
 The amount a person drinks can be influenced by their perception of drinking by  others.
We studied whether perception of the amount of  drinking by others (same age and sex) is associated with one's own current  drinking, and the factors that are related to this perception. 
A random sample of drinkers (n = 404) from a  census of 20-year-old Swiss men (n = 9686) estimated the percentage of  others who drink more than they do. Using weekly alcohol consumption data of the  census, we computed for each subject the percentage of individuals drinking more  than they do. We compared the ‘perceived’ to the ‘computed’ percentage and  classified the drinkers as overestimating or not drinking by others. We compared  the alcohol consumption of those who overestimated drinking by others to those  who did not, using analyses of variance/covariance. We used logistic regression  models to evaluate the impact of age, education level, occupation, living  environment and family history of alcohol problems on estimations of drinking by  others.
Among the 404 drinkers, the mean (SD) number  of drinks/week was 7.95(9.79); 45.5% overestimated drinking by others, while  35.2% underestimated it and 19.3% made an accurate estimation. The likelihood of  overestimating increased as individual alcohol use increased. Those  overestimating consumed more alcohol than those who did not; the adjusted mean  number of drinks/week (SE) 11.45 (1.12) versus 4.50 (1.08),  P < 0.0001. Except for current drinking, no other variables were  significantly associated with overestimating.
This  study confirms prior findings within selective student populations. It sets the  stage for preventive actions, such as normative feedback based on social norms  theory. 
Request Reprint E-Mail: Nicolas.Bertholet@chuv.ch
 
