EXTENDING THE THEORY OF PLANNED BEHAVIOR - THE ROLE OF PERSONAL NORM

This study assesses the sufficiency of Ajzen's (1985) theory of planne d behaviour in predicting intentions to commit each of three driving v iolations involving poor lane discipline: cutting across traffic to le ave a motorway; weaving in and out of two lanes of slow-moving traffic ; and overtaking on the inside. Behavioural intention was predicted re asonably well by the three main constructs of the theory of planned be haviour. However, the addition of measures of anticipated regret and m oral norm substantially improved prediction in each case, suggesting t hat personal normative influence is an important factor in shaping int entions to perform behaviours that are antisocial or socially controve rsial. The development of a belief-based measure of perceived behaviou ral control is also considered.