Abstract

What is the distribution of cognitive ability within the animal kingdom? It would be egalitarian to assume that variation in intelligence is everywhere clinal, but examining trends among major phylogenetic groups, it becomes easy to distinguish high-performing ‘generalists’ – whose behavior exhibits domain-flexibility – from ‘specialists’ whose range of behavior is limited and ecologically specific. These generalists include mammals, birds, and, intriguingly, cephalopods. The apparent intelligence of coleoid cephalopods (squids, octopuses, and cuttlefish) is surprising – and philosophically relevant – because of our independent evolutionary lineages: the most recent common ancestor between vertebrates and cephalopods would have been a small wormlike organism, without any major organizational structure to its nervous system. By identifying the cognitive similarities between these organisms and vertebrates, we can begin to derive some general principles of intelligence as a biological phenomenon. Here, I discuss trends in cephalopod behavior and surrounding theory, and suggest their significance for our understanding of domain-general cognition and its evolution