Psychophysiological reactivity of aggressive drivers: an exploratory study

In the United States, motor vehicle accidents are the leading cause of accidental death and injury. Aggressive driving, which has been identified as a major risk factor for motor vehicle accidents by transportation authorities, is thus an important topic of study. This study compared the physiological reactivity of self-referred aggressive and nonaggressive drivers. Heart rate, blood pressure, facial muscle activity, and skin resistance were monitored as participants listened to idiosyncratic vignettes of driving and fear-provoking scenarios, as well as during a standard stressor task (mental arithmetic). The results were that aggressive drivers exhibited significant increases in muscle tension and blood pressure during the driving vignettes, relative to controls. They also responded to the fear vignette and mental arithmetic in a qualitatively different fashion from that of controls. The aggressive drivers responded to these stimuli with less overall heart rate and electrodermal reactivity, but increased blood pressure and muscle tension. In contrast, the controls responded to the fear vignette and mental arithmetic primarily with increased heart rates and decreased skin resistance. The findings suggest that both physiological hyperarousal as well as differential responses to stressful stimuli may contribute to aggressive driving. Implications for interventions with this population are discussed.