What is Theory of Reasoned Action / Planned Behavior?
Fishbein's 1975 Theory of Reasoned Action proposed that behavior follows from intention, intention follows from attitude (toward the behavior, not the object) and subjective norms (what important others think), and attitude follows from beliefs about consequences weighted by their evaluations. Ajzen's 1985 Theory of Planned Behavior added perceived behavioral control — does the consumer feel able to do it? The model is one of the most empirically supported in social psychology. Marketers use it to identify which lever to pull: weak belief, hostile norm, or low control.
How Theory of Reasoned Action / Planned Behavior actually works
The framework breaks down into the following moving parts. Knowing what each piece is — and what it is not — is what separates a B-grade answer from an A-grade answer in a written assignment.
- Behavior — the act we want to predict or change
- Intention — the strongest direct predictor of behavior
- Attitude — toward the behavior, computed from beliefs × evaluations
- Subjective norm — perceived social pressure (what others think we should do)
- Perceived behavioral control — perceived ease/difficulty of performing the behavior
A worked example: COVID-19 vaccination campaigns
CDC and state-level vaccination campaigns in 2021 used the TPB explicitly. Belief lever — published efficacy data and side-effect facts. Norm lever — celebrities and trusted local figures publicly vaccinated. Control lever — extended hours, in-pharmacy walk-ins, mobile clinics, employer paid time off. Each lever moved a different population segment. The campaigns that ignored one of the three (e.g., information without access) under-performed those that addressed all three.
Don't lose marks for these
- Treating attitudes about the object instead of the behavior
- Ignoring perceived behavioral control
- Believing intention always converts to behavior — the gap can be 50%
How to use this on the exam
Score-maximizing moves
- Cite Fishbein & Ajzen by name
- Identify which lever (belief, norm, control) is weak
- Pair the model with intention-behavior gap research
When to use Theory of Reasoned Action / Planned Behavior (and when not to)
Use Theory of Reasoned Action / Planned Behavior when your assignment asks you to analyze, structure, or recommend — and when you have at least two data points to populate every cell of the framework. Skip it when the question is asking for a numerical answer or a single recommendation, since Theory of Reasoned Action / Planned Behavior is a structuring tool, not a calculator.