The theory of reasoned action (TRA) is a general theory of behavior that was first introduced in 1967 by Martin Fishbein, and was extended by Fishbein and Icek Ajzen (e.g., Fishbein & Ajzen 1975; Ajzen & Fishbein 1980). Developed largely in response to the repeated failure of traditional attitude measures to predict specific behaviors, the theory began with the premise that the simplest and most efficient way to predict a given behavior was to ask a person whether he or she was or was not going to perform that behavior. Thus, according to the theory, performance or non-performance of a given behavior is primarily determined by the strength of a person’s intention to perform (or to not perform) that behavior, where intention is defined as the subjective likelihood that one will perform (or try to perform) the behavior in question.
Although the theory focuses upon behavioral intentions (e.g., to jog 20 minutes every day), it can also predict and explain intentions to engage in categories of behavior (e.g., to exercise) or to reach certain goals (e.g., to lose weight). According to the theory, however, unlike the strong relation between intentions to engage in a given behavior and behavioral performance, there is no necessary relation between intentions to engage in a behavioral category and whether one does (or does not) perform any single behavior in that category or between intentions to reach a specific goal and goal attainment. Thus, although the theory can predict and explain any intention, the TRA recognizes that only intentions to engage in volitionally controlled behaviors will consistently lead to accurate behavioral predictions.
The intention (I) to perform a given behavior (B) is, in turn, viewed as a function of two basic factors: the person’s attitude toward performing the behavior (i.e., one’s overall positive or negative feeling about personally performing the behavior – Ab) and/or the person’s subjective norm concerning his or her performance of the behavior (i.e., the person’s perception that his or her important others think that he or she should [or should not] perform the behavior in question – SN). Algebraically, this can be expressed as: B ~ I = w1Ab + w2SN, where w1 and w2 are weights indicating the relative importance of attitudes and subjective norms as determinants of intention. It is important to recognize that the relative importance of these two psychosocial variables as determinants of intention will depend upon both the behavior and the population being considered. Thus, for example, one behavior may be primarily determined by attitudinal considerations while another may be primarily influenced by perceived norms. Similarly, a behavior that is attitudinally driven in one population or culture may be normatively driven in another. While some behaviors may be entirely under attitudinal control (i.e., w2 may be zero) others may be entirely under normative control (i.e., w1 may be zero).
The theory also considers the determinants of attitudes and subjective norms. On the basis of Fishbein’s earlier (1963) expectancy value model, attitudes are viewed as a function of behavioral beliefs and their evaluative aspects. Algebraically: Ab = f(Σbiei), where Ab = the attitude toward performing the behavior, bi = belief that performing the behavior will lead to outcome “i” and ei = the evaluation of outcome “i.” Somewhat similarly, subjective norms are viewed as a function of normative beliefs and motivations to comply. Algebraically: SN = f(ΣNbiMci), where SN = the subjective norm, Nbi = the normative belief that referent “i” thinks one should (or should not) perform the behavior and Mci = the motivation to comply, in general, with referent “i”.
Generally speaking, the more one believes that performing a given behavior will lead to positive outcomes and/or will prevent negative outcomes, the more favorable will be one’s attitude toward performing that behavior. Similarly, the more one believes that specific referents (i.e., individuals or groups) think that one should (or should not) perform the behavior, and the more one is motivated to comply with those referents, the stronger will be the perceived pressure (i.e., the subjective norm) to perform (or to not perform) that behavior.
It is at the level of behavioral and normative beliefs that the substantive uniqueness of each behavior comes into play. Even if two behaviors appear quite similar, the outcomes (or consequences) of, for example, buying a Ford may be very different from those associated with buying a Toyota. Similarly, a specific referent’s support or opposition to my always using a condom for vaginal sex with my main partner may be very different from his or her support or opposition to my always using a condom for vaginal sex with an occasional partner. According to the theory, these specific behavioral and normative beliefs about the behavior in question must be identified in order to fully understand the determinants of that behavior. Although an investigator can sit in her or his office and develop measures of attitudes and subjective norms, she or he cannot tell you what a given population (or a given person) believes about performing a given behavior. Thus one must go to members of that population to identify salient behavioral and normative beliefs. To put this somewhat differently, according to the theory, one must understand the behavior from the perspective of the population one is considering.
Finally, the TRA also considers the role played by more traditional demographic, economic, personality, attitudinal, and other individual difference variables, such as perceived risk or sensation seeking. According to the model, these types of variables primarily play an indirect role in influencing behavior. That is, these “distal” or “background” factors may or may not influence the behavioral or normative beliefs underlying attitudes and norms. Thus, for example, while men and women may hold different beliefs about performing some behaviors, they may hold very similar beliefs with respect to others. Similarly, rich and poor, old and young, those from developing and developed countries, those with favorable and unfavorable attitudes toward religion, and those who have or who have not used drugs may hold different attitudinal and normative beliefs with respect to one behavior but may hold similar beliefs with respect to another. Thus, according to the theory, there is no necessary relation between these “distal” or “background” variables and any given behavior. Nevertheless, distal variables such as cultural and personality differences and differences in a wide range of values may influence underlying beliefs, and when they do so, they are likely to also be associated with the behavior in question.
