Folktale transmission in the Arctic provides evidence for high bandwidth social learning among hunter-gatherer groups

There exist striking resemblances in the stories of ethnolinguistic groups separated by vast geographic distances, with nearby groups having the most in common. The causes of these geographic associations are uncertain. Here we use method and theory from population genetics to examine cultural transmission in folktale inventories of 18 hunter-gatherer groups spread across 6000 km of Siberia, Alaska, Canada, and Greenland. We find that linguistic relatedness and geographic proximity independently predict overlap in folktale inventories, which provides evidence for both vertical transmission down cultural lineages and horizontal transmission between groups. These results suggest that high-bandwidth social learning across group boundaries is a feature of traditional hunter-gatherers, which may help explain how complex cultural traditions can develop and be retained in ostensibly small groups.