Development and validation of the traffic displaced aggression questionnaire.

• Displaced aggression on the road has hardly been studied to date. • A self-report to assess it is developed and validated. • It has two reliable factors based on where the anger arised. • Both factors showed good psychometric properties. • Slight but significant effects were obtained by age and gender. Displaced aggression is defined as the aggression conducted against someone or something that is not considered to be the trigger of the emotional state of the aggressor. Whereas it has been deeply studied in a general context, to date, very few studies have analysed it in the specific context of driving. Considering the inexistence of instruments to assess it, the aim of the current research was to develop and validate a self-report in order to assess displaced aggression in the driving context. A sample of 467 participants (66.8% female, M age = 34.74) filled in a set of questionnaires including the 29 items that were designed to assess traffic displaced aggression, as well as other instruments measuring different ways of expressing both general and driving aggression. The results of both Parallel Analysis (PA, sub-sample 1) and Confirmatory Factor Analysis (CFA, sub-sample 2) showed a good fit of the two-factor model, retaining 20 out of the initial 29 items. The first factor was labelled as Displaced aggression due to the anger generated outside the vehicle (6 items, α = 0.83), whereas the second factor was labelled as Displaced aggression due to the anger generated inside the vehicle (14 items, α = 0.91). Both factors, as well as the total score, showed good results regarding convergent and divergent validity. Practical implications of the results, future research lines and limitations of the current study are discussed. [ABSTRACT FROM AUTHOR]