Jonah Lehrer in The NewYorker. HereDaniel Kahneman, a Nobel Prize-winning psychologist and the author of the new book “Thinking, Fast and Slow,” changed the way people think about thinking by asking them questions. They weren’t trick questions, either. Instead, Kahneman relied almost exclusively on straightforward surveys, in which he described various scenarios. Here’s a sample:
The U.S. is preparing for the outbreak of an unusual Asian disease, which is expected to kill 600 people. Two alternative programs to combat the disease have been proposed. If program A is adopted, 200 people will be saved. If program B is adopted, there is a one-third probability that 600 people will be saved and a two-thirds probability that no people will be saved. Which of the two programs would you favor?
When Kahneman put this question to a few hundred physicians, seventy-two per cent chose option A, the safe-and-sure strategy. Most doctors would rather save a certain number of people for sure than risk the possibility that everyone might die.
Now consider this scenario:
The U.S. is preparing for the outbreak of an unusual Asian disease, which is expected to kill 600 people. Two alternative programs to combat the disease have been proposed. If program C is adopted, 400 people will die. If program D is adopted, there is a one-third probability that nobody will die and a two-thirds probability that 600 people will die. Which of the two programs would you favor?
The two different hypotheticals, of course, examine identical dilemmas: saving one-third of the population is the same as losing two-thirds. And yet, doctors reacted very differently depending on how the question was framed. When the possible outcomes were stated in terms of deaths (and not survivors), physicians were suddenly eager to take chances: seventy-eight per cent chose option D.
Why are doctors so inconsistent? Kahneman and his longtime collaborator, Amos Tversky, explained these contradictory responses in terms of loss aversion, or the fact that losses hurt more than gains feel good. In fact, people hate losses so much that merely framing a choice in terms of a potential loss can shift their preferences. Like those physicians, people are suddenly willing to risk losing everything if there’s a chance they might lose nothing.
Although our dislike of losses might seem obvious—“You need to have studied economics for many years before you’d be surprised by my research; it didn’t shock my mother at all,” Kahneman says—the discovery of loss aversion proved to be an important refutation of human rationality.