Th e theory of planned behavior is another model that has received a consider- able degree of recognition in behavioral and cognitive–behavioral circles. One reason for this was the long-standing realization that people’s attitudes are very poor predictors of their actual behavior. Saying and doing are not the same things. Ajzen and Fishbein (1973) formulated their theory of reasoned action in an attempt to explain this discrepancy. A better predictor of someone’s behavior is their intention to perform it, but the road to hell is still paved with good intentions. Intention in their model is a cognitive representation of the action preceding the actual behavior. Intention is a function of attitude toward the behavior and subjective norms. Ajzen (1991) later added the construct of perceived behavioral control and the expanded model was called the theory of planned behavior.
Attitudes about a behavior are the person’s positive or negative feelings about performing it. Th ese are infl uenced by behavioral beliefs concerning the desir- ability of the perceived consequences of performing the behavior. Subjective norms are the person’s judgment regarding how the behavior will be perceived by people important to that individual. Behind this judgment are normative beliefs. Because attitudes and perceived norms can be easily confounded, there are ambiguities in the model. But of greater concern is that the model assumes individuals have the freedom to act once the intention is formed. By adding per- ception of the ease with which the behavior can be performed (beliefs about behavioral control), however, the theory of planned behavior does accommodate constraints on action, such as limited time, resources, ability, and environmen- tal barriers. If perceived control is accurate then that variable has a direct eff ect on behavior rather than going through the mediating variable of intention.
Th e implication of the theory for therapeutic change is that the individual’s underlying beliefs (attitudes, subjective norms, and control beliefs) all need to be changed. When proposing a strategy or other action for a client to engage in, you could estimate the behavioral beliefs by asking the person to suggest the benefi ts or value of the behavior—and you would be excused for thinking this sounds a lot like parts of motivational interviewing. Similar questioning (which can be accomplished by the use of various questionnaires) should reveal the client’s normative beliefs (“I couldn’t go to the gym fi ve times a week because my friends would think it rather odd”) and control beliefs (“I can’t aff ord gym membership, and I don’t have time to go during the day”). If the control beliefs are more around personal ability (“I’m not really good at lifting weights”) they
are essentially the same as those that Bandura called “self-effi cacy beliefs,” to be discussed again later.
Quite apart from other insights provided by the model, it does explain why to some extent simply providing information to clients can eff ectively change their behavior for their benefi t, especially toward a healthier lifestyle (Hardeman et al., 2002). Th e beliefs that individuals express are not judged to be dysfunctional core beliefs, as in cognitive theory (Chapter 8); they may be perfectly rational (the client cannot actually aff ord the gym membership), and they may be unique to the person (“my wife would be really pleased if I started going to the gym”). So to get from beliefs to intentions, and from intentions to performing new actions, the therapist’s task is to provide new and alterna- tive information, or encourage the client to seek it, which will allow beliefs to be tested, challenged, or experientially disconfi rmed (this being a bit like the behavioral experiment we will encounter in cognitive therapy).
A widely accepted model in health psychology that is basically quite similar proposes that whether an individual adopts a health-related behavior depends on perceived threat, perceived barriers (to change), and specifi c triggers that cue a new behavior. Th is Health Belief Model (see Conner & Norman, 1995), as it is called, suggests that perceived threat is a function of someone’s sense of suscep- tibility to, and someone’s understanding the consequences of, a particular dis- ease. Perception of barriers is based on a balance of the costs and benefi ts of the behavior change. As defi ned by Glasgow (e.g., Glasgow, Toobert, & Gillette, 2001), a perceived barrier is a client’s estimate of the challenge provided by social, per- sonal, environmental, and economic obstacles to a behavior at the desired level of achievement. In their example, applying the model to self-management in diabetes, both the required behavior (correctly administering insulin) and a typical barrier (fear of hypoglycemia) are syndrome specifi c. Change principles are universal, but their translation into many domains of practice often requires specialized, problem-specifi c knowledge.
In the health belief model appraisals of potential risks and gains precede the determination to change unhealthy lifestyles. In the theory of planned behavior motivating change requires targeting three types of belief. Neither has much to say about how appraisals and beliefs are to be changed, except that the beliefs of interest are not seen as deep-seated, largely unconscious, or irrational. Th us, it is assumed, such beliefs are fairly easily altered by ratio- nal discourse, new information, and alternative perspectives on the client’s situation. If it were that simple, however, why don’t people just routinely take action and do more of the things they know are good for them: eat healthier food, exercise more, recycle, put up the storm windows before the winter snow, study hard to get good grades that will facilitate college entrance, or send that check to the Salvation Army’s earthquake appeal? Behavior theory has a sim- pler answer: the less desirable but more convenient alternatives are often pow- erfully reinforced.