INTER-PARENTAL CONFLICT AND EARLY CHILDHOOD ADRENOCORTICAL ACTIVITY: A BIOSOCIAL FAMILY SYSTEMS APPROACH
Open Access
- Author:
- Hibel, Leah Corinne
- Graduate Program:
- Biobehavioral Health
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 22, 2009
- Committee Members:
- Dr Douglas Granger, Dissertation Advisor/Co-Advisor
Douglas A Granger, Committee Chair/Co-Chair
Elizabeth Susman, Committee Member
Laura Klein, Committee Member
Alan Booth, Committee Member - Keywords:
- inter-parental conflict
cortisol
mother
child - Abstract:
- It is universally accepted that family conflict exposure is a significant stressor in the lives of children and a driving force in the development of maladjustment. Unfortunately, little progress has been made in determining the mechanisms by which this occurs. Theoretical models of risky families highlight the potential for exposure to conflict and violence to dysregulate stress physiology, thus precipitating the development of mental and physical health problems. While past studies have found variations in intensity, and frequency of conflict, to be implicated in the development of pathology, recent mechanistic studies of stress physiology have failed to incorporate this level of detail in their examination of conflicted families. Furthermore, maternal behaviors have been shown to be critical in both facilitating the development of stress responsive physiological systems and mitigating the repercussions of conflict and violence exposure. The analyses presented in the following chapters will attempted to integrate a family systems approach along with a biosocial model of atypical development. Study 1 will examine the unique contributions of verbal and physical aggression on infant adrenocortical levels, reactivity, and recovery. Study 2 will examine the implications of chronic exposure to violence across the first two years of life on toddler adrenocortical levels, reactivity, and recovery. Data come from the Family Life Project, a multi-site study of child development in the context of non-urban poverty. At enrollment the sample (n = 1,292 mother-infant dyads; 49.4 % male) was racially diverse (41% African American) and from predominantly low-income (78% of the families were more than 200% below the poverty line), rural communities. During a home visit, the child’s saliva was sampled before, 20-minutes, and 40-minutes after standardized tasks designed to elicit the child’s emotional arousal and later assayed for cortisol. Mothers completed self-report measures of her and her partner’s verbal and physical aggression. Parenting behaviors were assessed via structured interview and mother-child interactions. Study 1 focused on the later infancy assessment when the child was 15 months old and Study 2 focused on data up to and including the toddler assessment when the child was 24 months old. Results from Study 1 found the confluence of inter-parental verbal aggression and maternal insensitivity to be related to heightened cortisol levels. Similarly, the combination of physical violence and low levels of maternal negative-intrusion was related to higher overall cortisol levels. Analyses for Study 2 revealed chronic exposure to inter-parental violence to be related to heightened cortisol reactivity. However, early maternal sensitivity was found to completely buffer children from heightened cortisol reactivity. In other words, children exposed to maternal sensitivity during early infancy (at approximately 7-months) did not exhibit high cortisol reactivity even when exposed to chronic inter-parental violence. Findings are discussed within the framework of current biopsychosocial and risky family theories.