In behavioral medicine, professionals base their interventions on a few models that attempt to explain people’s health-related behavior: the health belief model, reasoned and planned behavior theory, learning theories/classical conditioning, and social cognitive theory. These models are termed continuum theories, for they aim to recognize variables that influence people’s behavior, and using the sum of variables, how likely the person will engage in a particular behavior (Weinstein, Rothman, & Sutton, 1998). They are often criticized on their narrow focus on outcome behavior of interest (e.g. smoking cession) and its non-inclusion of race, gender, and socioeconomic status — all features known to have a somewhat strong influence on health behavior. Nonetheless, the model dynamics are useful to describe particular types of behavior.

Health Belief Model

As the one of the earliest frameworks for understanding human behavior, the health belief model declares that individuals will take health related actions based on six types of factors and associated beliefs:

Perceived Susceptibility: the condition may hurt the individual on any aspect of the biopsychosocial model.

Perceived Severity: the condition is severe enough to have a negative consequence.

Perceived Benefits: the advised actions may stop, lower, or lessen the affect, risk, and consequences of the condition, respectively.

Perceived Barriers/Costs: the corrective/preventive benefits outweigh the psychological and physical harms of abiding to the advised behavior.

Cues to Action: there is an internal or external cue, or both, that trigger the individual to finally act.

This model is better for predicting simple, one-time or limited behaviors (e.g. immunizations) than habitual behaviors.

Reasoned Action & Planned Behavior Theory

This theory recognizes that individuals act rationally and emphasizes the power of individual’s intention to induce behavior governed by three principles:

Attitudes: the individual’s positive or negative feelings about engaging in a given behavior.

Subjective Norms: standards or influences established by the individual’s larger context, for instance, familial beliefs, media conceptions, and societal models.

Perceived Behavioral Control: the degree to which the individual could perform a behavior.

The theory is limited to discrete sample populations and does not incorporate profiles of previous behaviors nor does it address when positive intentions are not enough to enact behaviors (e.g. cues of action).

Learning Theories/Classical Conditioning

Based on the principles of classical conditioning, learning theories takes into account the previous responses individual’s had “learned” due to similar stimuli. Desired behaviors stem from positive experiences, associations, and thus responses to stimuli. Consequently, this theory allows reinforcing behaviors by way of rewards, but they are dependent on continual rewards – the precise problem in drug addiction and abuse.

Social Cognitive Theory

Through a variety of mediums, the social cognitive theory states that individuals observations affect behavior by two modes of modeling:

Direct Modeling: Observing others in their social network engaging in a particular behavior (i.e. vicarious learning)

Symbolic Modeling: Individuals more likely model behaviors by others they identify with as portrayed in the media.

Importantly, the modeled learning governed behavioral execution by the individual’s belief in their ability to engage in the behavior (self-efficacy) and consequences of carrying it out (expectancies).

This theory has proven successful in a variety of health-related behaviors, including, smoking cessation, condom use, and regular exercise.

Specialists have also mapped the traditional transtheoretical model or the newer precaution adoption process model in order to stop or reduce unhealthy traits and develop or enhance healthy actions (see table below). These two models categorize the changes individuals go through in the process of behavioral alteration in discrete stages.

Transtheoretical Model

Change is process divided into five stages:

Precontemplation - Unaware or ignorant of the problem, or underestimate its consequences or personal applicability.

Contemplation - Considering making a change to their behavior, often due to an increased awareness or realization of the issue.

Preparation - Commits to change, and organized steps to enact change within a specific time period.

Action - The behaviors are publicly modified to provoke change.

Maintenance - Sustains change, usually over six months

[At the action and maintenance stages, the individual is most prone to relapse.]

The model posits that change occurs in a spiral linear pattern, that is, the individual may move forward or backward until the change is complete.

Precaution Adoption Process Model

Change is process divided into seven stages:

Stage 1 – Now aware of the problem.

Stage 2 – Limited awareness, however, not appreciative of personal risk.

Stage 3 – Acknowledges personal susceptibility of hazard, but fails to make a decision on acting.

Stage 4 – Decides the action is unwarranted.

Stage 5 – Decides the action is warranted.

Stage 6 – The behaviors are publicly modified to provoke change.

Stage 7 – Sustains change, usually over six months

This new model of change further differentiates personal risk profiles and whether the person decides to act.

Further studies must evaluate the effectiveness of each model on predicting health behavioral change; however, it is likely that they are each best for specific types of individuals or behaviors.