Icek Ajzen

The theory of planned behavior

Research dealing with various aspects of* the theory of planned behavior (Ajzen, 1985, 1987) is reviewed, and some unresolved issues are discussed. In broad terms, the theory is found to be well supported by empirical evidence. Intentions to perform behaviors of different kinds can be predicted with high accuracy from attitudes toward the behavior, subjective norms, and perceived behavioral control; and these intentions, together with perceptions of behavioral control, account for considerable variance in actual behavior. Attitudes, subjective norms, and perceived behavioral control are shown to be related to appropriate sets of salient behavioral, normative, and control beliefs about the behavior, but the exact nature of these relations is still uncertain. Expectancy— value formulations are found to be only partly successful in dealing with these relations. Optimal rescaling of expectancy and value measures is offered as a means of dealing with measurement limitations. Finally, inclusion of past behavior in the prediction equation is shown to provide a means of testing the theory*s sufficiency, another issue that remains unresolved. The limited available evidence concerning this question shows that the theory is predicting behavior quite well in comparison to the ceiling imposed by behavioral reliability.

From Intentions to Actions: A Theory of Planned Behavior

There appears to be general agreement among social psychologists that most human behavior is goal-directed (e. g., Heider, 1958 ; Lewin, 1951). Being neither capricious nor frivolous, human social behavior can best be described as following along lines of more or less well-formulated plans. Before attending a concert, for example, a person may extend an invitation to a date, purchase tickets, change into proper attire, call a cab, collect the date, and proceed to the concert hall. Most, if not all, of these activities will have been designed in advance; their execution occurs as the plan unfolds. To be sure, a certain sequence of actions can become so habitual or routine that it is performed almost automatically, as in the case of driving from home to work or playing the piano. Highly developed skills of this kind typically no longer require conscious formulation of a behavioral plan. Nevertheless, at least in general outline, we are normally well aware of the actions required to attain a certain goal. Consider such a relatively routine behavior as typing a letter. When setting this activity as a goal, we anticipate the need to locate a typewriter, insert a sheet of paper, adjust the margins, formulate words and sentences, strike the appropriate keys, and so forth. Some parts of the plan are more routine, and require less conscious thought than others, but without an explicit or implicit plan to guide the required sequence of acts, no letter would get typed.

A Comparison of the Theory of Planned Behavior and the Theory of Reasoned Action

Research in social psychology has extensively referenced and used Fishbein and Ajzens theory of reasoned action to predict and understand motivational influences on behavior Recently Ajzen has proposed an extension of the theory by including perceptions of behavioral control as an additional predictor of intentions and behavior. The present research compared Ajzens theory of planned behavior with the theory of reasoned action for 10 behaviors chosen to represent a range with respect to control over performing the behavior. he results indicate that inclusion of perceived behavioral control enhances the prediction of behavioral intention and behavior Consistent with the theory of planned behavior, the effects of perceived behavioral control on a target behavior are most vivid when the behavior presents some problem with respect to control.

Application of the theory of planned behavior to leisure choice.

The theory of planned behavior (Ajzen, 1985, 1987) is used to predict leisure intentions and behavior. College students completed a questionnaire that measured involvement, moods, attitudes, subjec...

The theory of planned behaviour: reactions and reflections.

The seven articles in this issue, and the accompanying meta-analysis in Health Psychology Review [McEachan, R.R.C., Conner, M., Taylor, N., & Lawton, R.J. (2011). Prospective prediction of health-related behaviors with the theory of planned behavior: A meta-analysis. Health Psychology Review, 5, 97–144], illustrate the wide application of the theory of planned behaviour [Ajzen, I. (1991). The theory of planned behavior. Organizational Behavior and Human Decision Processes, 50, 179–211] in the health domain. In this editorial, Ajzen reflects on some of the issues raised by the different authors. Among the topics addressed are the nature of intentions and the limits of predictive validity; rationality, affect and emotions; past behaviour and habit; the prototype/willingness model; and the role of such background factors as the big five personality traits and social comparison tendency.

