Due to practical limitation found in the Theory of Reasoned Action (TRA) such as an inability to cater to non-volitional behaviour towards performing certain actions, the Theory of Planned Behaviour (TPB) was developed in 1985. The main purpose of TPB was to improve the predictive power of TRA to be more applicable to any kinds of behavioural attitude and intention to involve in all type behavioural acts. Findings reflect the needs to carry out some elicitation study on antecedents of attitude, subjective norms, and even perceived behavioural control of the model. This chapter addresses the external influence such as self-efficacy and facilitating condition used as the determinants of perceive behavioural control. As such, attempts were made to pragmatically utilise the theory in research settings by many scholars as well as in this present book.
TopLimitation Of Tra And Development Of Tpb
According to Fishbein and Ajzen (1975), the TRA was grounded in many other vital theories of attitudes such as learning theories, consistency theories, attribution theories and expectancy value theories. The TRA, as explained earlier Chapter one, holds that when a person positively evaluates a behaviour (i.e., attitude) and also thinks that the significant others expect him or her to perform such behaviour (i.e., subjective norm), it will result to his or her higher intention or motivation to do so. Based on this theoretical underpinning amongst the TRA’s component constructs, attitudes, subjective norms, intentions and subsequence behaviour, many empirical studies have been conducted to establish and confirm a set of relationships among them (Sheppard, 1998).
However, the results of some empirical studies have also shown a contrary argument against the relationship between behavioural intention and the actual behaviour claimed in TRA’s underlined philosophy. This contradictory argument marks a new turning point of reference to re-examine the component variables in TRA. It was later discovered that behavioural intention does not always influence actual behaviour, especially behaviour that a person has no complete control over it.
On the basis of this circumstantial limitation, Ajzen (1985) introduced the Theory of Planned Behaviour (TPB) by adding another component variable known as “perceived behavioural control” (PBC). Ajzen (1985, p.36) has clearly pointed out the difference between the TRA and TPB in his own word by saying: “the two theories are identical when the subjective probability of success and the degree of control of internal and external factors reach their maximum values: When subjective probabilities of success and actual control are less than perfect, however, we enter the domain of Planned Behaviour.” Hence, the theory of planned behaviour is an extension of the original theory of reasoned action purposively designed to overcome the deficiency in the predictive capacity of attitudes, subjective norm, and behavioural intention on actual non-volitional behaviour as shown in Figure 1.
Figure 1. Theory of planned behaviour