Research has long demonstrated that siblings are similar in their alcohol use, however much of this work relies on cross-sectional samples or samples of adolescents alone and/or exclusive focus on older siblings’ impact on younger siblings. Using a three time-point design from early adolescence to early adulthood (M ages = 14.9, 18.3, and 22.4 years, respectively; 55% female; 54% European ancestry, 38% Asian ancestry), we evaluated the prospective older and younger sibling influences on alcohol use across time (N = 613 sibling pairs; 35% sisters, 26% brothers, 39% mixed-gender; average age difference = 2.34 years; 34% full-biological siblings, 46% genetically-unrelated adopted siblings, 20% pairs where one child was the biological offspring of parents and the other was adopted). The results from both the traditional and random-intercept cross-lagged panel analyses showed that older siblings’ alcohol use predicted younger siblings’ alcohol use across each developmental transition and across a variety of sibling contexts (e.g., gender composition, age difference, genetic relatedness). On the other hand, younger siblings’ alcohol use only predicted older siblings’ alcohol use when siblings were close in age (1.5 years or less) and under conditions of high sibling companionship. These results add to a body of literature illustrating how both older and younger siblings are important socializing agents of adolescent and early adult alcohol use. Assessing or co-treating siblings for alcohol problems may be an important add-on to existing adolescent and early adult alcohol prevention and intervention programs.
Bibliographical noteFunding Information:
Funding This research was supported by Grants AA11886 from the National Institute on Alcohol Abuse and Alcoholism and MH66140 from the National Institute of Mental Health. The first author was also supported by the USDA National Institute of Food and Agriculture, Hatch project 1006129. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.
We would like to thank the participating families from the Sibling Interaction and Behavior Study and the recruitment, interviewing, and data management staff at the Minnesota Center for Twin and Family Research. D.R.S. conceived the idea for this manuscript and completed the initial draft of the intro, method, and discussion sections as well as the bulk of the revisions. R.J.G. and L.R. assisted with data analysis and prepared initial drafts of the results section (L.R. descriptive statistics, R.J.G. inferential statistics). D.R.S., R.J.G., and L.R. reviewed and edited multiple drafts of the manuscript. D.R.S. handled all revisions prior to other co-author approval. M.M. and W.G.I. are the Principal and Co-Investigator of the SIBS (data source) thus participated in the design of the study and provided edits, feedback, and suggestions on the manuscript. This research was supported by Grants AA11886 from the National Institute on Alcohol Abuse and Alcoholism and MH66140 from the National Institute of Mental Health. The first author was also supported by the USDA National Institute of Food and Agriculture, Hatch project 1006129. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies. The authors declare that they have no competing interests.
- Alcohol use
- Deviancy training
- Young adulthood