What it shows
Ajzen’s 1991 model in its standard form. Three antecedents shape a person’s intention to act: their attitude toward the behavior, the subjective norm (what they believe people important to them expect) and their perceived behavioral control (how easy or difficult they believe performing the behavior will be). Intention then leads to behavior.
Perceived behavioral control also has a direct path to behavior, drawn dashed as in Ajzen’s figure, and curved two-headed arrows show that the three antecedents are correlated.
How to read it
A plain arrow means one construct leads to another.
A curved two-headed arrow marks a correlation, not a cause.
The dashed arrow is the direct path from perceived control to behavior. Ajzen expects it to hold to the extent that perceived control reflects actual control.
The constructs
- Antecedents: attitude toward the behavior, subjective norm, perceived behavioral control.
- Outcome: intention, then behavior.
- Paths: each antecedent to intention; intention to behavior; perceived behavioral control directly to behavior (dashed).
- Source: Ajzen (1991), Figure 1.
Ways to use it in teaching
Ask students to map a familiar health behavior, such as getting a flu shot, onto the three antecedents.
In a theoretical framework workshop, it shows how a model becomes a set of hypotheses, one per directed path.
The dashed path invites discussion: when would perceived control predict behavior directly?
To see how a theory like this becomes the framework of a study, read our theoretical framework examples.
Sources
Ajzen, I. (1991), "The theory of planned behavior", Organizational Behavior and Human Decision Processes 50(2): 179–211, doi:10.1016/0749-5978(91)90020-T, Figure 1.
