Interactions between Genetic, Prenatal, Cortisol, and Parenting Influences on Adolescent Substance Use and Frequency: A TRAILS Study

<b><i>Introduction:</i></b> Dynamic relations between genetic, hormone, and pre- and postnatal environments are theorized as critically important for adolescent substance use but are rarely tested in multifactorial models. This study assessed the impact of interactions of genetic risk and cortisol reactivity with prenatal and parenting influences on both any and frequency of adolescent substance use. <b><i>Methods:</i></b> Data are from the TRacking Adolescents’ Individual Lives Survey (TRAILS), a prospective longitudinal, multi-rater study of 2,230 Dutch adolescents. Genetic risk was assessed via 3 substance-specific polygenic scores. Mothers retrospectively reported prenatal risk when adolescents were 11 years old. Adolescents rated their parents’ warmth and hostility at age 11. Salivary cortisol reactivity was measured in response to a social stress task at age 16. Adolescents’ self-reported cigarette, alcohol, and cannabis use frequency at age 16. <b><i>Results:</i></b> A multivariate hurdle regression model showed that polygenic risk for smoking, alcohol, and cannabis predicted any use of each substance, respectively, but predicted more frequent use only for smoking. Blunted cortisol reactivity predicted any use and more frequent use for all 3 outcomes. There were 2 interactions: blunted cortisol reactivity exacerbated the association of polygenic risk with any smoking and the association of prenatal risk with any alcohol use. <b><i>Conclusion:</i></b> Polygenic risk seems of importance for early use but less so for frequency of use, whereas blunted cortisol reactivity was correlated with both. Blunted cortisol reactivity may also catalyze early risks for substance use, though to a limited degree. Gene-environment interactions play no role in the context of this multifactorial model.

Developmental Perspectives on Parenting

This chapter discusses two leading middle-level theories within evolutionary psychology, which attempt to explain both how and why parenting influences child development across the life span. First, it presents an overview of one of the most influential evolutionary theories in developmental psychology: John Bowlby’s attachment theory. Attachment theory revolutionized the way people understand the nature of the parent–child bond, framing the parent as not just a provider of physical needs but also as a secure base for emotional and psychological needs. These early-life bonds between the caregiver and infant are further proposed to form the basis for relationship attachments across the life span. Next, the chapter addresses how competing strategies toward resource allocation can influence individual differences in parental investment and sensitivity. According to life history theory, differences in the caregiving environment, in turn, promote the formation of distinct reproductive strategies, resulting in behavioral, social, and physiological differences across child development.

Harsh Parenting and Child Brain Morphology: A Population-Based Study

Evidence suggests that maltreatment shapes the child’s brain. Little is known, however, about how normal variation in parenting influences the child neurodevelopment. We examined whether harsh parenting is associated with the brain morphology in 2,410 children from a population-based cohort. Mothers and fathers independently reported harsh parenting at child age 3 years. Structural and diffusion-weighted brain morphological measures were acquired with MRI scans at age 10 years. We explored whether associations between parenting and brain morphology were explained by co-occurring adversities, and whether there was a joint effect of both parents’ harsh parenting. Maternal harsh parenting was associated with smaller total gray (β = −0.05 (95%CI = −0.08; −0.01)), cerebral white matter and amygdala volumes (β = −0.04 (95%CI = −0.07; 0)). These associations were also observed with the combined harsh parenting measure and were robust to the adjustment for multiple confounding factors. Similar associations, although non-significant, were found between paternal parenting and these brain outcomes. Maternal and paternal harsh parenting were not associated with the hippocampus or the white matter microstructural metrics. We found a long-term association between harsh parenting and the global brain and amygdala volumes in preadolescents, suggesting that adverse rearing environments common in the general population are related to child brain morphology.

Parenting and Offspring Brain Development: What Do We Know?

Parenting has been robustly associated with offspring psychosocial development, and these effects are likely reflected in brain development. However, the claim that parenting influences offspring brain development in humans, as measured by structural and functional Magnetic Resonance Imaging (MRI), is subject to numerous methodological limitations. To interpret the state of the parenting and brain development literature, we review these limitations. Four limitations are common. First, most literature has been cross-sectional. Where longitudinal, studies rarely included multiple assessments of brain structure or function, precluding measurement of actual brain development. Second, parenting has largely been measured via selfor parent-report, as opposed to observational assessment. Third, there has been a focus on extreme forms of developmental adversity which do not necessarily lie on a continuum with normative parenting. Fourth, although not a limitation per se, studies have generally focused on negative as opposed to positive parenting behaviours. While not all studies are subject to all these limitations, the study of parenting in relation to offspring brain development is in its infancy.

Exploring Parenting Influences: Married African American Fathers’ Perspectives

This qualitative study sought to understand married, resident African American fathers’ perceptions about parenting influences. Specifically, this study explored fathers’ perceptions about sources and/or experiences that informed their approaches and attitudes about parenting. Social learning theory, the modeling and compensation hypothesis, as well as literature on the intergenerational transmission of parenting served as theoretical frameworks. Eight fathers participated in semi-structured interviews. One main theme and four subthemes emerged from the data. Findings indicated that a number of influences including but not limited to experiences from their family of origin informed current parenting approaches and attitudes.

Early experiences of insensitive caregiving and children's self-regulation: Vagal tone as a differential susceptibility factor

A considerable body of research has linked parenting to the development of children's self-regulation. However, few studies have considered different domains of self-regulation, the effects of early caregiving behaviors, and whether or not parenting influences children equally. Towards this, the present investigation tested how early maternal insensitivity was associated with difficulties in children's effortful control in early childhood and their regulation of negative emotions during the early school years. Further, we tested whether children's resting vagal tone may operate as a susceptibility factor, consistent with differential susceptibility models. The sample included 220 pairs of mothers and their children who were assessed at 18 months, 3.5 years and 5 years of age. Laboratory visits consisted of observational paradigms and survey assessments. Early maternal insensitivity at 18 months of age forecasted difficulties with effortful control at age 3.5. Moreover, effortful control at age 3.5 was associated with greater anger, but not sadness, regulation at age 5. Consistent with differential susceptibility, children's resting vagal tone at 18 months of age moderated the role of early caregiving on children's effortful control. The findings suggest that low resting vagal tone may operate as a differential susceptibility factor in process models testing associations between early caregiving environments and children's self-regulation.

Parenting and Relational Aggression

Many studies have considered whether parents play a role in either promoting or moderating their children’s engagement in relational aggression (also known as indirect or social aggression). This is not surprising, given the consistent parenting correlates of physical aggression in prior research. There is evidence of fairly regular correspondence between children’s relational aggression and their parenting and home environment. We comprehensively consider the range of existing studies that have considered parenting correlates, and we group similar studies together. While most studies have utilized social learning theory as the foundation for empirical inquiry, there are researchers who consider alternative theories (attachment, social cognition) and emphases (e.g., direct vs. indirect effects of parenting) in their consideration of individual differences for relational aggression. Parenting influences are also qualified by children’s differential susceptibilities (e.g., biological or temperamental variations). In considering all of these issues, the contrast with physical aggression is carefully observed.