Foreign thinker
Philip E. Tetlock
Philip E. TetlockPolitical psychology and the science of forecastingCanadian-Americanb. 1954
Life and Thought
Philip Tetlock is a Canadian-American political psychologist and professor at the University of Pennsylvania, known for decades-long research into the accuracy of expert political and economic judgment. In his books Expert Political Judgment and Superforecasting, he showed that most experts' predictions are not much better than chance, while identifying systematic thinking habits shared by a group of unusually accurate forecasters he called "superforecasters." He co-led the Good Judgment Project, a major geopolitical forecasting tournament run for a U.S. intelligence research agency.
Philip Eyrikson Tetlock was born on March 2, 1954, in Toronto, Canada. He earned his BA and MA in psychology from the University of British Columbia and completed his PhD in psychology at Yale University in 1979 under the supervision of Phoebe Ellsworth. Over his academic career he has held positions at Ohio State University and the University of California, Berkeley, before joining the University of Pennsylvania, where he now holds the Annenberg University Professorship, jointly appointed at the Wharton School and the School of Arts and Sciences.
Tetlock's central reputation rests on a two-decade research program tracking the accuracy of political and economic experts' predictions, published as Expert Political Judgment: How Good Is It? How Can We Know? (2005). Following thousands of forecasts by specialists over many years, he found that, on average, their predictive accuracy was not meaningfully better than chance. Drawing on Isaiah Berlin's well-known "hedgehog and fox" metaphor, he distinguished between "hedgehog" thinkers, who explain everything through one grand overarching idea and tend to be weaker forecasters, and "fox" thinkers, who hold multiple perspectives and a more flexible approach and tend to forecast more accurately.
Building on this line of research, Tetlock, together with Barbara Mellers, led the Good Judgment Project, run within a large geopolitical-forecasting tournament sponsored by the U.S. Intelligence Advanced Research Projects Activity (IARPA) from 2011 to 2015. The project identified a group of volunteer forecasters whose accuracy significantly exceeded that of professional intelligence analysts — a group Tetlock termed "superforecasters." The project's findings were published in the bestselling Superforecasting: The Art and Science of Prediction (2015), co-written with Dan Gardner, which outlined the shared traits of successful superforecasters: probabilistic thinking, continual belief-updating in light of new evidence, teamwork, and avoidance of ideological rigidity.
Tetlock has published more than ten books and numerous scholarly articles on judgment, decision-making, and counterfactual reasoning in politics, including Counterfactual Thought Experiments in World Politics and Unmaking the West: What-If Scenarios that Rewrite World History. He was elected a member of the American Philosophical Society in 2019 and remains an influential figure in decision science, risk assessment, and evidence-based policymaking.
