Octopus Brains Challenge the Social Theory of Intelligence Evolution

For decades, scientists believed that large brains were nature's answer to the demands of social life — that managing alliances, hierarchies, and relationships was what drove intelligence to flourish. Now, a study of 79 cephalopod species published in iScience quietly dismantles that assumption: octopuses, squid, and cuttlefish have evolved remarkably large brains while living almost entirely alone, suggesting that a complex environment, not a complex society, may be equally capable of growing a mind. The finding does not erase what came before, but it opens the door to a more plural understan