How physical information is used to make sense of the psychological world

How do people make sense of other people, who are simultaneously psychological beings and physical objects? Across the cognitive sciences, researchers have studied theory of mind (making sense of other people’s behaviors in terms of their mental states, or ‘naive psychology’) and physical reasoning (making sense of physical events in terms of their underlying mechanics and dynamics, or ‘naive physics’), as two separate processes. In this paper, we describe two key ways in which psychological reasoning depends on physical reasoning. First, people represent animate agents as objects who act on and in a physical world. Second, people use physical knowledge in order to make inferences about other minds, including what other people want, feel, and know, how hard they are trying, and how much danger they are in. We review research from developmental psychology and cognitive neuroscience, which provides evidence for the intersection of these two systems, and Bayesian computational models of theory of mind, which articulate a formal hypothesis about how these two systems work together. We propose that from early in human development, people solve a ‘commonsense mind-body problem’ by dedicating two distinct systems for reasoning about ethereal minds and physical bodies, grounded in a shared representation of the physical world.