That door was now cracking open. Anne was British. She was also a gentile and the mother of four children, one of whom had Down syndrome. There were about sixteen different reasons she couldn’t, or wouldn’t, move to Israel. And if Anne wasn’t moving to Israel, it followed that Danny would need to leave. Danny and Amos scrambled and found a temporary solution, in 1977, by heading off together from Hebrew University on sabbatical to Stanford University, where Anne might join them. But a few months after their arrival in the United States, Danny announced that he planned to marry Anne and stay. He forced Amos to make a decision about what to do about their relationship.
It was now Amos’s turn to sit down and write an emotional letter. Danny was messy, in a way that Amos could never be messy even if he wanted to be. Amos had wanted to be a poet when he was a boy. He’d wound up a scientist. Danny was a poet, who somehow happened to have become a scientist. Danny felt some obvious desire to be more like Amos; Amos, too, harbored some less obvious desire to be more like Danny. Amos was a genius. But he needed Danny, and he knew it. The letter Amos wrote was to his close friend Gidon Czapski, the rector of Hebrew University. “Dear Gidi,” it began. “The decision to remain here in the United States is the most difficult decision I have ever made. I cannot ignore my desire to bring to a completion, at least partially, the joint work with Danny. I just cannot accept the idea that the joint work of years could come to naught and that we will not be able to complete the ideas we have.” Amos went on to explain that he planned to accept a chaired professorship offered to him by Stanford University. He knew full well that everyone in Israel would be shocked and angry. “If Danny leaves Israel it is a personal tragedy,” a Hebrew University official had said to him not long before. “If you leave it is a national tragedy.”
Until Amos actually left, his friends found it unthinkable that he would live anyplace but Israel. Amos was Israel, and Israel was Amos. Even his American wife was upset. Barbara had fallen in love with Israel—its intensity, its sense of community, its disinterest in small talk. She now thought of herself as more Israeli than American. “I had done so much work to become Israeli,” she said. “I didn’t want to stay in the States. I said to Amos, ‘How can I start over?’ He said, ‘You’ll manage.’”
* * *
* Here is the simpler version of the paradox. Danny and Amos created it to show how the apparent contradiction might be resolved using their findings about people’s attitudes toward probabilities. And so in a funny way they “solved” the Allais paradox twice—once by explaining it with regret, this time by explaining it with their new theory:
You are offered a choice between:
1. $30,000 for sure
2. A gamble that has a 50 percent chance of winning $70,000 and a 50 percent chance of winning nothing
Most people took the $30,000. That was interesting in itself. It showed what was meant by “risk aversion.” People choosing between a bet and a certain amount would accept a certain amount that was less than the expected value of the bet (which here is $35,000). That did not violate utility theory. It just meant that the utility of a chance to win 70 grand is less than the utility of a twice as likely chance to win 30 grand—which in this case makes the 30 grand a certainty. But now consider a second choice between bets:
1. A gamble that gives you a 4 percent chance to win $30,000 and a 96 percent chance to win nothing
2. A gamble that gives you a 2 percent chance to win $70,000 and a 98 percent chance to win nothing
Most people here preferred 2, the lower chance to win more. But that implied that the “utility” of a chance to win $70,000 is greater than the utility of a twice as likely chance to win $30,000—or the opposite of the preferences in the first choice. In Danny and Amos’s working theory, the paradox was now resolved differently. It wasn’t that (or at least not only that) people anticipated regret when making a decision in the first situation that they did not anticipate in making the second. It was that they treated 50 percent as more than 50 percent and saw the difference between 4 percent and 2 percent as far less than it was.
11
THE RULES OF UNDOING
In the late 1970s, not long after he’d become superintendent of the Massachusetts Mental Health Center, Miles Shore realized he had a problem. The center was a teaching hospital for Harvard Medical School, where Shore was Bullard Professor of Psychiatry. Newly installed in administration, he found himself faced with a decision: whether to promote a medical researcher named J. Allan Hobson. It shouldn’t have been that hard. In a series of famous papers, Hobson had landed body blows on the Freudian idea that dreams arose from unconscious desires, by showing that they actually came from a part of the brain that had nothing to do with desire. He’d proven that the timing and the length of dreams were regular and predictable, which suggested that dreams had less to say about a person’s psychological state than about his nervous system. Among other things, Hobson’s research suggested that people who paid psychoanalysts to find meaning in their unconscious states were wasting their money.
Hobson was changing people’s understanding of what happened to the human brain during sleep—but he wasn’t doing it alone. That was Miles Shore’s problem: Hobson hadn’t written his famous papers on dreams by himself, but with a partner named Robert McCarley. “It was very difficult to campaign for promotion for people who did their work collaboratively,” said Shore. “Because the system is based on the individual. It was always: What did this person do to change the field?” Shore wanted to promote Hobson, but he had to argue the case before a skeptical committee. “They basically didn’t want to promote anyone,” said Shore. Resisting the case for Hobson, committee members asked Shore if he could demonstrate exactly how much Hobson had contributed to his partnership with McCarley. “They asked me which one of them did what,” recalled Shore. “And so I went to them [Hobson and McCarley] and asked: ‘Which one of you did what?’ And they said: ‘Which one of us did what? We have no idea. It was a joint product.’” Shore pushed the collaborators a bit until he realized that they really meant it: They had no idea who deserved credit for which idea. “It was really interesting,” said Shore.
So interesting that Shore decided there might be a book in it. He set out to find fertile pairs—people who had been together for at least five years and produced interesting work. By the time he was done he had interviewed a comedy duo; two concert pianists who had started performing together because one of them had stage fright; two women who wrote mysteries under the name “Emma Lathen”; and a famous pair of British nutritionists, McCance and Widdowson, who were so tightly linked that they’d dropped their first names from the jackets of their books. “They were very huffy about the idea that dark bread was more nutritious than white bread,” recalled Shore. “They had produced the research that it wasn’t so in 1934—so why didn’t people stop fooling around with the idea?” Just about every work couple that Shore called were intrigued enough by their own relationships to want to talk about them. The only exceptions were “a mean pair of physicists” and, after flirting with participating, the British ice dancers Torvill and Dean. Among those who agreed to sit down with Miles Shore were Amos Tversky and Daniel Kahneman.