People represent mental states in terms of rationality, social impact, and valence: Validating the 3d Mind Model.

Humans can experience a wide variety of different thoughts and feelings in the course of everyday life. To successfully navigate the social world, people need to perceive, understand, and predict others' mental states. Previous research suggests that people use three dimensions to represent mental states: rationality, social impact, and valence. This 3d Mind Model allows people to efficiently "see" the state of another person's mind by considering whether that state is rational or emotional, more or less socially impactful, and positive or negative. In the current investigation, we validate this model using neural, behavioral, and linguistic evidence. First, we examine the robustness of the 3d Mind Model by conducting a mega-analysis of four fMRI studies in which participants considered others' mental states. We find evidence that rationality, social impact, and valence each contribute to explaining the neural representation of mental states. Second, we test whether the 3d Mind Model offers the optimal combination of dimensions for describing neural representations of mental state. Results reveal that the 3d Mind Model achieve the best performance among a large set of candidate dimensions. Indeed, it offers a highly explanatory account of mental state representation, explaining over 80% of reliable neural variance. Finally, we demonstrate that all three dimensions of the model likewise capture convergent behavioral and linguistic measures of mental state representation. Together, these findings provide strong support for the 3d Mind Model, indicating that is it is a robust and generalizable account of how people think about mental states.