Michael Lewis is one of the highest paid writers in the world, and virtually every piece of writing I read of his is a reminder as to why. His latest book, The Undoing Project: A Friendship That Changed Our Minds, is a stellar story about Daniel Kahneman and Amos Tversky’s pathbreaking research in psychology.
So many popular modern ideas about psychology and cognitive bias and happiness came from Kahneman and Tversky. So many phrases and heuristics and frameworks I have cited without knowing the researchers who first discovered them, who coined them, who explained them: these two!
The book is also a fascinating psychological profile of a partnership between two brilliant men. Lewis refers to it as a non-sexual love story, with all the corresponding ups and downs.
My highlights below — bold font is my own.
Later, when basketball scouts came to him looking for jobs, the trait he looked for was some awareness that they were seeking answers to questions with no certain answers—that they were inherently fallible. “I always ask them, ‘Who did you miss?’” he said. Which future superstar had they written off, or which future bust had they…
He had a diffidence about him—an understanding of how hard it is to know anything for sure. The closest he came to certainty was in his approach to making decisions. He never simply went with his first thought. He suggested a new definition of the nerd: a person who knows his own mind well enough to mistrust it.
“Knowledge is literally prediction,” said Morey. “Knowledge is anything that increases your ability to predict the outcome. Literally everything you do you’re trying to predict the right thing. Most people just do it subconsciously.”
Soon Morey noticed something else: A scout watching a player tended to form a near-instant impression, around which all other data tended to organize itself. “Confirmation bias,” he’d heard this called. The human mind was just bad at seeing things it did not expect to see, and a bit too eager to see what it expected to see.
In some strange way people, at least when they were judging other people, saw what they expected to see and were slow to see what they hadn’t seen before. How bad was the problem? When Jeremy Lin’s coach at the New York Knicks finally put him in the game—because everyone else was injured—and allowed him to light up Madison Square Garden, the Knicks were preparing to release Jeremy Lin. Jeremy Lin had already decided that if he was released he’d simply quit basketball altogether. That’s how bad the problem was: that a very good NBA player would never have been given a serious chance to play in the NBA, simply because the minds of experts had concluded he did not belong. How many other Jeremy Lins were out there?
“His defining emotion is doubt,” said one of his former students. “And it’s very useful. Because it makes him go deeper and deeper and deeper.”
And that’s pretty much what Danny Kahneman remembered, or chose to remember, when asked about his childhood. From the age of seven he had been told to trust no one, and he’d obliged.
Presented with two lines of equal length, the eye is tricked into seeing one as being longer than the other. Even after you prove to people, with a ruler, that the lines are identical, the illusion persists: They’ll insist that one line still looks longer than the other. If perception had the power to overwhelm reality in such a simple case, how much power might it have in a more complicated one?
The University of Michigan psychologist Dick Nisbett, after he’d met Amos, designed a one-line intelligence test: The sooner you figure out that Amos is smarter than you are, the smarter you are.
Shore asked him how he had become a psychologist. “It’s hard to know how people select a course in life,” Amos said. “The big choices we make are practically random. The small choices probably tell us more about who we are. Which field we go into may depend on which high school teacher we happen to meet. Who we marry may depend on who happens to be around at the right time of life. On the other hand, the small decisions are very systematic. That I became a psychologist is probably not very revealing. What kind of psychologist I am may reflect deep traits.”
The reigning theories in psychology of how people made judgments about similarity all had one thing in common: They were based on physical distance.
People thought Tel Aviv was like New York but that New York was not like Tel Aviv.
People thought that the number 103 was sort of like the number 100, but that 100 wasn’t like 103. People thought a toy train was a lot like a real train but that a real train was not like a toy train.
“The directionality and asymmetry of similarity relations are particularly noticeable in similes and metaphors,” Amos wrote. “We say ‘Turks fight like tigers’ and not ‘tigers fight like Turks.’
“It is generally assumed that classifications are determined by similarities among the objects,” wrote Amos, before offering up an opposing view: that “the similarity of objects is modified by the manner in which they are classified.
A banana and an apple seem more similar than they otherwise would because we’ve agreed to call them both fruit. Things are grouped together for a reason, but, once they are grouped, their grouping causes them to seem more like each other than they otherwise would. That is, the mere act of classification reinforces stereotypes. If you want to weaken some stereotype, eliminate the classification.
