The psychologist who transformed economics

Daniel Kahneman upended the field of economics without ever taking an economics class. The psychologist injected the mathematical subject with behavioral science in the 1970s, showing how mental biases and overconfidence warp our decisionmaking. He earned a Nobel Prize in economics in 2002 for his insights into human fallibility—a subject he could never exhaust. “We would all like to have a warning bell that rings loudly whenever we are about to make a serious error,” he wrote, “but no such bell is available.” Born while his mother was visiting Tel Aviv, Kahneman was raised in Paris until World War II. Forced to wear the yellow star under Nazi occupation, his family fled to the countryside, hiding in barns and chicken coops. After the war, he landed in what was then British-controlled Palestine. Drafted into the Israeli Defense Forces in 1954, the psychology graduate was tasked with assessing potential officers— something his unit got wrong so often that it set Kahneman on the path of investigating why predictions fail, said The New York Times. After earning his Ph.D. he taught at Hebrew University and Princeton. “Mild-mannered and self-effacing,” he sought out “adversaries as well as colleagues” to strengthen his ideas. Kahneman spent decades collaborating with Stanford psychologist Amos Tversky on theories that led to rethinking everything from medical malpractice to evaluating baseball talent. “Tversky was the life of the party,” said The Washington Post. “Kahneman never even went.” Still, his insights into human inconsistency became mainstream wisdom and made his 2011 book, Thinking, Fast and Slow, a best-seller. Kahneman frequently drew attention to his own mistakes, “Being wrong,” he once told a fellow psychologist, “is the only way I feel sure I’ve learned anything.”