The Angel and the Devil on your shoulder: Friends mitigate and exacerbate 21st birthday alcohol-related consequences.

Twenty-first birthdays are associated with heavier drinking and more negative consequences than any other high-risk drinking event. Friends are the strongest social influence on young adult drinking; however, previous research on college students' drinking has often only examined individuals' perceptions of "friends" generally. Unfortunately, this may obscure the positive influence of some friends and the negative influence of others. Using data...