Novel Theory of Mind Task Demonstrates Representation of Minds in Mental State Inference

Theory of mind (ToM), the ability to represent the mental states of oneself and others, is argued to be central to human social experience, and impairments in this ability are thought to underlie several psychiatric and developmental conditions. To examine the accuracy of mental state inferences, a novel ToM task was developed, requiring inferences to be made about the mental states of ‘Targets’, prior participants who took part in a videoed mock interview. Participants also made estimates of the Targets’ personality traits. These inferences were compared to ground-truth data, provided by the Targets, of their true traits and mental states. Results from 55 adult participants demonstrated that trait inferences were used to derive mental state inferences, and that the accuracy of trait estimates predicted the accuracy of mental state inferences. Moreover, the size and direction of the association between trait accuracy and mental state accuracy varied according to the trait—mental state combination. The accuracy of trait inferences was predicted by the accuracy of participants’ understanding of trait covariation at the population level. Findings are in accordance with the Mind-space theory, that representation of the Target mind is used in the inference of their mental states.