Aptitude tests revealed Danny to be equally suited for the humanities and science, but he only wanted to do science. He also wanted to study people. Beyond that, it soon became clear, he didn’t know what he wanted to do. In his second year at Hebrew University, he listened to a talk by a visiting German neurosurgeon who claimed that damage to the brain caused people to lose the capacity for abstract thought. The claim turned out to be false, but Danny was so taken by it in that moment that he decided to chuck psychology to pursue a medical degree—so that he’d be allowed to poke around the human brain and see what other effects he might generate. A professor eventually persuaded him that it was insane to go through the misery of acquiring a medical degree unless he actually wanted to be a doctor. But it was the start of a pattern: seizing on some idea or ambition with great enthusiasm only to abandon it in disappointment. “I’ve always felt ideas were a dime a dozen,” he said. “If you had one that didn’t work out, you should not fight too hard to save it, just go find another.”
In an ordinary society it is unlikely that anyone would ever have discovered the fantastic practical usefulness of Danny Kahneman. Israel wasn’t a normal society. Graduating from Hebrew University—which somehow bestowed upon him a degree in psychology—Danny was required to serve in the Israeli army. Gentle, detached, disorganized, conflict-avoiding, and physically inept: Danny wasn’t anyone’s idea of a soldier. Only twice did he come close to having to fight, and both instances remained, to him, vividly memorable. The first time came when the platoon that he and several others commanded was ordered to attack an Arab village. Danny’s platoon was meant to circle around the village and ambush any Arab forces. The year before, after an Israeli army unit had massacred Arab women and children, Danny and his friend Shimon Shamir had discussed what they would do if they were ordered to kill Arab civilians. They’d decided that they would refuse the order. Here was the closest Danny would come to being given that order. “We were not supposed to go into the village,” he said. “The other officers were given their orders. And I listened—and they were never told to kill civilians. But they were never told how not to kill civilians. And I couldn’t ask the question—because it wasn’t my mission.” In the event, his own mission was aborted and his unit withdrawn before it came anywhere near to shooting at anyone—and only later did he learn why. The other platoons had walked into an ambush. The Jordanian army had been waiting for them. Had he not withdrawn, “We would have been butchered.”
The other time, he was sent one night to lay ambushes for the Jordanian army. He had three squads in his platoon. He led each of the first two squads to their ambush sites and left subordinates in charge of them. The third, on the Jordanian border, he led himself. To find the border, his commanding officer (a poet named Haim Gouri) told him, he should walk until he reached a sign: Frontier. Stop. In the dark, Danny missed the sign. As the sun rose, what he saw instead was an enemy soldier, on a hill, with his back to him: He’d invaded Jordan. (“I nearly started a war.”) The stretch of land beneath the hill in front of them, he saw, was ideally suited for Jordanian snipers looking to pick off Israeli soldiers. Danny turned to sneak his patrol back into Israel, but then he noticed that one of his men was missing his pack. Imagining the dressing-down he’d receive for leaving a pack in Jordan, he and his men crept around the fringes of the kill zone. “It was incredibly dangerous. I knew how stupid it was. But we would stay until we found it. Because I could hear the first question, ‘How could you leave that pack?’ That has stayed with me: the idiocy of it.” They found the pack, then left. Upon his return, his superiors admonished him, but not about the backpack. “They said, ‘Why didn’t you shoot?’”
The army jolted him out of his usual self-assigned role of detached observer. His year as a platoon commander, Danny said later, “removed the remaining traces of the pervasive sense of vulnerability and physical weakness and incompetence which I had had in France.” But he wasn’t born to shoot at people. He wasn’t really suited to army life, either, but the army forced him to be suitable. They assigned him to the psychology unit. The chief feature of the Israeli army’s psychology unit in 1954 was that it had no psychologists. Upon joining it, Danny found that his new boss—the Israeli army’s chief of psychological research—was a chemist. So Danny, a twenty-year-old refugee from Europe who had spent a meaningful amount of his life in hiding, found himself the Israel Defense Forces’ expert on psychological matters. “He was thin, ugly, and very clever,” recalls Tammy Viz, who served with Danny in the psychology unit. “I was nineteen and he was twenty-one, and I think he flirted with me and I was so dumb I didn’t know it. He was not a normal guy. But people liked him.” They also needed him—though how much they surely did not immediately appreciate.
The new nation faced a serious problem: how to organize a madly diverse population into a fighting force. In 1948, David Ben-Gurion had declared Israel open to any Jew who wished to immigrate. Over the next five years, the state accepted more than 730,000 immigrants from different cultures, speaking different languages. Many of the young men entering the new Israel Defense Forces already had endured unspeakable horrors—everywhere you turned, you found people with numbers tattooed on their arms. Mothers stumbled unexpectedly upon their own children, who they thought had been murdered by the Germans, on the streets of Israeli cities. No one was encouraged to speak about what he’d experienced in war. “People who had post-traumatic stress disorder were considered weaklings,” as one Israeli psychologist put it. Part of the job of being an Israeli Jew was to at least pretend to forget the unforgettable.
Israel was still less a nation than a fort, and yet its army was in a state of barely controlled chaos. The soldiers were poorly trained, the units poorly coordinated. The head of the tank division didn’t even speak the same language as most of his men. In the early 1950s there was no formal war between Arabs and Jews, but the senseless metronomic violence exposed vulnerabilities in the Israeli military. The soldiers tended to cut and run at the first sign of trouble, for instance; and the officers tended to lead from behind. The infantry staged a succession of failed night raids on Arab outposts, during which Israeli troops got lost in the dark and never reached their targets. In one case, after a unit sent out to stage an attack spent the night wandering around in circles, the platoon commander had simply shot himself. When they managed to engage the enemy, the results were often disastrous. In October 1953, an Israeli unit that may or may not have been given instructions not to harm civilians had raided a Jordanian village and killed sixty-nine people, half of them women and children.
Since the First World War, the job of assessing and sorting young conscripts into armies had fallen to psychologists, mainly because some ambitious psychologists had talked the U.S. Army into giving them the job. Still, if you need to sort tens of thousands of young men quickly into an efficient fighting force, it’s not immediately obvious that you also need a psychologist, and even less obvious when the only psychologist at hand is a twenty-one-year-old graduate of a two-year program who has more or less taught himself. Danny himself was surprised they asked him to do it, and did not feel equipped for the job. And he’d already seen the difficulty of trying to figure out which person was suited to which job when his superiors had asked him to evaluate candidates for officer training school.