The Undoing Project: A Friendship that Changed the World(63)

The article was called “Judgment Under Uncertainty: Heuristics and Biases.” It was in equal parts familiar and strange—what the hell was a “heuristic”? Redelmeier was seventeen years old, and some of the jargon was beyond him. But the article described three ways in which people made judgments when they didn’t know the answer for sure. The names the authors had given these—representativeness, availability, anchoring—were at once weird and seductive. They made the phenomenon they described feel like secret knowledge. And yet what they were saying struck Redelmeier as the simple truth—mainly because he was fooled by the questions they put to the reader. He, too, guessed that the guy they named “Dick” and described so blandly was equally likely to be a lawyer or an engineer, even though he came from a pool that was mostly lawyers. He, too, made a different prediction when he was given worthless evidence than when he was given no evidence at all. He, too, thought that there were more words in a typical passage of English prose that started with K than had K in the third position, because the words that began with K were easier to recall. He, too, made predictions about people from mere descriptions of them with a degree of confidence that was totally unjustified—even uncertain Don Redelmeier fell prey to overconfidence! And when asked quickly to guess the product of 1 × 2 × 3 × 4 × 5 × 6 × 7 × 8, he saw how he, too, would think it less than the product of 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1.

What struck Redelmeier wasn’t the idea that people made mistakes. Of course people made mistakes! What was so compelling is that the mistakes were predictable and systematic. They seemed ingrained in human nature. Reading the article in Science reminded Redelmeier of all the times he had made what seemed in retrospect to be an obvious mistake on a math problem—because it was so much like the other mistakes he and others had made. One passage in particular stuck with him—it was in the section on this thing they called “availability.” It talked about the role of the imagination in human error. “The risk involved in an adventurous expedition, for example, is evaluated by imagining contingencies with which the expedition is not equipped to cope,” the authors wrote. “If many such difficulties are vividly portrayed, the expedition can be made to appear exceedingly dangerous, although the ease with which disasters are imagined need not reflect their actual likelihood. Conversely, the risk involved in an undertaking may be grossly underestimated if some possible dangers are either difficult to conceive of, or simply do not come to mind.”

This wasn’t just about how many words in the English language started with the letter K. This was about life and death. “That article was more thrilling than a movie to me,” said Redelmeier. “And I love movies.”

Redelmeier had never heard of the authors—Daniel Kahneman and Amos Tversky—though at the bottom of the page it said that they were members of the Department of Psychology at Hebrew University in Jerusalem. To him it was more important that his older brothers had never heard of them, either. Aha, finally. I know something more than my brothers! he thought. Kahneman and Tversky offered what felt like a private glimpse of the act of thinking. Reading their article was like getting a peek behind the magician’s curtain.

Redelmeier didn’t have much trouble figuring out what he wanted to do with his life. As a kid he’d fallen in love with the doctors on television—Leonard McCoy on Star Trek and, especially, Hawkeye Pierce on M*A*S*H. “I sort of wanted to be heroic,” he said. “I would never cut it in sports. I would never cut it in politics. I would never make it in the movies. Medicine was a path. A way to have a truly heroic life.” He felt the pull so strongly that he applied to medical school at the age of nineteen, during his second year of college. Just after his twentieth birthday he was training, at the University of Toronto, to become a doctor.

And that’s where the problems started: The professors didn’t have much in common with Leonard McCoy or Hawkeye Pierce. A lot of them were self-important and even a bit pompous. Something about them, and what they were saying, led Redelmeier to seditious thoughts. “Early on in medical school there are a whole bunch of professors who are saying things that are wrong,” he recalled. “I don’t dare say anything about it.” They repeated common superstitions as if they were eternal truths. (“Bad things come in threes.”) Specialists from different fields of medicine faced with the same disease offered contradictory diagnoses. His professor of urology told students that blood in the urine suggested a high chance of kidney cancer, while his professor of nephrology said that blood in the urine indicated a high chance of glomerulonephritis—kidney inflammation. “Both had exaggerated confidence based on their expert experience,” said Redelmeier, and both mainly saw only what they had been trained to see.

The problem was not what they knew, or didn’t know. It was their need for certainty or, at least, the appearance of certainty. Standing beside the slide projector, many of them did not so much teach as preach. “There was a generalized mood of arrogance,” said Redelmeier. “ ‘What do you mean you didn’t give steroids!!????’” To Redelmeier the very idea that there was a great deal of uncertainty in medicine went largely unacknowledged by its authorities.

There was a reason for this: To acknowledge uncertainty was to admit the possibility of error. The entire profession had arranged itself as if to confirm the wisdom of its decisions. 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.”