Theory of Mind

The ability of an individual to impute (attribute, assign) mental states to himself and to others (either to conspecifics or to other species as well). A system of inferences of this kind is properly viewed as a theory because such states are not directly observable, and the system can be used to make predictions about the behaviours or others. An individual may infer, for example, purpose or intention, as well as knowledge, belief, thinking, doubt, guessing, pretending, liking and so forth.

Reference:
Premack, D., & Woodruff, G. (1978). Does the chimpanzee have a theory of mind?. Behavioral and Brain Sciences, 1(04), 515-526. doi: 10.1017/S0140525X00076512.