Individual interventions to prevent drunk driving: types, efficacy, and a theoretical perspective.

College students (n = 100) who had tried to stop someone from driving drunk, or who someone else had tried to stop, provided information about their interaction, including what was said and whether the intervention worked. Results suggest that the manner in which people intervene can affect the likelihood that the impaired person will not drive, with forceful statements, clear demands, and concrete action being more effective than requests, pleas, or suggestions. The hypothesis that intervention represents a threat to the person's image received limited support, possibly for methodological reasons. The concept of threat to competence is discussed, as are implications of the results for prevention and education activities.