Driving aggression in forensic and non-forensic populations: relationships to self-reported levels of aggression, anger and impulsivity.

A series of four questionnaires - the Buss-Perry Aggression Questionnaire (AQ), the Barratt Impulsivity Scale (BIS-11), the Driving Anger Scale (DAS) and a Driving Violence Inventory (DVI) - were administered to a sample of 473 British drivers consisting of undergraduates (N=185), members of the public (N=106) and offenders (N=182) serving sentences in closed prisons in England (violent=82, non-violent=100). Offenders consistently rated acts of driving aggression as less severe compared with other drivers. Offender attributions of driving violence differed to other drivers in that they were equally likely to perceive obscene gesturing as high or low intensity responses; they also viewed assault as a high intensity response whereas members of the public rated it more severely. Trait levels of anger and aggression were the predictors of driving violence in all groups but previous aggressive behaviour was only a predictor for the offenders. Gender and age were found to be predictors of aggressive driving in non-offenders. Even with the effects of age controlled, offenders (and violent offenders in particular) scored higher on measures of driving anger and aggression. These data suggest that offenders differ in their perceptions of aggressive behaviours experienced in everyday driving and as a consequence are more likely to commit acts that other drivers perceive as violent. As offenders are known to display similar perceptual biases in other domains, identified as precursors to their aggressive behaviour, it seems likely that experience effects (as reflected in the trait measures) underpin differences in driving aggression between offenders and non-offenders.