The Key to Accurately Predicting the Future: Know When to Change Your Mind

Photo: H. Armstrong Roberts/ClassicStock/Getty Images

Predicting the future seems like something best left to pseudoscience — fortune tellers, psychics, horoscopes, that kind of thing. But think about it: Most people could stand to improve their ability to guess at what’s coming next, whether it be in their careers or their personal relationships. And for some in particular — economists, intelligence officers, even meteorologists — it’s a crucial skill to have.

As such, forecasting, as it’s called, is the domain of serious scientific study, and one of the leaders in this field is Philip Tetlock, of the University of Pennsylvania’s Wharton School. Recently, Tetlock did an interview with The Wall Street Journal in which he noted one of the most important features of accurate forecasting: the willingness to change your mind. Consider this exchange, between Tetlock and WSJ columnist Jason Zweig:

MR. ZWEIG: Your work suggests that you want people to update their forecasts and not be too slow to change their minds, right?

MR. TETLOCK: Yes. A key defining feature of the best forecasters is that they update often, and they typically update by relatively small increments.

Often, Tetlock explained, the problem comes when someone knows too much about the thing they’re trying to predict. “I was talking once to John McLaughlin, former director of the CIA, about the end of the Cold War period, and he was remarking that the analysts who were slowest to recognize that East Germany was disintegrating were the people who had been on the case for 20 years,” he told Zweig. In contrast, the non-experts caught on faster, something that squares with the scientific evidence, which “attests to the power of preconceptions to grip us and make it hard for us to be timely belief updaters,” Tetlock added.

The best of the best at accurately divining the metaphorical tea leaves, by the way, are called superforecasters, and Tetlock published a book about these individuals last fall, Superforecasting: The Art and Science of Prediction. In an interview with Science of Us, he credited superforecasters’ skill not to their superior intelligence, but to their open-mindedness, as their future-telling talent seems to rely at least in part on their ability to make small, but frequent, changes to their predictions. The best strategy for knowing what’s ahead, in other words, is being absolutely sure that you can never be absolutely sure.

To Guess the Future, Be Ready to Change Your Mind