Poster #21 - A Test of the Differential Susceptibility Hypothesis in a Longitudinal Study of African-Americans with Prenatal Substance Exposure

• In Event: 3-003 - Poster Session 09
  In Poster Session: PS 09 Section - Biological Processes: Psychophysiology

Integrative Statement

Introduction: Past research has shown a direct association between the quality of the parent-child relationship and children’s health and well-being. However, there is some evidence suggesting that magnitude and direction of the association may not be the same for all children. To elucidate the mechanisms underlying these individual differences, differential susceptibility theory (Belsky, Bakermans-Kranenburg, & van Ijzendoorn, 2007; Belsky & Pluess, 2009) posits that some children are more susceptible than others to both positive and negative rearing experiences “for better and for worse.” This study focuses on physiological indices of environmental susceptibility. In particular, it investigated whether individual differences in the activity of hypothalamic-pituitary-adrenocortical (HPA) axis to laboratory challenges interact with the quality of parent-child relationship to predict children’s physical and mental health problems. It also examined if the moderating effects of HPA axis functioning are sex-specific.
Method: Data were drawn from 554 African-American children (272 boys) who participated in a prospective longitudinal study of prenatal substance exposure. The quality of parent-child relationship (i.e., parent-child conflict and parent-child closeness) was assessed at 5 and 8 years. Children’s HPA reactivity was assessed at age 11 by using difference scores in salivary cortisol concentration levels 20 minutes before the start of the Trier Social Stress Task, and 20 minutes following the end of the task. Caregivers reported on children’s externalizing and internalizing behaviors at age 11 through using the Child Behavior Checklist (CBCL; Achenbach, 1992). The Disorders domain of the Child Health & Illness Profile-Adolescent Edition (CHIP-AE; Starfield et al., 1994, 2000) was used to assess children’s mental and physical illnesses, injuries, and impairments when they were 11, 12, 13 and 15 years old.
Results: Results of the regression analyses revealed robust positive associations between parent-child conflict and children’s internalizing (β = .26, p < .0001), and externalizing behaviors (β = .41, p < .0001). The association between early experience of parent-child closeness and children’s externalizing behavior was marginally significant (β = -.08, p = .06). Our findings also indicated a significant two-way interaction between parent-child closeness and cortisol reactivity in prediction of internalizing (β = .20, p = .002) and physical health problems (β = .19, p = .003), only among boys but not girls. Conducting simple slope analyses at +1SD and -1SD from the mean of cortisol reactivity (the moderator) revealed that low cortisol reactive boys who reported having closer relationships with their parents had fewer internalizing (Figure 1) and physical health problems than their peers with greater cortisol reactivity. Likewise, the highest rates of internalizing problems were observed among low cortisol reactive boys with greater experiences of disruptive family relationships (Figure 2).
Discussion: Consistent with the main predictions of differential susceptibility theory, our findings demonstrated that HPA axis functioning moderates the associations between parent-child conflict/closeness and later health outcomes. However, results suggested that individual differences in HPA axis functioning may not necessarily and globally serve as an indicator of susceptibility without considering the gender-specific implications, particularly among at-risk African-American children.

Authors

• Nila Shakiba, University of Utah
  Presenting Author

• Elisabeth Conradt, University of Utah
  Non-Presenting Author

• Bruce Ellis, University of Utah
  Non-Presenting Author

• Barry Lester, Brown University
  Non-Presenting Author