North Atlantic

The North Atlantic enters the account as the immense, uncertain setting of the 1968 disappearance of the U.S. submarine Scorpion. Its scale makes the search seem nearly impossible, but it also gives the book its culminating example of collective judgment: fragments of knowledge, independently elicited and combined, locate what no individual participant could pinpoint alone.

The Search Problem

In May 1968, Scorpion disappeared while returning to Newport News after a tour of duty in the North Atlantic. The navy knew the submarine’s last reported location, but not what had happened to it or how far it might have traveled after its final radio contact. The initial search area was a circle twenty miles wide, extending thousands of feet down. The sea’s breadth and depth turned missing information into a practical obstacle: there was no clear event to follow, only a large space in which the submarine might be.

The obvious approach seemed to be to find three or four leading experts on submarines and ocean currents and ask them where to search. Naval officer John Craven instead treated the problem as one of assembling partial judgments. The North Atlantic was not merely a backdrop to the loss; its opacity made a method for combining uncertain information necessary.

Craven’s Collective Estimate

Craven devised alternative scenarios for what might have happened to Scorpion and gathered men with varied expertise, including mathematicians, submarine specialists, and salvage men. Rather than having them deliberate together toward a shared answer, he asked each to estimate the likelihood of the scenarios. Their judgments took the form of wagers, with bottles of Chivas Regal as prizes. Participants bet on such distinct questions as why the submarine ran into trouble, its speed as it descended, and the steepness of its descent.

No single bet could identify the submarine’s location. Craven’s method depended on combining the estimates into a composite account of how Scorpion had died, then using Bayes’s theorem to calculate a final location. That location did not match the choice of any one participant: it was a group judgment assembled from their separate contributions, not the answer of the shrewdest individual or a consensus reached through discussion.

The Search’s Result and Significance

Five months after Scorpion disappeared, a navy ship found it 220 yards from the location Craven’s group had estimated. The result gives the North Atlantic episode its force in the book’s argument: although the participants possessed only scraps of information, their combined estimate proved remarkably accurate.

The account closes the Introduction by returning to its earlier example of a group estimating an ox’s weight. The two problems differ enormously in scale and complexity, but the underlying principle is presented as the same. In the North Atlantic search, no one knew the cause of the sinking, the submarine’s speed, or the steepness of its descent; the assembled judgments nevertheless produced a location the group had not individually envisioned. The ocean’s vastness thus frames a demonstration of collective intelligence under severe uncertainty.