We are on the tube and I inadvertently step on your toes. We look at each other and I say: "I'm sorry, I didn't intend to". Barry asks Larry why Harry didn't come to the party, and Larry says: "because he believed it would have been next week". In the wake of our social interactions, we talk about beliefs and intentions, as well as  indefinitely many other kinds of "mental states", to justify, explain and predict behaviours. These capacities, which we manifest in both linguistic and non-linguistic ways, have been variously named "folk psychology", "psychological reasoning", "theory of mind", "mindreading". But what does our knowledge of other minds consist in? Is it some sort of implicit theory, or rather an imaginative projection in other people's shoes? Is it primarily normative, and used for interpreting others, or is it primarily descriptive, and used for predicting behaviour? Is it necessary to speak a language for reasoning about mental states, or is it the other way round?

In this course, we will tackle these questions by investigating, in an interdisciplinary fashion, the emergence of psychological reasoning in childhood, in both typical and atypical development. Do children reason about intentions and beliefs even if they don't have a language? If yes, how? Can we find out experimentally?