Rodriguez, Lindsey M.Young, Chelsie M.Tomkins, MaryDiBello, Angelo M.Krieger, HeatherNeighbors, Clayton2018-02-262018-02-262016-01Copyright 2016 Addictive Behaviors. This is a post-print version of a published paper that is available at: https://www.sciencedirect.com/science/article/pii/S0306460315300095. Recommended citation: Rodriguez, Lindsey M., Chelsie M. Young, Mary M. Tomkins, Angelo M. DiBello, Heather Krieger, and Clayton Neighbors. "Friends in Low Places: The Impact of Locations and Companions on 21st Birthday Drinking." Addictive Behaviors 52 (2016): 52-57. doi: 10.1016/j.addbeh.2015.08.009. This item has been deposited in accordance with publisher copyright and licensing terms and with the author’s permission.http://hdl.handle.net/10657/2407The 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, Fraternity/Sorority houses, and other. 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.en-US21st birthdayAlcohol useCollege studentsContextEvent-specificArticle