A formal group theory-based model in primates for studying interactive social behavior and its dysfunction Unlike most forms of solitary behavior that have been broadly studied through animal models, remarkably little is known about the single-neuronal or causal bases of interactive social behavior and its dysfunction. One of the major reasons for this limitation is the general lack of animal models and framework for studying the neural substrates of social behavior whereby two or more individuals interact in real-time and in a way that is amenable to neuronal analysis or perturbation techniques. This limited understanding impacts not only wide spanning fields of study such as ecology, neurology and psychology but also our ability to treat conditions such as autism-spectrum disorder in which social behavior is prominently affected. Primates are highly social animals that share many behaviors in common with humans and can serve as a potential model for understanding the basic elements that underlie interactive behavior. In this proposal, we aim to build on our team’s unique combined experience with jointly interacting primate pairs and groups, social theory, multi-site neuronal recordings and time-resolved neuromodulation techniques to begin identifying some of the basic neuronal encoding components of interactive behaviors, their representation within and across cortical populations, and their dynamic across short and long temporal scales. Using social group theory in primates together with population modeling and perturbation techniques, we will investigate core social constructs such as agency identity, group dynamics and decision strategies essential for effective social behavior. We will also test specific hypotheses on the causal contribution that distinct frontal, temporal and parietal areas play in social interaction and what exact aspects are involved. Taken together, this proposal aims to provide a formal theory- based model by which to begin investigating interactive social behavior at the single-neuronal, population and circuit-based levels. We believe that this is an essential new line of investigation and has the potential to open up a poorly explored but important field within neuroscience and from which to begin testing neuro-modulatory interventions aimed at treating psychosocial disorders.