Davis (1983) a multi-component response
(a) perspective-taking, the ability to adopt the viewpoint of another person;
(b) fantasy, the ability to transpose oneself into the feelings of a fictitious character;
(c) empathic concern, feelings of concern for another person; and
(d) personal distress, self-oriented feelings of distress.
He created the, Interpersonal Reactivity Index (IRI).