Characteristics of the sibling relationship that predict sibling similarity in adolescent alcohol use: exploring potential shared environmental effects.

Abstract

Using a genetically informative sibling-pair design (N = 613), three studies were conducted to extend knowledge on how siblings influence adolescent alcohol use. Study 1 utilized latent class analysis to determine if patterns of sibling similarity in alcohol use could be detected. The 3-class model was the best fitting for Wave 1, and the 4-class model was the best fitting for Wave 2. Study 2 established the predictive validity of Study 1 by testing characteristics of the sibling relationship (closeness, conflict, communication) at Wave 1 as predictors of sibling similarity in alcohol use patterns at Wave 2. Communication and conflict predicted the 4-class model, but closeness did not. Study 3 utilized Cholesky decomposition in order to decompose the genetic and environmental contributions to the correlation between mom, dad, and sibling involvement in their association with adolescent alcohol use. There were few significant findings, potentially due to power issues. Altogether, this research demonstrates sibling influences on adolescent alcohol use and provides guidelines for future research in my general program of research.