Hyde, L., Waller, R., Trentacosta, C., Shaw, D., Neiderhiser, J., Ganiban, J., Reiss, D., & Leve, L. D. (2016). Heritable and non-heritable pathways to early callous unemotional behaviors. American Journal of Psychiatry. Epub ahead of print. doi: 10.1176/appi.ajp.2016.15111381
Abstract: Objective: Callous-unemotional (CU) behaviors in early childhood identify children at high risk for severe trajectories of antisocial behavior and CU traits that culminate in later diagnoses of conduct disorder, antisocial personality disorder, and psychopathy. Studies have demonstrated high heritability of CU traits, but no research has examined specific heritable pathways to earlier CU behaviors. Additionally, studies indicate that positive parenting protects against the development of CU traits, but genetically informed designs have not been used to confirm that these relationships are not the product of gene–environment correlations. Method: Using an adoption cohort of 561 families, biological mothers reported their history of severe antisocial behavior. Observations of adoptive mother positive reinforcement at 18 months were examined as predictors of CU behaviors when children were 27 months old. Results: Biological mother antisocial behavior predicted early CU behaviors despite having no or limited contact with offspring. Adoptive mother positive reinforcement also protected against early CU behaviors in children not genetically related to the parent. High levels of adoptive mother positive reinforcement buffered the effects of heritable risk for CU behaviors posed by biological mother antisocial behavior. Conclusions: The findings elucidate heritable and nonheritable pathways to early CU behaviors. The results provide a specific heritable pathway to CU behaviors and compelling evidence that parenting is an important non-heritable factor in the development of CU behaviors. As positive reinforcement buffered heritable risk for CU behaviors, these findings have important translational implications for the prevention of trajectories to serious antisocial behavior.