Mounting evidence is making it apparent that cortisol rhythmicity exhibits nonlinear properties. This is immediately relevant to brain-mapping projects and, more importantly, may profoundly affect our overall understanding of human cooperative behavior. The relative importance of the emerging insights builds on an understanding that disruptions to cortisol rhythmicity underlie individuals’ response to stress, where efforts to restore stability at the cellular molecular level may involve activity which is highly structured and coordinated on massively different levels of scale, including individual and community behavior that increasingly displays a global reach. If we are correct in understanding that this comprehensive set of behavioral relationships depends on nonlinear properties as an organizing principle, then we have a powerful set of tools with which to creatively approach many important challenges facing the emergence of a global community. Chief among these is the need to dramatically improve human cooperation, where large gaps exist in our collective understanding of community behavior. Up to this point the implications for human cooperation arising from the discovery that cortisol rhythmicity displays nonlinear behavior have been unknown, and the mechanisms whereby nonlinear properties of these relationships impact behavior across levels of scale have not been identified. The following introduction explores the implications of this discovery. Specifically, we will explore how understanding nonlinear properties in the relationship between cortisol rhythmicity, other neurological activity, and the larger community (on successive levels of scale) can enable us to lay out a theoretical framework as well as to conceptualize specific tools with which we can first model and then design human systems that significantly improve cooperation on all levels. Read the full Project Rationale.