Theory of Mind varies in the accuracy, speed, and effort of mental state inferences, but can rapidly improve with practice

Human social cognition is built on our capacity to think about other minds. Do people have a general capacity to infer the contents of other minds from observable behavior? Or is this capacity specialized for inferring certain mental states, while struggling with others? Using a novel paradigm, we tested people’s capacity to infer another person’s desires, beliefs, or visual experience across three logically equivalent tasks. Despite the logical equivalence, people were less accurate, slower, and reported expending more effort when inferring the content of others’ visual experience compared to inferring others' beliefs and desires (Experiments 1 and 2; N = 120 U.S. adults and N = 60 U.S. adults). However, additional training rapidly improved people’s capacity to infer others’ visual experience (Experiment 3; N = 60 U.S. adults). Our results show that different kinds of mental state inferences produce different performance signatures, which may relate to how frequently we need to make such inferences in daily life.