A City Guide To Tangail for These studies confirmed the importance of attitudes and subjective norms in explaining intention, and of intention in predicting subsequent behaviour. This meta-analysis reported that the mean correlation of attitudes and social norms with intentions was approximately , and the correlation between intention and behaviour was between and This therefore improves significantly on the prediction afforded by the HBM components; however, the model still has limitations. Note also that research evidence supporting a link between intention and subsequent behaviour has been limited by an over-reliance on cross-sectional studies. Limitations of the TRA The TRA was initially developed for application to volitional behaviour that under the person’s control and as such does not examine a person’s belief in their ability to perform the behaviour in question. However, much behaviour is not completely volitional for example, addictive behaviours such as smoking, or the negotiation of condom use during sexual encounters. This was addressed in the developed model, the TPB. n The theory of planned behaviour In order to improve the model’s ability to address non-volitional behaviour, the TRA was extended to include the concept of perceived behavioural control, becoming known as the theory of planned behaviour Ajzen , ; see Figure Perceived behavioural control PBC is defined as a person’s belief that they have control over their own behaviour in certain situations, even when facing particular barriers e. A City Guide To Tangail 2016.