Aggregating the judgment of many consistently beats the accuracy of the average member of the group, and is often as startlingly accurate as Galton’s weight-guessers. The collective judgment isn’t always more accurate than any individual guess, however. In fact, in any group there are likely to be individuals who beat the group. But those bull’s-eye guesses typically say more about the power of luck—chimps who throw a lot of darts will get occasional bull’s-eyes—than about the skill of the guesser. That becomes clear when the exercise is repeated many times. There will be individuals who beat
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