Many coupled human-nature systems are characterized by complexities such as nonlinearities and heterogeneity. Less is known about how human decisions are made to affect such systems. This symposium, which incorporates case studies in three Asian national reserves/parks, centers on generalizing characteristics, driving forces, and related methodologies for understanding human decision-making and its consequences. Using social surveys, fieldwork, and different modeling approaches (e.g., agent-based modeling), three junior researchers explore how social norms and the hierarchical structure of human organizations or decisions may feed back into each other and affect human resource–utilization decisions, thus affecting habitat dynamics of these species. After that, their mentors and a few well-established outside researchers present general theoretical reflections on what theories and methods can be used to tackle human decisions and how such decisions lead to system changes. Our purposeful intermix of researchers from different career stages, study sites, and backgrounds aims to better fertilize the study of complex human-nature systems.