BackgroundWe examined how mothers' protective parenting and alcohol use influenced changes in offspring's heavy drinking among a sample of African American youth. The conceptual model also tested indirect effects of mothers' behaviors, through changes in the youths' social images (i.e., prototypes) of heavy drinkers, derived from the prototype willingness (PW) model.MethodsParticipants were 686 emerging adults (55% female) from the Family and Community Health Study (FACHS), an ongoing prospective study of African American families. Three waves of FACHS data were used as follows: T3 during 10th grade (M age = 16.3 years), T4 shortly after high school (M age = 19.4 years), and T5 3 years later (M age = 22.1 years). Mothers' self‐reports of protective parenting and alcohol use were assessed at T4. Two separate path models tested the study hypotheses. The first model specified direct and indirect effects of mothers' protective parenting and alcohol use. The second model added interaction terms between the protective parenting behaviors and mothers' alcohol use. The analyses were first conducted using the full sample and then repeated separately for female and male participants.ResultsMaternal alcohol use had a positive and direct effect on offspring's alcohol use. Mothers' endorsement of alcohol‐related rules inhibited normative increases in the favorability of the offspring's social image of heavy drinkers (prototype) while her warmth was positively related to these increases. Maternal alcohol use amplified the positive association between mothers' warmth and the daughters' increased drinking. For sons, maternal alcohol use increased the positive association between alcohol‐related rules and increased prototype favorability.ConclusionsResults indicated clear gender differences in how mothers' behaviors influence her offspring's alcohol use during the transition to emerging adulthood. Interventions that target culturally specific risk and protective factors within the family environment are needed to reduce health disparities among this vulnerable population of youth.