The Undoing Project

by Michael Lewis

  For Redelmeier, medical analogies popped quickly to mind. “Whatever the general example was, I knew a bunch of instantaneous medical examples. It was just astonishing that he would shut up and listen to me.” A medical analogy of Samuelson’s bet, Redelmeier decided, could be found in the duality in the role of the physician. “The physician is meant to be the perfect agent for the patient as well as the protector of society,” he said. “Physicians deal with patients one at a time, whereas health policy makers deal with aggregates.”

  But there was a conflict between the two roles. The safest treatment for any one patient, for instance, might be a course of antibiotics; but the larger society suffers when antibiotics are overprescribed and the bacteria they were meant to treat evolved into versions of themselves that were more dangerous and difficult to treat. A doctor who did his job properly really could not just consider the interests of the individual patient; he needed to consider the aggregate of patients with that illness. The issue was even bigger than one of public health policy. Doctors saw the same illness over and again. Treating patients, they weren’t merely making a single bet; they were being asked to make that same bet over and over again. Did doctors behave differently when they were offered a single gamble and when they were offered the same gamble repeatedly?

  The paper subsequently written by Amos with Redelmeier* showed that, in treating individual patients, the doctors behaved differently than they did when they designed ideal treatments for groups of patients with the same symptoms. They were likely to order additional tests to avoid raising troubling issues, and less likely to ask if patients wished to donate their organs if they died. In treating individual patients, doctors often did things they would disapprove of if they were creating a public policy to treat groups of patients with the exact same illness. Doctors all agreed that, if required by law, they should report the names of patients diagnosed with a seizure disorder, diabetes, or some other condition that might lead to loss of consciousness while driving a car. In practice, they didn’t do this—which could hardly be in the interest even of the individual patient in question. “This result is not just another manifestation of the conflict between the interests of the patient and the general interests of society,” Tversky and Redelmeier wrote, in a letter to the editor of the New England Journal of Medicine. “The discrepancy between the aggregate and the individual perspectives also exists in the mind of the physician. The discrepancy seems to call for a resolution; it is odd to endorse a treatment in every case and reject it in general, or vice versa.”

  The point was not that the doctor was incorrectly or inadequately treating individual patients. The point was that he could not treat his patient one way, and groups of patients suffering from precisely the same problem in another way, and be doing his best in both cases. Both could not be right. And the point was obviously troubling—at least to the doctors who flooded the New England Journal of Medicine with letters written in response to the article. “Most physicians try to maintain this facade of being rational and scientific and logical and it’s a great lie,” said Redelmeier. “A partial lie. What leads us is hopes and dreams and emotion.”

  Redelmeier’s first article with Amos led to other ideas. Soon they were meeting not in Amos’s office in the afternoon but at Amos’s home late at night. Working with Amos wasn’t work. “It was pure joy,” said Redelmeier. “Pure fun.” Redelmeier knew at some deep level that he was in the presence of a person who would change his life. Many sentences popped out of Amos’s mouth that Redelmeier knew he would forever remember:

  A part of good science is to see what everyone else can see but think what no one else has ever said.

  The difference between being very smart and very foolish is often very small.

  So many problems occur when people fail to be obedient when they are supposed to be obedient, and fail to be creative when they are supposed to be creative.

  The secret to doing good research is always to be a little underemployed. You waste years by not being able to waste hours.

  It is sometimes easier to make the world a better place than to prove you have made the world a better place.

  Redelmeier half suspected that the reason Amos had so much time for him was that Redelmeier was not married, and was willing to treat the hours between midnight and four in the morning as part of a workday. The hours Amos kept were strange, but the discipline he imposed became familiar. “He needs the concrete examples to test his general theories,” said Redelmeier. “Some of the principles were just extremely robust, and I was supposed to find examples and give voice to them in a particular domain, medicine.” Amos had a clear idea of how people misperceived randomness, for instance. They didn’t understand that random sequences seemed to have patterns in them: People had incredible ability to see meaning in these patterns where none existed. Watch any NBA game, Amos explained to Redelmeier, and you saw that the announcers, the fans, and maybe even the coaches seemed to believe that basketball shooters had the “hot hand.” Simply because some player had made his last few shots, he was thought to be more likely to make his next shot. Amos had collected data on NBA shooting streaks to see if the so-called hot hand was statistically significant—he already could persuade you that it was not. A better shooter was of course more likely to make his next shot than a less able shooter, but the streaks observed by fans and announcers and the players themselves were illusions. He asked Redelmeier to find in medicine the same sort of false pattern–seeking behavior exhibited by basketball announcers.

