Abstract
This study employed an extended theory of planned behaviour (TPB) to investigate the factors underlying smoking intentions and subsequent smoking behaviour three months later in a population of schoolchildren (N = 741). The TPB provided good predictions of both intentions (R2 = 0.518; attitude, subjective norm and perceived behavioural control significant) and smoking (R2 = 0.299; intentions and PBC significant). However, intention did not fully mediate the subjective norm–behaviour relationship. Moral norm explained additional variance in intentions but not smoking. Perceived family smoking and anticipated regret explained additional variance in both intentions and smoking. Perceived friends' smoking and past behaviour explained additional variance in smoking but not intentions. Findings are discussed in relation to how the TPB can further our understanding of adolescent smoking. Implications for additions to the theory and possible interventions are also considered.