What Europeans often said about Americans—how wildly informal and improvisational they were—was, to her, even more true of Israelis.
Danny was then helping the Israeli Air Force to train fighter pilots. He’d noticed that the instructors believed that, in teaching men to fly jets, criticism was more useful than praise. They’d explained to Danny that he only needed to see what happened after they praised a pilot for having performed especially well, or criticized him for performing especially badly. The pilot who was praised always performed worse the next time out, and the pilot who was criticized always performed better. Danny watched for a bit and then explained to them what was actually going on: The pilot who was praised because he had flown exceptionally well, like the pilot who was chastised after he had flown exceptionally badly, simply were regressing to the mean. They’d have tended to perform better (or worse) even if the teacher had said nothing at all. An illusion of the mind tricked teachers—and probably many others—into thinking that their words were less effective when they gave pleasure than when they gave pain. Statistics wasn’t just boring numbers; it contained ideas that allowed you to glimpse deep truths about human life. “Because we tend to reward others when they do well and punish them when they do badly, and because there is regression to the mean,” Danny later wrote,
The only way to understand a mechanism such as the eye, he thought, was by studying the mistakes that it made. Error wasn’t merely instructive; it was the key that might unlock the deep nature of the mechanism. “How do you understand memory?” he asked. “You don’t study memory. You study forgetting.”
Anne Treisman was on a flying visit to Harvard, where the demand to hear what she had to say was so great that her talk had to be moved to a big public lecture hall off campus. Danny left the talk filled with new enthusiasm. He asked to be deputized to look after Treisman and her traveling party—which included her mother, her husband, and their two small children. He gave them a tour of Harvard. “He was very eager to impress,” said Treisman, “and so I let myself be impressed.” It would be years before Danny and Anne left their marriages and married each other, but it took no time at all for Danny to engage Treisman’s ideas.
In very large populations, the law of large numbers did indeed guarantee this result. If you flipped a coin a thousand times, you were more likely to end up with heads or tails roughly half the time than if you flipped it ten times. For some reason human beings did not see it that way. “People’s intuitions about random sampling appear to satisfy the law of small numbers, which asserts that the law of large numbers applies to small numbers as well,” Danny and Amos wrote.
An old friend of Amos’s would later recall, “Amos would say, ‘People are not so complicated. Relationships between people are complicated.’ And then he would pause, and say: ‘Except for Danny.’”
For instance, in families with six children, the birth order B G B B B B was about as likely as G B G B B G. But Israeli kids—like pretty much everyone else on the planet, it would emerge—naturally seemed to believe that G B G B B G was a more likely birth sequence. Why? “The sequence with five boys and one girl fails to reflect the proportion of boys and girls in the population,” they explained. It was less representative. What is more, if you asked the same Israeli kids to choose the more likely birth order in families with six children—B B B G G G or G B B G B G—they overwhelmingly opted for the latter. But the two birth orders are equally likely.
Amos liked to say that if you are asked to do anything—go to a party, give a speech, lift a finger—you should never answer right away, even if you are sure that you want to do it. Wait a day, Amos said, and you’ll be amazed how many of those invitations you would have accepted yesterday you’ll refuse after you have had a day to think it over. A corollary to his rule for dealing with demands upon his time was his approach to situations from which he wished to extract himself…who finds himself stuck at some boring meeting or cocktail party often finds it difficult to invent an excuse to flee. Amos’s rule, whenever he wanted to leave any gathering, was to just get up and leave. Just start walking and you’ll be surprised how creative you will become and how fast you’ll find the words for your excuse, he said.
It confirmed Biederman’s sense that “most advances in science come not from eureka moments but from ‘hmmm, that’s funny.’”
Across North America, more people died every year as a result of preventable accidents in hospitals than died in car crashes—which was saying something.
Bad things even happened to people when they pressed hospital elevator buttons. Redelmeier had actually co-written an article about that: “Elevator Buttons as Unrecognized Sources of Bacterial Colonization in Hospitals.” For one of his studies, he had swabbed 120 elevator buttons and 96 toilet seats at three big Toronto hospitals and produced evidence that the elevator buttons were far more likely to infect you with some disease.
