The Undoing Project: A Friendship That Changed Our Minds
By Michael Lewis
W. W. Norton & Company (2016)

A promised on its cover, The Undoing Project is the story of an important friendship: that between psychologists Amos Tversky and Daniel Kahneman. Tversky and Kahneman are key figures in the study of cognitive biases — e.g., risk aversion, representativeness, anchoring, etc. The upshot: humans are bad at calculating probabilities in our guts. As such, we’re not rational actors.

The book tells the story of Kahneman and Tversky’s collaboration as a straightforward linear narrative. Their biographies track the creation of the state of Israel: Tversky was born there, while Kahneman’s family immigrated after the Holocaust. Both became formative figures in Israel’s armed forces.

Much of The Understanding Project’s appeal lies in the differences between its main actors. Kahneman comes across as conciliatory and filled with self-doubt. (As a colleague puts it, “He was like Woody Allen, without the humor.”) Tversky, on the other hand, was combative and aware of his brilliance. He didn’t care what others thought of him:

… all those who came to know Amos eventually realized was that the man had a preternatural gift for doing only precisely what he wanted to do.

The differences manifested in their (physical) offices: Kahneman’s was a mess, while Tversky’s was sparse and orderly to the extreme. The Odd Couple vibe comes through in other aspects of their personalities:

Danny was a Holocaust kid; Amos was a swaggering Sabra — the slang term for a native Israeli. Danny was always sure he was wrong. Amos was always sure he was right. Amos was the life of every party; Danny didn’t go to the parties. Amos was loose and informal; even when he made a stab at informality, Danny felt as if he had descended from some formal place. With Amos you always just picked up where you left off, no matter how long it had been since you last saw him. With Danny there was always a sense you were starting over, even if you had been with him just yesterday. Amos was tone-deaf but would nevertheless sing Hebrew folk songs with great gusto. Danny was the sort of person who might be in possession of a lovely singing voice that he would never discover. Amos was a one-man wrecking ball for illogical arguments; when Danny heard an illogical argument, he asked, What might that be true of? Danny was a pessimist. Amos was not merely an optimist; Amos willed himself to be optimistic, because he had decided pessimism was stupid.

Still, they had lots in common. Both were extraordinary teachers. They were men of action, rushing back to Israel when their country needed them. Both were blindingly brilliant. (I’m writing in the past tense, but Kahneman is still alive, productive, and brilliant.) Their unlikely friendship blossomed into a deep collaboration that, at times, seemed like a marriage.

“We just found each other more interesting than anyone else,” said Danny. “Even if we had just spent the entire day working together.” They’d become a single mind, creating ideas about why people did what they did, and cooking up odd experiments to test them.

Tversky died in 1996. When he was alive, he was the more famous of the two; Kahneman was often in his shadow, perhaps unfairly. Today, Kahneman is better known, having won the 2002 Nobel prize in economics and written the best-selling book Thinking, Fast and Slow. The lopsided recognition, alongside personal evolution, led to the erosion of the relationship.

The Undoing Project is an engaging book. But why read a biography of two psychologists at all? I find it easier to learn about a subject when I understand the stories behind it. And Tversky and Kahneman’s work matters to designers. We create systems that will be used by people who aren’t rational actors. It behooves us to understand how so.

Kahneman and Tversky’s work isn’t just relevant to understanding how humans make decisions, but more broadly, how we grok reality.

“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. Thus, similarity has two faces: causal and derivative. It serves as a basis for the classification of objects, but is also influenced by the adopted classification.”

As Wurman said, the organization of information creates new information — i.e., putting things together leads us to understand them differently. Knowing how we know the world — and therefore, how we act in the world — can help us better design for human use. Understanding Tversky and Kahneman helps, and The Undoing Project is a good way into their work.

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