  Redelmeier soon returned with the widely held belief that arthritis pain was related to the weather. For thousands of years, people had imagined this connection; it could be traced back to Hippocrates, who wrote, in 400 BC, about the effect of wind and rain on disease. In the late 1980s, doctors were still suggesting to arthritis patients that they move to warmer climates. Working with Amos, Redelmeier found a large group of arthritis patients and asked them to report their pain levels. He then matched these to weather reports. Pretty quickly, he and Amos established that, despite the patients’ claims that their pain changed with the weather, there was no meaningful correlation between the two. They didn’t stop there, however. Amos wanted to explain why people saw this connection between their pain and the weather. Redelmeier interviewed the patients whose pain he had proven to be unrelated to the weather: All but one of them still insisted that their pain was related to the weather and cited, as evidence, the few random moments that justified their belief. Basketball experts seized on random streaks as patterns in players’ shooting that didn’t exist. Arthritis sufferers found patterns in suffering that didn’t exist. “We attribute this phenomenon to selective matching,” Tversky and Redelmeier wrote.† “. . . For arthritis, selective matching leads people to look for changes in the weather when they experience increased pain, and pay little attention to the weather when their pain is stable. . . . [A] single day of severe pain and extreme weather might sustain a lifetime of belief in a relation between them.”

  There might not be a pattern in arthritis pain, but, to Redelmeier’s eye, there appeared to be a very clear pattern in his collaboration with Amos. Amos had all these general ideas about the pitfalls in the human mind when it was required to render judgments in conditions of uncertainty. Their implications for medicine had gone pretty much entirely unexplored. “Sometimes I felt Amos was pilot-testing ideas in front of me,” said Redelmeier. “To see if they were germane to the real world.” Redelmeier could not help but sense that medicine, for Amos, was “just the tiniest little sliver of his interests.” Another human activity in which to explore the specific consequences of the general ideas he had hatched with Danny Kahneman.

  Then Danny himself appeared. In late 1988 or maybe early 1989, Amos introduced them in his office. Danny followed up with a phone call to Redelmeier, in which he said how he, too, might like to explore how doctors and patients made decisions. It turned out that Danny had his own
ideas, with their own implications. “When he calls me, Danny is working alone,” said Redelmeier. “He wants to introduce another heuristic. One that is all his own, separate from Amos. The introduction of a fourth heuristic. Because there can’t be just three.”

  One day in the summer of 1982 Danny, in his third year as a professor at the University of British Columbia, had walked into his lab and surprised his graduate students with an announcement: They’d now study happiness. Danny had always been curious about people’s ability, or inability, to predict their feelings about their own experiences. Now he wanted to study it. Specifically, he wanted to explore the gap—he had sensed it in himself—between a person’s intuitions about what made him happy and what actually made him happy. He thought he might start by having people guess how happy it would make them to come into the lab every day for a week and do something that they said they enjoyed—eat a bowl of ice cream, say, or listen to their favorite song. He might then compare the pleasure they anticipated to the pleasure they experienced, and further compare the pleasure they experienced to the pleasure they remembered. There was clearly a difference to be explored, he argued. At the moment your favorite soccer team wins the World Cup, you are beyond elated; six months later, it means next to nothing to you, really. “For a long time there were no subjects involved,” recalled Dale Miller, a graduate student of Danny’s. “He was just designing these experiments.” What Danny imagined is that people wouldn’t be especially good at predicting their own happiness—and his first experiments, on a handful of subjects, suggested he was onto something. A man whom no one would ever have described as happy was setting out, to the wonder of those who knew him, to discover the rules of happiness.

  Or maybe he was merely sowing doubt in the minds of people who thought they knew what it meant to be happy. At any rate, by the time Amos introduced him to Redelmeier, Danny had moved from the University of British Columbia to the University of California, Berkeley, and from happiness to unhappiness. He was now investigating not only the gap between people’s anticipation of pleasure and their experience of pleasure but also the gap between people’s experience of pain and their memory of it. What did it mean if people’s prediction of the misery that might be caused by some event was different from the misery they actually experienced when the event occurred, or if people’s memory of an experience turned out to be meaningfully different from the experience as it had actually played out? A lot, thought Danny. People had a miserable time for most of their vacation and then returned home and remembered it fondly; people enjoyed a wonderful romance but, because it ended badly, looked back on it mainly with bitterness. They didn’t simply experience fixed levels of happiness or unhappiness. They experienced one thing and remembered something else.

  When he met Redelmeier, Danny was already running experiments on unhappiness in his Berkeley lab. He’d stick the bare arms of his subjects into buckets of ice water. Each subject was given two painful experiences. He’d then be asked which of the two experiences he’d most like to repeat. Funny things happened when you did this with people. Their memory of pain was different from their experience of it. They remembered moments of maximum pain, and they remembered, especially, how they felt the moment the pain ended. But they didn’t particularly remember the length of the painful experience. If you stuck people’s arms in ice buckets for three minutes but warmed the water just a bit for another minute or so before allowing them to flee the lab, they remembered the experience more fondly than if you stuck their arms in the bucket for three minutes and removed them at a moment of maximum misery. If you asked them to choose one experiment to repeat, they’d take the first session. That is, people preferred to endure more total pain so long as the experience ended on a more pleasant note.

