Introduction

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Ajzen and Fishbein's Theory of Reasoned Action was developed in 1967 and is divided up into three main areas. The first area is intention. The main premise of this theory is that a person's intention is the main predictor and influencer of behavior. If a person intends to do something then they will more than likely do it. If they do not intend to do a behavior then they will more than likely not do it.

The Theory of Reasoned Action suggests that there are two main influencers of intention. They are the Attitude toward the behavior and Subjective Norms.

Further Description of Theory

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TRA posits that individual behavior is driven by behavioral intentions where behavioural intentions are a function of an individual's attitude toward the behaviour and subjective norms surrounding the performance of the behavior.

Attitude toward the behavior is defined as the individual's positive or negative feelings about performing a behaviour. It is determined through an assessment of one's beliefs regarding the consequences arising from a behavior and an evaluation of the desirability of these consequences. Formally, overall attitude can be assessed as the sum of the individual consequence x desirability assessments for all expected consequences of the behavior.

Subjective norm is defined as an individual's perception of whether people important to the individual think the behavior should be performed. The contribution of the opinion of any given referent is weighted by the motivation that an individual has to comply with the wishes of that referent. Hence, overall subjective norm can be expressed as the sum of the individual perception x motivation assessments for all relevant referents.

Algebraically TRA can be represented as B ≈ BI = w1AB + w2SN where B is behavior, BI is behavioral intention, AB is attitude toward behavior, SN is subjective norm, and w1 and w2 are weights representing the importance of each term.

The model has some limitations including a significant risk of confounding between attitudes and norms since attitudes can often be reframed as norms and vice versa. A second limitation is the assumption that when someone forms an intention to act, they will be free to act without limitation. In practice, constraints such as limited ability, time, environmental or organisational limits, and unconscious habits will limit the freedom to act. The Theory of planned behavior (TPB) attempts to resolve this limitation.

How the Theory is Applied

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Ajzen and Fishbein's model has been adapted for use in many fields and much of their research backs up there assumptions which is why it is so widely used in academia and business today.