Adolescents' relationships to siblings and mothers: A multivariate geneticanalysis

Research has consistently demonstrated that children's behavior toward thei r siblings tends to resemble interactions occurring in the parent-child rel ationship. This study examined the relative contributions of genetic and en vironmental influences to the covariation between sibling relationships and mother-adolescent relationships. Reported and observed family interactions were assessed for 719 same-sex sibling pairs of varying degrees of genetic relatedness. The covariance between mother-adolescent and sibling interact ions was decomposed into genetic, shared, and nonshared environmental compo nents. The overlapping effects of shared environment on the two relationshi p subsystems explained most of the covariance. Smaller but significant gene tic and nonshared environmental effects were also found. The consistency of these findings with family processes, such as modeling, is discussed.