Cephalopods challenge the social brain rule: ecology drives big brains
New research argues big brains aren’t solely a product of social living. An analysis of 79 cephalopod species shows habitat and ecological complexity better predict brain size than sociality, with bottom-dwelling, shallow-water species having larger brains even when solitary. The findings support the cultural brain hypothesis, which posits brains evolve to store and process information learned either socially or asocially, implying multiple evolutionary routes to intelligence beyond social structures. While correlation cannot prove causation, the study suggests ecology as a primary driver of cephalopod brain size and invites reevaluation of brain-evolution theories.
