Humans excel at both cooperation and competition. Disentangling the motivations and institutions of productive and antagonistic relationships is a major focus of the social and behavioral sciences. How are individual, self-interested goals integrated with group-level endeavors that reward cooperation? What are the costs and benefits to individuals across the socioeconomic spectrum for participating in, or defecting from, cooperative endeavors? What mechanisms for encouraging and maintaining cooperation exist within any particular society, and how do those mechanisms evolve over time as a result of cumulative goal-seeking by individuals? Why does cooperation sometimes breakdown completely? Anthropologists have examined the human engagement with cooperation and competition over the long term of cultural evolution and are now focusing on “bottom-up” explanations for self-organization and group cooperation that counterbalance older models that stressed “top-down” leadership. This symposium explores the dynamics of sustaining large-scale cooperative endeavors through the socially cohesive aspects of ritual, warfare, labor, and taxation. Participants are interested in better defining the terms, appropriate units of analysis, and theoretical frameworks necessary for understanding the cultural and evolutionary dynamics of group cooperation. The session presents diverse case studies with an interest in applying archeological data to this issue of broad social concern.