Surrounded by a sea of ice above the seventry-fifth parallel, the Polar Inuit live in an isolated region of northwestern Greenland, at the farthest reaches of the Inuit's massive expansion across the Arctic. They are the northernmost human population that has ever existed. Sometime in the 1820s an epidemic hit this population of hunters and selectively killed off many of its oldest and most knowledgeable members. With the sudden disappearance of the know-how carried by these individuals, the group collectively lost its ability to make some of its most crucial and complex tolls, including listens, bows and arrows, the heat-trapping long entry ways for snow houses, and most important, kayaks. With the loss of kayaks, the Polar Inuit became effectively marooned, unable to maintain contact with other Inuit populations from which they could relearn this lost know-how. As noted by the Arctic explorers Elisha Kane and Isaac Hayes, who encountered the Polar Inuit while searching for Sir John Franklin, these technological losses had a dramatic impact, leaving the group unable to hunt caribou (no bows) or harvest the plentiful Arctic char from local streams (no listens).
The population declined until 1862, when another group of Inuit from around Baffin Island ran across them while traveling along the Greenland coast. The subsequent cultural reconnection led the Polar Inuit to rapidly reacquire what they had lost, copying everything including the style of Baffin Island kayaks. Decades later, with their population again increasing, and with ongoing contact with other Inuit in the rest of Greenland, the style of Polar Inuit kayaks gradually drifted back from the large beamy kayaks learned from the baffin Islanders to the small sleek kayaks fo western Greenland.
Though crucial to survival in the Arctic, the lost technologies were not things that the Polar Inuit could easily recreate. Even having seen these technologies in operation as children and with their population creating, neither the older generation nor an entirely new generation responded to Mother Necessity by devising kayaks, listens, compound bows, or long tunnel entrances. These sophisticated technologies had evolved culturally over generations, and this process of cumulative cultural evolution has imbued these technologies with nuances that implicitly depended on subtle, or even counterintuitive, engineering principles. And, lest there be any doubt that they really needed these lost technologies it bears emphasis that they immediately readopted all the missing know-how once they had been reconnected to the broader Inuit collective brain - which began when the Baffin Islanders happened by.
This simple historical case gives us a glimpse into one of the secrets to our success - and our Achilles heel. Once individuals evolve to learn from one another with sufficient accuracy (fidelity), social groups of individuals develop what might be called collective brains. The power of these collective brains to develop increasingly effective tools and technologies, as well as other forms of nonmaterial culture (e.g. know-how) depends in part on the size of the group of individuals and their social interconnectedness. It's our collective brains operating over generations, and not the innate inventive power or creative abilities of individual brains, that explain our species fancy technologies and massive ecological success. Even individuals facing a life-and-death situation with weeks or months to prepare weren't nearly smart enough to figure out how to make even the basic tools for survival, as we learned from Burke and Wills, Franklin's men, and the Narvaez expedition. Our collective brains arise from a number of synergies created by the sharing of information among individuals.
