Theory of mind is the ability to attribute mental states—beliefs, intents, desires, pretending, knowledge, etc.—to oneself and others. As originally defined, it enables one to understand that mental states can be the cause of—and thus be used to explain and predict—others’ behavior. Being able to attribute mental states to others and understanding them as causes of behavior means, in part, that one must be able to conceive of the mind as a “generator of representations” and to understand that others’ mental representations of the world do not necessarily reflect reality and can be different from one’s own. It also means one must be able to maintain, simultaneously, different representations of the world. It is a ‘theory’ of mind in that such representations are not “directly observable”. Many other human abilities—from skillful social interaction to language use—are said to involve a theory of mind.
Theory of mind appears to be an innate potential ability in humans, but one requiring social and other experience over many years to bring successfully to adult fruition. It is probably a continuum, in the sense that different people may develop more, or less, effective theories of mind, varying from very complete and accurate ones, through to minimally functional. It is often implied or assumed that this does not merely signify conceptual understanding “other people have minds and think,” but also some kind of understanding and working model that these thoughts and states and emotions are real and genuine for these people and not just ungrounded names for parroted concepts. Empathy is a related concept, meaning experientially recognizing and understanding the states of mind, including beliefs, desires and particularly emotions of others without injecting your own, often characterized as the ability to “put oneself into another’s shoes.”