Whenever a patient recovered, for instance, the doctor typically attributed the recovery to the treatment he had prescribed, without any solid evidence that the treatment was responsible. Just because the patient is better after I treated him doesn’t mean he got better because I treated him, Redelmeier thought. “So many diseases are self-limiting,” he said. “They will cure themselves. People who are in distress seek care. When they seek care, physicians feel the need to do something. You put leeches on; the condition improves. And that can propel a lifetime of leeches. A lifetime of overprescribing antibiotics. A lifetime of giving tonsillectomies to people with ear infections. You try it and they get better the next day and it is so compelling. You go to see a psychiatrist and your depression improves—you are convinced of the efficacy of psychiatry.”
By the end of Redelmeier’s medical training, seven years later, researchers had shown that heart attack patients whose arrhythmia was suppressed died more often than the ones whose condition went untreated. No one explained why doctors, for years, had opted for a treatment that systematically killed patients—though proponents of evidence-based medicine were beginning to look to the work of Kahneman and Tversky for possible explanations.
Surgery was more likely to extend your life, but, unlike radiation, it came with the small risk of instant death. When you told people that they had a 90 percent chance of surviving surgery, 82 percent of patients opted for surgery. But when you told them that they had a 10 percent chance of dying from the surgery—which was of course just a different way of putting the same odds—only 54 percent chose the surgery.
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.
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.
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.”
People did not seek to avoid other emotions with the same energy they sought to avoid regret. When they made decisions, people did not seek to maximize utility. They sought to minimize regret.
Why didn’t people regret Israel’s inaction? Amos and Danny had a thought: People regretted what they had done, and what they wished they hadn’t done, far more than what they had not done and perhaps should have.
They spent more than a year working and reworking the same basic idea: In order to explain the paradoxes that expected utility could not explain, and create a better theory to predict behavior, you had to inject psychology into the theory.
“Happy species endowed with infinite appreciation of pleasures and low sensitivity to pain would probably not survive the evolutionary battle,” they wrote.
The two problems were identical, but, in the first case, when the choice was framed as a gain, the subjects elected to save 200 people for sure (which meant that 400 people would die for sure, though the subjects weren’t thinking of it that way). In the second case, with the choice framed as a loss, they did the reverse, and ran the risk that they’d kill everyone. People did not choose between things. They chose between descriptions of things.
By 1976, purely for marketing purposes, they changed their title to “Prospect Theory.” “The idea was to give the theory a completely distinct name that would have no associations whatsoever,” said Danny. “When you say ‘prospect theory,’ no one knows what you’re talking about. We thought: Who knows? It may turn out to be influential. And if it is we don’t want it to be confused with anything else.”
Then he came straight out with his own feelings about Amos getting the lion’s share of the glory for work they had done together. “I am very much in his shadow in a way that is not representative of our interaction,” he said. “It induces a certain strain. There is envy! It’s just disturbing. I hate the feeling of envy. . . . I am maybe saying too much now.”
It was those constraints that Danny set out to investigate. He wanted to understand better what he was now calling “counterfactual emotions,” or the feelings that spurred people’s minds to spin alternative realities in order to avoid the pain of the emotion. Regret was the most obvious counterfactual emotion, but frustration and envy shared regret’s essential trait. “The emotions of unrealized possibility,” Danny called them, in a letter to Amos.
Toward the end of his thinking on the subject, he summed up a lot in a single sentence: “Reality is a cloud of possibility, not a point.”
What Danny needed was for Amos to continue to see him and his ideas uncritically, as he had when they were alone together in a room. If that involved some misperception on Amos’s part—some exaggeration of the earthly status of Danny’s ideas—well, then, Amos should continue to misperceive. After all, what is a marriage if not an agreement to distort one’s perception of another, in relation to everyone else? “I wanted something from him, not from the world,” said Danny.
But because he was Danny, he made a rule about his fantasy life: He never fantasized about something that might happen. He established this private rule for his imagination once he realized that, after he had fantasized about something that might actually happen, he lost his drive to make it happen. His fantasies were so vivid that “it was as if you actually had it,” and if you actually had it, why would you bother to work hard to get…