One personal in nature and the other reflecting social influence

Since we are interested in understanding human behavior, not merely in predicting it, we must next identify the determinants of intentions. According to the theory of reasoned action, a person's intention is a function oftwo basic determinants; one personal in nature and the other reflecting social influence. The personal factor is the individual's positive or negative evaluation of performing the behavior; this factor is termed attitude toward the behavior. Note that the theory of reasoned action is concerned with attitudes toward behaviors and not with the more traditional attitudes toward objects, people, or institutions. The second determinant of intention is the person's perception of the social pressures put on him to perform or not perform the behavior in question. Since it deals with perceived prescriptions, this factor is termed subjective norm. Generally speaking, people intend to perform a behavior when they evaluate it positively and when they believe that important others think they should perform it. (Ajzen 1985, p. 12)

Ajzen, Icek. 1985. “From Intentions to Actions: A Theory of Planned Behavior.” In Action Control: From Cognition to Behavior, edited by Julius Kuhl and Jürgen Beckmann, 11–39. Berlin, Heidelberg: Springer Berlin Heidelberg. http://dx.doi.org/10.1007/978-3-642-69746-3_2.