This article proposes a recontextualization of the conception of free will in terms of social events rather than in mental experiences. My objective is to demonstrate that the behavior of human social groups composed of individuals freely interacting among each other exhibits well-defined patterns that can precisely be described by a physics formalism. Although not directly approaching the nature of the mental states involved in each individual behavior, I argue that the emergence of organized social behavior occurs under the influence of free will. First, I briefly introduce the concept of self-organized criticality (SOC) that is central to the understanding of my argument. Second, I review experimental data showing that normal individuals and patients with different mental disorders exhibit a social behavior pattern compatible with the presence of SOC. Third, a brief discussion about the functioning of free will in psychiatric disorders is presented. Finally, the implications for psychological and social theories of including free will in this kind of physical model are discussed.