Brain size in primates is predicted by diet, an analysis by a team of New York University anthropologists indicates. These results call into question “the social brain hypothesis,” which has posited that humans and other primates are big-brained due to factors pertaining to sociality. The findings, which appear in the journal Nature Ecology and Evolution, reinforce the notion that both human and non-human primate brain evolution may be driven by differences in feeding rather than in socialization. “Are humans and other primates big-brained because of social pressures and the need to think about and track our social relationships, as some have argued?” asks James Higham, an assistant professor in NYU’s Department of Anthropology and a co-author of the new analysis. “This has come to be the prevailing view, but our findings do not support it—in fact, our research points to other factors, namely diet.”
