Impression management and Self-Deception in traffic behaviour inventories

Abstract

Traffic behaviour questionnaires as self-reports of behaviour are easily biased by Socially Desirable Responding (SDR), especially in investigating ‘normal’ behaviour rather than maximum performance. Despite this fact no instruments are available for measuring traffic related SDR. The present study introduces a new inventory, the Driver Social Desirability Scale (DSDS), for measuring driver impression management (DIM) and Driver Self-Deception (DSD). The DSDS was administered to 203 Finns and 201 Australians holding a driver's license. The two factors explained 35.5% of variance in the Australian sample and 40% in the Finnish sample and showed sufficient internal consistency. Correlations between the Balanced Inventory of Desirable Responding (BIDR) and DSDS showed that general SDR had a moderate effect on traffic-specific SDR. Measures of traffic behaviour correlated more strongly with DSDS than BIDR, whereas the general personality variables had stronger correlations with BIDR than DSDS. These results indicate that DSDS is a more suitable instrument for measuring traffic-related SDR than BIDR. Correlation analyses also indicated that DIM is negatively related to the self-reported number of accidents and punishments, overtaking frequency, speeding, and driving aggression, and positively related to traffic rule compliance. DSD correlated positively with variables measuring sense of control in traffic and in general. There was some connection between DSDS, especially DIM, and driving experience although this was found only in the Finnish data among novice drivers (life-time mileage under 5000 km). In conclusion, correlative analyses based on personality questionnaires and self-reports of traffic behaviour suggested that DIM and DSD scales of DSDS show construct validity and reliability for Australian and Finnish data. Further research is needed to investigate the relation between DSDS and driving behaviour measured in real traffic.