theory of reasoned action

3 min read 20-03-2025

The Theory of Reasoned Action (TRA), developed by Martin Fishbein and Icek Ajzen in the 1960s, is a prominent model in social psychology that explains how attitudes and subjective norms influence behavioral intentions and, ultimately, behavior. It's a powerful tool for understanding why people make the choices they do, particularly in situations where the behavior is under volitional control—meaning the individual has the power to choose whether or not to perform the behavior. Understanding TRA can be incredibly valuable in fields ranging from marketing and public health to environmental science and beyond.

Key Components of the Theory of Reasoned Action

TRA posits that the most significant predictor of a person's behavior is their intention to perform that behavior. This intention, in turn, is shaped by two key factors:

1. Attitudes Towards the Behavior

This refers to an individual's overall evaluation of performing the specific behavior in question. It's not a general attitude towards the behavior's object; instead, it's a judgment about the behavior itself. For example, someone might have a positive attitude towards recycling (the behavior) even if they have mixed feelings about environmentalism (the object). This attitude is shaped by two things:

Behavioral Beliefs: These are beliefs about the likely outcomes of performing the behavior and the evaluations of those outcomes. If someone believes that recycling will help the environment (positive outcome) and they value a healthy environment (positive evaluation), their attitude towards recycling will likely be positive.
Example: Believing that regular exercise leads to better health (positive outcome) and valuing good health (positive evaluation) creates a positive attitude towards exercise.

2. Subjective Norms

This component reflects the perceived social pressure to perform or not perform the behavior. It considers what an individual believes important others (family, friends, community) think they should do. This is not about what others actually think, but rather what the individual perceives their expectations to be. This is influenced by:

Normative Beliefs: These are beliefs about what significant others think one should do, and the individual's motivation to comply with those expectations.
Example: If someone believes their friends think they should start a new diet (normative belief) and they want to please their friends (motivation to comply), their subjective norm toward dieting will be strong.

The Role of Behavioral Intention

The TRA model suggests that attitudes and subjective norms combine to create a behavioral intention. This intention is the best predictor of whether or not a person will actually perform the behavior. A strong positive intention leads to a higher likelihood of performing the behavior.

Equation: Behavioral Intention = (Attitude towards the behavior) + (Subjective Norm)

Limitations of the Theory of Reasoned Action

While highly influential, TRA does have limitations:

Volitional Control: TRA assumes that behavior is under conscious control. However, many behaviors are influenced by factors beyond conscious choice, such as addiction or lack of resources.
Time: The model doesn't explicitly account for the time elapsed between intention formation and behavior. Intentions can change over time.
Complexity of Behaviors: Some behaviors are complex and involve multiple steps. TRA may be less effective in predicting these complex behaviors.

The Theory of Planned Behavior: An Extension of TRA

Icek Ajzen later expanded upon TRA, developing the Theory of Planned Behavior (TPB). TPB incorporates a third factor: perceived behavioral control. This reflects an individual's belief in their ability to perform the behavior, considering internal and external factors. Perceived behavioral control acknowledges that even with positive attitudes and strong subjective norms, individuals might still fail to perform a behavior if they lack the perceived ability to do so.

Conclusion

The Theory of Reasoned Action provides a valuable framework for understanding the determinants of human behavior. By considering attitudes towards a behavior and subjective norms, it helps explain why people choose to act (or not act) in certain ways. Although it has limitations, especially when dealing with behaviors outside of conscious control, TRA remains a cornerstone of social psychology research and a useful tool for influencing behavior change in various contexts. Understanding this theory can greatly improve the effectiveness of interventions designed to promote positive behaviors and reduce negative ones.