A new study shows that alcohol consumption of individuals appears to increase with the number of friends in their drinking group.

Most alcohol use among young people occurs in a social context, and peer substance use has long been established as an important predictor of alcohol and other substance use among youngsters. Past research suggests that the mere presence of others seems to have an effect on drinking behaviour, but most of those studies relied on data gathered from experiments performed in artificial laboratory settings or from surveys conducted after drinking sessions have ended, which are notoriously inaccurate.

The new study used Internet-based questionnaires that study participants completed on their own smartphones to survey almost 200 young adult drinkers in Switzerland every hour while they were drinking in real-life situations, asking them to report the number of friends present and number of drinks they had consumed.

Results showed that as the number of friends present increased, so did the number of drinks an individual consumed per hour. This suggests that messages aimed at reducing risk among young drinkers should aim to combat this tendency. The arrival of more drinking buddies at the college bar on a Friday night may be cause for delight, but not necessarily a call for another round of drinks.

The impact of drinking group size on alcohol use is stronger for men than women.

Published in Addiction