Resumen de Driving under the influence of alcohol: the role of personality and the theory of planned behaviour
Driving under the influence of alcohol is one of the main risks of road accidents. Despite the efforts of governments and institutions to reduce accidents, the number of traffic accidents related to alcohol consumption has remained stable in recent years, accounting for around 30% of fatal accidents.
The reform in 2007 of the Penal Code concerning traffic offences meant an increase in the number of people convicted of reckless driving. Driving under the influence of alcohol accounts for approximately 50% of convictions for crimes against traffic safety. Knowing which are the most relevant psychological characteristics related to this crime would be a step forward in the prevention and intervention in traffic safety, and would help in the design of strategies aiming to prevent this behaviour and the recidivism.
This thesis is structured in two main objectives, which are developed in studies 1 and 2.
Study 1 aims to identify the risk factors for driving under the influence of alcohol, and to determine the psychological characteristics of those who have been convicted for this crime. As in other forms of antisocial behaviour, studies conducted so far reveal the importance of personality and attitudes in the study of drunk driving. Accordingly, in this study we compare personality and attitudes of a group of DUI (driving under the influence of alcohol) offenders and a group of control drivers. A descriptive analysis does not show significant differences between the two groups in any of the personality dimensions, while offenders show more antisocial attitudes. However, results of the regression analysis indicate that driving under the influence of alcohol is related to a high neuroticism, low scores in conscientiousness and strong antisocial attitudes.
The results of this study show a high degree of coincidence between the psychological profile of drunk driving, general antisocial behaviour, and alcohol abuse. These results should be taken into account in the development of prevention programs, identifying those drivers with a higher risk of driving under the influence of alcohol, as well as those profiles with a greater resistance to change. On the other hand, given that attitudes are changeable, antisocial attitudes are a good target to be taken into account in intervention programmes for drivers convicted for a DUI offense.
Study 2 aims to evaluate the usefulness of the Theory of Planned Behaviour (TPB) to predict the intention to drive under the influence of alcohol. The TPB is a widely used model in the study of risky driving. So far, studies on driving under the influence of alcohol support the use of the TPB in this form of risk behaviour, suggesting that intention to drink and drive may be determined by attitudes of the drivers, subjective norms and perceived behavioural control. Therefore, in this study our aim is to test the TPB to predict drunk driving intention in a group of DUI offenders serving a prison sentence, a group of drivers following a diversion programme as an alternative sanction for a DUI offense, and a group of control drivers. On the other hand, we aimed to improve the TPB model, including those personality and attitudinal variables that have been linked to antisocial behaviour and risky driving. Results of this study show that the TPB components are capable of explaining between 20% and 57% of the variance in intention to drive under the influence of alcohol, in line with the results of other studies with similar characteristics. The component with a greater influence on intention is perceived behavioural control. Personality does not represent a significant contribution to the models.
These results highlight the need to include perceived control on the drivers’ ability to drive under the influence of alcohol and the likelihood of being involved in an accident as a result of their impaired driving in interventions focused on preventing drunk driving. They also suggest that intention to drink and drive is not directly influenced by specific personality characteristics, and thus they open new research lines focused on exploring the mechanisms through which personality influences driving under the influence of alcohol.
The final part discusses the implications of these findings in the design and improvement of targeted programmes focused on preventing drunk driving and intervention programmes for DUI offenders.
