Complexity and the evolution of the social brain

Our long-term goal is to understand the relationship between complex behaviors and complex brains. Here, we explore the effects of social organization, specifically monogamy versus polygamy, on the brains and behavior of African cichlid fishes. Since cichlids process social information visually, we began by behaviorally comparing the visual acuity of monogamous and polygamous fish. We then explored the next level, where social meaning is extracted from the sensory information, by comparing the size of the telencephalon and amygdalar homologue, area Dm. We also explored integrative brain areas and neuropeptides implicated in social behavior by comparing the number of AVT-immunoreactive cells in the preoptic area of the brain. Finally, we explored the role of social experience in visual behavior in a monogamous species by comparing isolated fish with those from a normal social group. This paper details the preliminary results of our investigation.