Friends in low places: The impact of locations and companions on 21st birthday drinking

• Examines how specific contextual factors are associated with 21st birthday drinking.
• Celebration locations and companions were used as predictors of drinks and eBAC.
• Drinking at a bar and with Greek members was most strongly associated with drinking.
• Celebrating with romantic partners was associated with lower birthday drinking.

The present research examined how various locations and companions were associated with hazardous drinking during 21st birthday celebrations. The sample included 912 college students (57% female) who completed an online survey to examine 21st birthday drinking. Locations included bars, friends' houses, restaurants, outdoor barbecues, homes, parents' homes, and Fraternity/Sorority houses. Companions included friends, family members, casual acquaintances, roommates, significant others, Fraternity/Sorority members, and none (alone). Participants consumed an average of 7.6 drinks and reached an average eBAC of .15 during their 21st birthday celebrations. Locations accounted for 20%/18% of the variance in number of drinks and eBAC, respectively, whereas companions accounted for 23%/20% of the variance. Drinking with romantic partners was associated with less drinking, whereas drinking with Fraternity/Sorority members was associated with more drinking. Stepwise regressions combining locations and companions suggested that, overall, celebrating in a bar setting and with Fraternity and Sorority members were the strongest variables associated with drinking. With the exception of a bar setting, companions were the most important contextual factors associated with 21st birthday drinking.