence, why did the people on this floor evacuate en masse?

  It is important to emphasize that it is only in hindsight that we know that the people on the eighty-eighth floor who ran down the stairs after hearing the first explosion did the right thing. Toward the end of his suicidal descent, Marwan al-Shehhi, the terrorist at the controls of the United Airlines plane, dropped more than twenty-five thousand feet in a few minutes. The plane was traveling at nearly six hundred miles per hour at the moment of impact. If the nose of the plane had been tilted just a fraction of a degree in one direction, everyone on the eighty-ninth floor might have survived, too. If the plane had struck one of the lower floors, some of those who fled the eighty-eighth floor might have been just as unlucky as the people who stayed at their desks on the eighty-ninth floor.

  If the explosion in the North Tower had been the result of an accident rather than terrorism, a scenario that seemed far more plausible during those first sixteen minutes, then the people who stayed in their offices on the eighty-ninth floor might have ended up looking like the wise ones, while the people who ran outside might have been hit by falling debris. The point is not that employees on one floor made the “right” decision while the employees on the other floor made the “wrong” decision.

  The point is that on each floor virtually everyone reached the same decision.

  But wasn’t every employee at Keefe, Bruyette & Woods that morning making decisions on his or her own? Wasn’t every employee exercising judgment? If all the people were making deliberate and individual decisions to evacuate or stay, shouldn’t we expect to see a similar balance of decisions on both floors? Many people on the eighty-ninth floor should have decided to leave, while many people on the eighty-eighth floor should have stayed. That, emphatically, is not what happened. Nearly everyone on one floor left. Nearly everyone on the other stayed. Could every employee on the eighty-eighth floor have independently reached one conclusion, while nearly every employee on the eighty-ninth floor independently reached the opposite conclusion? The odds of this happening purely by chance are similar to the odds that you’d find one particular grain of sand among all the beaches in the world.

  Studying the decisions of individuals has not told us why people on one floor escaped while people on the other floor stayed. Could our approach to the puzzle have been wrong? Rather than focus on the details of why people stayed or left, perhaps we ought to step back—the evidence, after all, shows a mass decision to leave one floor, and a mass decision to stay behind on the other. Trying to understand mass decisions by studying individuals is like photographing a panoramic scene with a zoom lens rather than a panoramic lens. The details keep us from seeing the larger picture. All we see is chaos and caprice—or what a scientist would call noise.

  What happens if we step back? We see something quite different. If you happened to be part of the group on the eighty-eighth floor, you ran for the stairs because everyone else was running for the stairs. If you happened to be part of the group on the eighty-ninth floor, you stayed because nearly everyone else was staying, too. It is crucial to note that the people on the two floors, just like the bystanders on the Belle Isle bridge, did not explicitly think about their actions this way. No, every person felt they were making autonomous decisions. But the evidence shows that the decision that made the difference between life and death that morning was not made by individuals. That decision was made, for lack of a better term, by groups. Group decisions provide us with a signal. The details about individuals—who did what, who felt what, who thought what—is noise.

  Three years before the 2001 attacks, a sociologist named Beningo Aguirre published an extraordinary paper in an obscure journal called Sociological Forum. Although the paper spoke directly to their situation, the information in it was nothing that the employees of Keefe, Bruyette & Woods could have been expected to know. Aguirre sent out questionnaires to people who were in the World Trade Center during the 1993 attack, when terrorists detonated a car bomb in the B-2 level of the parking garage. The explosion created a crater that was three-quarters of an acre in size, and seven stories in depth. It disabled the public address system and sent smoke pouring through air vents. Within minutes, the smoke traveled dozens of floors above the underground explosion. Aguirre wanted to find out how quickly people exited the buildings and what factors influenced their escapes. Remarkably, he found that it mattered little whether people were on an upper floor or a lower floor. In other words, being on the fortieth floor didn’t mean that you necessarily took longer to get out of the building than if you were on the thirtieth floor. What really mattered was the size of the groups that people belonged to. The larger the group, the longer it took to escape. It took time for Aguirre to figure out why the size of groups made such a big difference. The sociologist eventually realized that during disasters, people unconsciously seek consensus with those around them. Groups seek to develop a shared narrative—an explanation for what is happening that is shared by everyone. The larger the group, the longer it took to arrive at a consensus.

  People regularly make decisions that do indeed reflect their individual personalities and motivations. But when a disaster befalls a group, the behavior of the group itself, rather than individual decisions, is often decisive. Much of this happens at a subtle level, far below the level of conscious awareness, in the recesses of the hidden brain. In crises, we are hardwired to turn to groups for help and guidance. The ties that bind people together during crises explain why, when fires break out in big buildings, people perish or survive in groups. Fate comes in clusters. Entire families and floors survive, while other families and groups die together. When we try to understand such outcomes, we invariably focus on the thought processes of individuals—people such as Brad Fetchet or Tiffany Alexander—because our starting assumption is that human behavior is always the product of conscious thought and individual decision-making. But we thereby miss what is actually happening—the signal—in all the noise.

  Observe for yourself what happens the next time a fire alarm goes off at your workplace or in any large public space—a subway car or department store. People will look at one another. They may ask one another, “What do you think is going on? Has this happened before? Is it a drill, a false alarm? Do I really need to shut down my computer and leave?”

  Two years after the September 11 attacks, a fire broke out in a Rhode Island nightclub. A pyrotechnic display onstage went awry. A television camera in the back of the room was rolling, and the tape showed that as real fire erupted on the stage, people in the audience turned to one another. The fire set off a conflagrat
ion that killed ninety-six people within minutes. Nearly two hundred people were injured. The window of escape at the nightclub was even smaller than the window of escape at Keefe, Bruyette & Woods. People in the middle of the nightclub needed to act within seconds to have any chance of survival.

  We assume that people inside a confined space will flow out evenly through all available exits during an emergency—because that is what conscious, rational, and autonomous creatures do. When a disaster claims many lives, we immediately ask about the number of exits that were available, about whether signs were clearly posted, and about whether precautions were taken to inform people about escape routes. Journalists write articles about building code violations, lawyers file lawsuits about shoddy construction materials, and policymakers review evacuation procedures. The Rhode Island nightclub fire demonstrated why these responses often miss the mark. Clear exits and evacuation drills are valuable, but they do not begin to address the role of the hidden brain during disasters: The first response of people who are trapped is not to review what they have been taught and make reasoned decisions, but to turn decision-making over to the group.