Application of The Theory of Reasoned Action
In order to apply the TRA, one must first identify the behavior (or behaviors) that one wishes to understand, predict, change, or reinforce. Unfortunately, this is not as simple or straightforward as is often assumed. As indicated above, it is important to distinguish between behaviors, behavioral categories, and goals. Moreover, from the perspective of the TRA, the definition of a behavior involves several elements: an action (joining, using, buying, selling), the target (the navy, condoms, a Ford), and the context (after graduating high school, for vaginal sex with an occasional partner).
Clearly, a change in any one of the elements changes the behavior under consideration. Thus, for example, as indicated above, joining the navy is a different behavior than is joining the Army (a change in target). Similarly, using a condom for vaginal sex with an occasional partner is a different behavior than is using a condom for vaginal sex with one’s spouse (a change in context). Moreover, in predicting and assessing behavior, it is also important to include an additional element – time. For example, an assessment of whether one bought a car in the past three months is different from an assessment of whether one bought a car in the past two years. Consistent with this, the intention to buy a car in the next three months is very different from the intention to buy a car in the next two years.
The second step in applying the TRA is to identify the specific population to be considered. As indicated above, for any given behavior, both the relative importance of attitudes and norms as determinants of intention (and/or behavior) and the substantive of the behavioral and normative beliefs underlying these determinants may also vary as a function of the population under consideration. Thus, it is imperative to define the population (or populations) to be considered.
Once one or more behaviors and target populations have been identified, the TRA can be used to understand why some members of a target population are performing the behavior and others are not. That is, by obtaining measures of each of the central variables in the theory (i.e., beliefs, attitudes, norms, intentions, and behavior), one can determine whether a given behavior (e.g., getting a mammogram) is not being performed because people have not formed intentions to get a mammogram or because they are unable to act on their intentions. Similarly, one can determine, for the population under consideration, whether intention is influenced primarily by attitudes or norms. Finally, one can identify the specific behavioral or normative beliefs that discriminate between those who do or do not (intend to) perform the behavior.
For accurate prediction and full understanding of a given behavior, measures of beliefs, attitudes, norms, and intention must all correspond exactly to the behavior to be predicted. That is, each of the measures should contain the same four elements as the behavior. This is known as the principle of correspondence or compatibility, and is central to the TRA. This does not mean, however, that one must always measure behaviors and intentions at a specific level of all four behavioral elements. If one is interested in predicting whether one will or will not get a mammogram in the next six months, beliefs, attitudes, norms, and intentions must all be assessed with respect to “my getting a mammogram in the next six months.” However, if one is interested in predicting whether one will or will not get a mammogram at Women’s Hospital in the next six months, beliefs, attitudes, norms, and intentions must all be assessed with respect to “my getting a mammogram at Women’s Hospital the next six months.”
In 1991, Ajzen introduced the theory of planned behavior, which extended the TRA by adding the concept of perceived behavioral control as a predictor of both intention and behavior. And in 2000, Fishbein introduced the integrative model, which extended the theory of planned behavior by expanding the normative component to include descriptive as well as injunctive norms, and by explicitly acknowledging the role of skills and abilities and facilitating factors as moderators of the intention–behavior relationship. The reasoned action approach has been used successfully to predict and/or explain a wide variety of behaviors, including such things as wearing safety helmets, smoking marijuana, voting, eating at fast food restaurants, smoking cigarettes, drinking alcohol, entering an alcohol treatment program, using birth control pills, breast feeding, donating blood, wearing seat belts, condom use, church attendance, and engaging in premarital sexual behavior (see, e.g., Ajzen et al. 2007; Van den Putte 1993).
- Ajzen, I. (1991). The theory of planned behavior. Organizational Behavior and Human Decision Processes, 50(2), 179–211.
- Ajzen, I., & Fishbein, M. (1980). Understanding attitudes and predicting social behavior. Englewood Cliffs, NJ: Prentice Hall.
- Ajzen, I., Albarracin, D., & Hornik, R. (eds.) (2007). Prediction and change of health behavior: Applying the reasoned action approach. Mawah, NJ: Lawrence Erlbaum.
- Fishbein, M. (1963). An investigation of the relationships between beliefs about an object and the attitude toward that object. Human Relations, 16, 233–240.
- Fishbein, M. (1967). Attitude and the prediction of behavior. In M. Fishbein (ed.), Readings in attitude theory and measurement. New York: John Wiley, pp. 477–492.
- Fishbein, M. (2000). The role of theory in HIV prevention. AIDS Care, 12(3), 273–278.
- Fishbein, M., & Ajzen, I. (1975). Belief, attitude, intention and behavior: An introduction to theory and research. Boston: Addison-Wesley.
- Van den Putte, B. (1993). On the theory of reasoned action. Unpublished doctoral dissertation. University of Amsterdam.
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