Mental files: Developmental integration of dual naming and theory of mind

Abstract We use mental files theory to provide an integral theory of children’s diverse dual naming problems and why these problems are overcome when children pass the false belief test. When an object is encountered under different appearances or given different verbal labels, two distinct representations (mental files) may be deployed for that single object. The resulting files refer to the same object but capture different perspectives on the object. Such coreferential files can thus be used to represent people’s differing perspectives (e.g., belief). Typically the existence of different files indicates the existence of two separate objects. To mark that only a single object is involved, coreferential files need to be linked. Development of the ability to link files provides a powerful developmental explanation for success on dual labelling and perspective tasks at the same age, around 4 years: processing identity statements, overcoming mutual exclusivity (accepting different labels for an object), visual perspective taking, and understanding differences of belief. Mental files also provide a new framework for understanding conceptual pacts and their relation to mutual exclusivity in children and adults.