Drivers within natural drinking groups: an exploration of role selection, motivation, and group influence on driver sobriety.

Young people consume alcohol almost exclusively in social contexts, but natural drinking group dynamics are poorly understood. Our research focuses on the drivers' role within natural drinking groups. We conducted breath-test surveys of existing groups of young people at the US/Mexico border crossing before they headed to Tijuana bars, and surveyed them again upon their return. Results indicated an individual's perception of other group member's drinking plans predicts drinking intentions to a greater degree for passengers than drivers. Additionally, drivers who anticipated heavy drinking among other group members returned to the United States with BACs nearly identical to drivers who reported that other group members would not drink at all. This suggests drivers were resistant to normative pressures to drink. Evidence that group-dynamic variables may impact drinking behavior underscores the importance of systematic exploration of natural drinking groups. Furthermore, the knowledge gleaned from studying the dynamics and decision making processes of natural drinking groups could be used to design intervention designed to increase designated driver use and to reduce drinking among designated drivers.