Heritable, Prenatal, and Environmental Pathways of Parental Stress: Differential Influences on Children’s Effortful Control and Cortisol Regulation

Abstract

Parental stress can have lasting consequences on children’s stress sensitivity and self-regulation capacities. However, it remains unclear the extent to which these effects reflect birth parent influences (genetic and/or prenatal), environmental rearing experiences, and/or interactions between them. Parent–offspring adoption designs offer a powerful framework for disentangling these mechanisms by separating birth parent influences from post-natal environmental pathways when the adoptions occur around the time of birth. Although stress experiences of birth parents and adoptive parents have each been associated with child developmental outcomes, the relationship between them remains unexplored. The present study leverages a parent-offspring adoption approach to examine the associations of birth mother life stress with adolescents’ effortful control (EC) via child diurnal cortisol slopes (a marker of hypothalamic–pituitary–adrenal [HPA] axis functioning) and whether adoptive mothers’ or fathers’ experience of stressful life events moderate this relationship. Participants were drawn from families participating in the longitudinal Early Growth and Development Study. The analytic sample included 561 adopted children, and their birth and adoptive parents. Structural equation modeling revealed that birth mother life stress was linked to poorer adoptee EC in adolescence; neither adoptive mothers’ nor fathers’ experiences of stressful life events predicted adoptee EC. Among adoptive parents, only fathers’ experiences of stressful life events predicted child diurnal cortisol slopes, such that greater adoptive fathers’ stress was linked to flatter adoptee wake-to-bedtime cortisol slopes. However, the hypothesized mediation and moderation effects were not supported. These findings show how the birth parent influences (genetic and/or prenatal) and rearing dimensions of parental stress have differential impacts on the child’s neurobiological functioning and development, where birth mother life stress predicts adolescent self-regulation, and adoptive fathers’ stress predicts child stress sensitivity.