The Influence of Drinking Buddies: A Longitudinal Investigation of Drinking Motivations and Drinking Behaviors in Emerging Adults.

Heavy alcohol consumption and frequent alcohol use are associated with many adverse social and physical consequences. The different motivations underlying why people drink predict different patterns of alcohol consumption. A drinking buddy (i.e. a friend with whom a person drinks alcohol) influences a person's drinking social learning, leading to escalations in drinking over time. Few studies have investigated drinking motives among peers and none have studied whether the drinking motives of a drinking buddy can influence another person's drinking behavior; we sought to fill that gap. Same-sex drinking buddies ( = 174; 66.1% female) were assessed once monthly for four months using self-report questionnaires. Participants were on average 18.66 years-old ( = 1.17). Indistinguishable actor-partner interdependence models using multilevel path analysis were conducted, with each drinking motive predicting drinking frequency and quantity, respectively. There were significant actor effects for social, enhancement, conformity, and coping motives; moreover, the enhancement, social, and coping-anxiety motives of the drinking buddy influenced the individual's drinking frequency across the four months of the study. Conversely, only the enhancement motives of the buddy predicted drinking quantity in the individual when averaged across time. Sex was not a significant moderator of these effects. When targeting risky drinking behavior in a therapeutic context, assessing and addressing a person's reasons for drinking, as well as their drinking buddy's reasons for drinking, may reduce the risk of escalations in either friend's drinking frequency over time.