The genetic epidemiology of parental discipline

Background. Previous studies of parental discipline have identified little influence of heritability on parental control, and some influence of gene-environment correlations, shared environment and child temperament. Method. Using interview data from 2003 female twins from a population-based twin registry and 1472 of their parents, we examined reports of parental discipline from four perspectives: (1) father and mother reporting separately on the type of discipline they provided for their offspring; (2) each twin reporting on the type of discipline they received from their parents; (3) each parent reporting on the discipline provided by their spouse; and, (4) each twin reporting on the discipline they provided for their own offspring. Using factor analysis and univariate structural equation modelling, we examined the structure of parental discipline, and the genetic and environmental influences thereon. Results. The seven discipline items yielded two factors, physical discipline and limit setting, which were moderately positively correlated. Parents perceived discipline as largely a common environmental experience for the twins, whereas the twins indicated that discipline was influenced by unique environmental factors and the genotype of the child. Twins as parents indicated no influence of shared environment on discipline, with the majority of influence accounted for by non-shared environment and parental genotype. Conclusions. Parents recall providing similar discipline to their children, whereas children emphasize the differences in parental discipline. Sources of individual variation in parental discipline vary according to which family member report is examined. In total, parental discipline is partially influenced by the genotype of both the parent and child, and by environmental factors shared by the twins and unique to the individual.