John Craven (1924-2015) was a US Navy officer and scientist who applied systems analysis and probability theory to naval problems. He is best known in the book for leading the effort to locate the missing submarine Scorpion in 1968. Craven gathered a diverse team of experts, asked each to estimate where the submarine might be, and then aggregated their guesses. The averaged prediction proved astonishingly accurate, as the wreck was located within a few hundred yards. Craven’s method became a striking demonstration of the crowd’s accuracy when diversity and independence are preserved, reinforcing Surowiecki’s claim that groups often surpass individual experts.

Francis Galton (1822-1911) was a British scientist known for his work in statistics, psychology, and heredity. A cousin of Charles Darwin, Galton was influential in shaping ideas about human intelligence and was an early proponent of eugenics, which has since been widely discredited for its unethical assumptions. In The Wisdom of Crowds, Galton appears as the unlikely discoverer of collective intelligence: After observing a weight-guessing contest at a county fair in 1906, he calculated that the crowd’s average guess was almost exactly correct. Although Galton himself believed in the superiority of elites, his ox-weighing experiment became one of the clearest illustrations of Surowiecki’s thesis that groups can outperform individual experts when conditions of diversity, independence, and decentralization are met.