Theory of Planned Behavior

Conceptual Framework

According to the theory, human social behavior is guided by three kinds of considerations: beliefs about the behavior's likely positive and negative outcomes, known as behavioral beliefs; beliefs about the normative expectations of others, called normative beliefs; and beliefs about the presence of factors that may facilitate or impede performance of the behavior, termed control beliefs. For example, people may believe that the behavior of exercising, among other things, improves physical fitness and is tiring (behavioral beliefs), that their family and friends think they should exercise (normative beliefs), and that time constraints make it difficult to exercise (control belief). Taken together, the total set of behavioral beliefs produces a favorable or unfavorable attitude toward the behavior; the total set of normative beliefs results in perceived social pressure to perform or not to perform the behavior, or subjective norm; and, in their totality, control beliefs give rise to a sense of self-efficacy or perceived control over the behavior.

Attitude toward the behavior, subjective norm, and perceived behavioral control jointly lead to the formation of a behavioral intention. The relative weight or importance of each of these determinants of intention can vary from behavior to behavior and from population to population. However, as a general rule, the more favorable the attitude and subjective norm are, and the greater the perceived behavioral control is, the stronger is the person's intention to perform the behavior in question. Finally, people are expected to carry out their intentions when the appropriate opportunity arises. However, successful performance of a behavior depends not only on a favorable intention but also on a sufficient level of volitional control, that is, on possession of requisite skills, resources, opportunities, and the presence of other supportive conditions. Because many behaviors pose difficulties of execution, the TPB adds perceived behavioral control to the prediction of behavior. To the extent that perceived behavioral control is accurate, it can serve as a proxy of actual control and can, together with intention, be used to predict behavior.

Beliefs play a central role in the TPB, especially those salient behavioral beliefs that are most readily accessible in memory. In applications of the theory, these salient beliefs are elicited in a free-response format by asking a representative sample of respondents to list the advantages and disadvantages of performing [Page 988]a behavior of interest (behavioral beliefs), to list the individuals or groups who approve or disapprove of performing the behavior (normative beliefs), and to list the factors that facilitate or inhibit performance of the behavior (control beliefs). The most frequently emitted behavioral, normative, and control beliefs are assumed to be the salient beliefs in the population and to determine prevailing attitudes, subjective norms, and perceptions of behavioral control. These salient beliefs are focused on the particular behavior of interest, and they serve as the fundamental explanatory constructs in the theory. More general factors, such as personality traits, gender, education, intelligence, motivation, or broad values are assumed to influence behavior only indirectly by their effects on salient beliefs. Assume, for example, that women are found to drink less alcohol than men. The TPB would explain this gender effect by predicting that men hold more favorable behavioral, normative, or control beliefs about drinking than women do.

...