The human capacity for rational decisions hinges on modal judgment: the discernment of what could, has to, or cannot happen. This ability was proposed to be a late outcome of human cognitive development, contingent on the mastery of linguistic structures. Here, we show that preschool-age children are capable of sophisticated forms of modal…

Children often say that possible events are impossible, and only gradually come to see these events as possible. For instance, they often deny that people could do unusual things, like own a pet peacock, or immoral things, like stealing or lying. These possibility denials are surprising. For instance, children have first-hand experience with the…

Collaboration, the process by which individuals work together toward mutual benefits, is a core feature of human sociality. Capacities for collaboration emerge early in development and represent an important social competence. Yet, collaborative commitments can conflict with commitments to societal norms such as honesty and rule compliance, and…