The assumption that individuals are behaving rationally can, at times, usefully constrain predictions of individual and collective behavior. However, success in predicting human and group behavior will often require relaxing this assumption of rationality, instead employing evolutionary, neural, and cognitive constraints. One particularly important form of neural and cognitive constraint is that interacting individuals each possess a network of concepts, and communities are accordingly social networks of neural networks. The structured nature of human conceptual systems suggests that communicating is better modeled as a process of aligning conceptual systems rather than simply transmitting atomic beliefs. Communicating individuals can establish norms, conceptual structures, and rule systems that did not preexist prior to the communication process. For this reason, the dichotomy between rule-based and centralized groups versus self-organized and decentralized groups is false – one of the major activities that self-organized and decentralized groups engage in is the establishment of rules, laws, norms, leaders, and institutional hierarchies that will then govern their subsequent interactions.