The current study examined whether variability in the OXTR gene moderated associations among (a) the PROSPER project intervention; (b) peer substance use, as reported by nominated peers; and (c) and early adolescent alcohol use measured in the 9th grade. Although our outcome measure was alcohol use, we operationalized peer risk as substance use because it provides a broader measure of youths’ likely exposure to pro-deviance messages that encourage risky behavior (see Sutherland, 1973). Exposure to this context creates risks for youth beginning down an at-risk behavioral pathway themselves, the first steps of which would include alcohol use (see Cleveland & Wiebe, 2008).
