Parenting and child behavioral adjustment in early childhood: A quantitative genetic approach to studying family processes

The aim of this study was to examine environmental and gene-environment pro cesses linking parenting (i.e., affect, control, responsiveness) and presch ool children's behavioral adjustment difficulties (e.g., noncompliance, con duct problems) by using bivariate genetic analyses of parents' and observer s' ratings. The sample included 120 identical and same-sex fraternal twin p airs (M age = 43 months). Data sources included in-home observations, inter views, and parents' reports. Observers' ratings of children's difficult beh aviors included shared and nonshared environmental variance. In contrast, p arents' ratings of children's conduct problems showed genetic and nonshared environmental variance. Observer-rated maternal behavior included shared a nd nonshared environmental variance, although maternal responsiveness also included child genetic variance. Parent self-reported negative and positive affect included shared and nonshared environment as well as child genetic variance. There was no evidence for gene-environment interaction or dominan ce. Higher levels of difficult behavior and conduct problems covaried with higher levels of maternal negative affect and control and lower levels of m aternal positive affect and control. Shared environmental mediation of thes e correlations was found for observations, whereas genetic and nonshared en vironmental mediation was found for parents' ratings. in general, estimates of shared environmental variance and mediation were greatest for observati onal data, and estimates of child genetic variance and mediation were great est for parent-rated data. The implications of this pattern of findings for genetic research on family processes are discussed.