Differences in Parenting Behavior are Systematic Sources of the Non-shared Environment for Internalizing and Externalizing Problem Behavior.

Although there is evidence for non-shared environmental links between parenting and problem behavior, so far, age-, informant-, and parent-specific patterns for both internalizing and externalizing problem behaviors have not been examined within one study yet. Using the twin differences design, the present study aimed to test how maternal and paternal parenting systematically act as a source of non-shared environment for problem behavior across different age groups and informants. We examined 1327 monozygotic twin pairs and their parents drawn from three birth cohorts of the German TwinLife study. Our results revealed that particularly child-reported less positive and more negative parenting by both parents contribute significantly to the unique environmental variance of problem behavior, although we did not find a clear pattern across age groups. Our study underlines the necessity of controlling for genetic confounding to uncover the truly environmentally mediated (and thus environmentally influenceable) pathways between parenting and problem behavior. A practical implication could be that it may be useful to primarily consider the child's perspective and focus on maternal as well as paternal parenting in interventions that address parenting to reduce problem behavior.