The Undoing Project: A Friendship That Changed Our Minds

This chapter focuses on a paper that Danny and Amos wrote together that focused on the psychological factors that go into predictions. Aptly named “On the Psychology of Prediction,” this paper argued that people do not rely on statistical odds, or what they called “the calculus of chance,” but rather on mental rules of thumb—heuristics—that often lead to serious error.

To test their ideas, Danny and Amos ran a series of experiments in which people were asked to predict certain outcomes—the future of a student, for instance. Ultimately, their research on predictions seemed to reinforce much of their previous research. In essence, the human mind makes mistakes that are often caused by preconceived notions and biases. Danny and Amos argued that “the very factors that caused people to become more confident in their predictions also led those predictions to become less accurate” (202). Like when making any other judgment, the mind establishes internal rules when making predictions, and these rules often lead to systematic mistakes. The only way to improve the accuracy of predictions would be to challenge or revise the mind’s rules when predicting.

Just as Danny and Amos were strengthening their theories on prediction, and just as the field of psychology was taking notice of their collaborative work, the armies of Egypt and Syria launched an attack on Israel in 1973, which meant that Danny and Amos had to prepare to be called back into military duty.