Big Brains: A Deep Dive Into Cetacean Social Cognition and Behavior

Cetaceans are members of infraorder Cetacea, a subgroup of Artiodactyls (even-toed ungulates) that have adapted to a fully aquatic environment. The purpose of this thesis is to review and synthesize the research on the unique and special characteristics of the central nervous systems (brains) of cetaceans, with a particular focus on social cognition and behavior which may be influenced by these characteristics. Cetacean brains differ from the brains of other mammals—and animals in general—in many ways; the most significant of these differences for social cognition include, but are not limited to: bigger brains, higher relative and absolute neuron counts, unique auditory neural regions, divergent cortical layering; high investment in neural connectivity, a highly different prefrontal cortex; and in some cases, a specialized pattern of cerebellum evolution. The many unique qualities of cetacean brains are likely explained by their particular evolutionary history and pressures, and also help to explain some of the relational and social patterns that are so characteristic of cetaceans, including perceptions of self and others, (including communicative behavior, and gazing and locating to form and maintain connections), object permanence, imitation, vocal learning, and their unique sleep patterns. The analysis concludes with hopes for the future of research and our understanding of the neural substrates for cognition and social behavior in cetaceans— and in general