  Danny wanted Redelmeier to find him a real-world medical example of what he was calling the “peak-end rule.” It didn’t take long for Redelmeier to come up with a bunch, but they settled on colonoscopies. In the late 1980s, colonoscopies were painful, and not merely dreaded. The discomfort of the procedure dissuaded people from returning for another one. By 1990, colon cancer was killing sixty thousand people every year in the United States alone. Many of its victims would have survived had their cancer been detected at an early stage. One of the big reasons colon cancer went undetected was that people found their first colonoscopy so unpleasant that they elected not to return for a second one. Was it possible to alter their memory of the experience so that they might forget how unpleasant it was?

  To answer the question, Redelmeier ran an experiment on roughly seven hundred people over a period of a year. One group of patients had the colonoscope yanked out of their rear ends at the end of their colonoscopy without ceremony; the other group felt the tip of the scope lingering in their rectums for an extra three minutes. Those extra three minutes were not pleasant. They were merely less unpleasant than the other procedure. The patients in the first group were on the receiving end of an old-fashioned wham-bam-thank-you-ma’am colonoscopy; those in the second group enjoyed a sweeter, or less painful, ending. The sum total of pain experienced by the second group was, however, greater. The patients in the second group experienced all the pain that those in the first group experienced, plus the extra three minutes’ worth.

  An hour after the procedure, the researchers entered the recovery room and asked the patients to rate their experience. Those who had been given the less unhappy ending remembered less pain than did the patients who had not. More interestingly, they proved more likely to return for another colonoscopy when the time came. Human beings who had never imagined that they might prefer more pain to less could nearly all be fooled into doing so. As Redelmeier put it, “Last impressions can be lasting impressions.”

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  Working with Danny was different from working with Amos. Redelmeier’s mental picture of Amos was always crystal clear. Danny left behind a more complicated and murkier impression. Danny was not joyful: Danny was maybe even depressed. He suffered for his work, and so those who worked with him inevitably suffered a bit, too. “He was more likely to see what was wrong with the work and less likely to see what was right with it,” said Redelmeier. And yet what came out of his mind was also, obviously, spectacular.

  It was odd, when Redelmeier stopped to think about it, how little he ever learned about Amos’s and Danny’s lives. “Amos told me very, very little about his life,” he said. “He never talked about Israel. He never talked about the wars. He didn’t talk about the past. It’s not that he was deliberately evasive. It’s just that he controlled the agenda.” The agenda, when they were together, was to analyze human behavior in the delivery of health care. He didn’t presume to ask Danny or Amos about their past or their relationship to each other. And so he never found out how or why they had left Hebrew University and Israel for North America. Or why Amos had spent the 1980s as an exalted chaired professor of behavioral science at Stanford, while Danny passed most of that time in relative obscurity at the University of British Columbia. The two men seemed friendly enough, but they weren’t obviously working together: Why was that? Redelmeier didn’t know. “And they wouldn’t talk about each other,” he said.

  Instead they seemed to have decided they’d bag more game if they hunted separately rather than together. Both were engaged, in different ways, in extending the ideas that they had given birth to jointly in the real world. “I was thinking they were just buddies and I was their pet schnauzer,” said Redelmeier.

  Redelmeier returned to Toronto in 1992. The experience working with Amos had been life-altering. The man was so vivid that you could not confront any question without wondering how he would approach it. And yet, as Amos always seemed to have all the big ideas, and simply needed medical examples to illustrate them, Redelmeier was left with the feeling that maybe he hadn’t done very much. “In many ways I was a glorified secretary, and that troubled me for many years,” he said. “Deep down, I thought I was extremely replaceable. W
hen I came back to Toronto, I wondered: Was it just Amos? Or was there something Redelmeier?”

  Still, only a few years earlier, he’d imagined that he might wind up a general practitioner in a small village in northern Labrador. Now he had a particular ambition: to explore, as both researcher and doctor, the mental mistakes that doctors and their patients made. He wanted to combine cognitive psychology, as practiced by Danny and Amos, with medical decision making. How exactly he would do this he could not immediately say. He was still too unsure of himself. All he knew for sure was that by working with Amos Tversky, he had discovered this other side to himself: a seeker of truth. He wanted to use data to find true patterns in human behavior, to replace the false ones that governed people’s lives and, often, their deaths. “I didn’t really know it was in there,” Redelmeier said of this side of himself. “Amos doesn’t uncover it. He implants it. He sends me as a messenger to a land in the future that he will never see.”

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