We encountered the term “theory of mind” in passing in the previous chapter in relation to apes. Now let me explain it more fully. It is a technical term that is widely used in the cognitive sciences, from philosophy to primatology to clinical psychology. It refers to your ability to attribute intelligent mental beingness to other people: to understand that your fellow humans behave the way they do because (you assume) they have thoughts, emotions, ideas, and motivations of more or less the same kind as you yourself possess. In other words, even though you cannot actually feel what it is like to be another individual, you use your theory of mind to automatically project intentions, perceptions, and beliefs into the minds of others. In so doing you are able to infer their feelings and intentions and to predict and influence their behavior. Calling it a theory can be a little misleading, since the word “theory” is normally used to refer to an intellectual system of statements and predictions, rather than in this sense, where it refers to an innate, intuitive mental faculty.

Ramachandran, V.S. The Tell-Tale Brain: A Neuroscientist’s Quest for What Makes Us Human. New York: W. W. Norton & Company, 2011.