Predicting dishonest actions using the theory of planned behavior

Abstract The prediction of dishonest actions was studied in the context of the theory of planned behavior. College students completed a questionnaire that assessed attitudes, subjective norms, perceptions of behavioral control, intentions, and perceptions of moral obligations, as well as self-reports of behavior with respect to cheating on a test, shoplifting, and lying to get out of assignments. A subsample of respondents returned several months later for a second administration of the questionnaire. Multiple regression analyses showed that the theory of planned behavior predicted intentions with a high degree of accuracy, and that it was moderately successful in the prediction of actual behavior. Addition of perceived moral obligations to the prediction equation improved prediction of reported lying behavior, but did not help to account for much variance in cheating and shoplifting. Self-reports of past dishonesty were used to evaluate the sufficiency of the theory of planned behavior.

Residual effects of past on later behavior: Habituation and reasoned action perspectives

The frequency with which a behavior has been performed in the past is found to account for variance in later behavior independent of intentions. This often taken as evidence for habituation of behavior and as complementing the reasoned mode of operation assumed by such models as the theory of planned behavior. In this article, I question the idea that the residual effect of past on later behavior can be attributed to habituation. The habituation perspective cannot account for residual effects in the prediction of low-opportunity behaviors performed in unstable contexts, no accepted independent measure of habit is available, and empirical tests of them habituation hypothesis have so far met with little success. A review of existing evidence suggests that the residual impact of past behavior is attenuated when measures of intention and behavior are compatible and vanishes when intentions are strong and well formed, expectations are implementation have been developed.

Intention, perceived control, and weight loss: An application of the theory of planned behavior.

Success at attempted weight reduction among college women was predicted on the basis of a theory of planned behavior. At the beginning of a 6-week period, participants expressed their attitudes, subjective norms, perceived control, and intentions with respect to losing weight. In addition, the extent to which they had made detailed weight reduction plans was assessed, as were a number of general attitudes and personality factors. In support of the theory, intentions to lose weight were accurately predicted on the basis of attitudes, subjective norms, and perceived control; perceived control and intentions were together moderately successful in predicting the amount of weight that participants actually lost over the 6-week period. Actual weight loss was also found to increase with development of a plan and with ego strength, factors that were assumed to increase control over goal attainment. Other factors, such as health locus of control, perceived competence, and action control, were found to be unrelated to weight reduction.

Attitudes and the Attitude-Behavior Relation: Reasoned and Automatic Processes

The chapter re-examines, in light of recent developments, the reasoned action perspective inherent in the expectancy-value model of attitude and in the theory of planned behavior. According to this perspective, peoples attitudes follow spontaneously and consistently from beliefs accessible in memory and then guide corresponding behavior. The number and types of beliefs that are accessible vary with motivation and ability to process attitude-relevant information and with the context. Based on these considerations, it is shown that the reasoned action perspective is compatible with evidence for automatic processes in the activation of attitudes and behavior, and with the finding that attitudes can vary with the context in which they are expressed. Implications for the attitude-behavior relation and for the role of habit in human behavior are discussed.

Choice of Travel Mode in the Theory of Planned Behavior: The Roles of Past Behavior, Habit, and Reasoned Action

Relying on the theory of planned behavior (Ajzen, 1991), a longitudinal study investigated the effects of an intervention-introduction of a prepaid bus ticket-on increased bus use among college students. In this context, the logic of the proposition that past behavior is the best predictor of later behavior was also examined. The intervention was found to influence attitudes toward bus use, subjective norms, and perceptions of behavioral control and, consistent with the theory, to affect intentions and behavior in the desired direction. Furthermore, the theory afforded accurate prediction of intention and behavior both before and after the intervention. In contrast, a measure of past behavior improved prediction of travel mode prior to the intervention, but lost its predictive utility for behavior following the intervention. In a test of the proposition that the effect of past on later behavior is due to habit formation, an independent measure of habit failed to mediate the effects of past on later behavior. It is concluded that choice of travel mode is largely a reasoned decision; that this decision can be affected by interventions that produce change in attitudes, subjective norms, and perceptions of behavioral control; and that past travel choice contributes to the prediction of later behavior only if circumstances remain relatively stable.