Abstract

Humans are extremely prosocial and there are many possible explanations for how we came to be this way. Some have suggested that commitments explain the evolution of human prosociality. Commitments can serve to secure mutually beneficial interaction in the face of short-term incentives to cheat. In this paper, I have two aims. First, I argue that commitment not only applies to familiar practices such as promising but also explains small-scale collaboration among humans as early as two million years ago. In particular, it explains the stability of group hunting. In doing so, I provide a precisification of the concept of commitment. Second, I argue that earlier, non-linguistic forms of commitment can act as an evolutionary scaffold for more complex forms. As such, I will demonstrate how commitment can be understood to have coevolved with human cooperation. The coevolution of commitment and cooperation over our evolutionary history is, I suggest, a crucial part of the explanation of modern human prosociality.