Parent-Child Relationships and Child Physical Health and Stress-Related Physiology: A Daily Diary Investigation
Poor parent-child relationships in childhood have been linked to later adult physical health problems, such as heart disease, cancer, and depression (Miller et al.,2011). Yet, little is known about the immediate effects of the parent-child relationship on child physical health. Exposure to stressors in the family, such as harsh parenting or cold parent-child relationships, may give rise to later health problems through their impact on the stress-related physiology, such as the operation of the hypothalamic-pituitary-adrenocortical (HPA) system and subsequent disruption of immune processes (Repetti et al., 2011). This study uses a daily diary approach 1) to investigate the links between daily negative parent-interactions and both child physical health and cortisol (a biomarker of HPA axis functioning) and 2) to test if these relations are moderated by child gender, parent gender, and the frequency of negative parent-child interactions across the week.
This study uses a sample of 131 parent-youth dyads who participated in an 8 day daily diary study that explored the links between work, family and health. Cortisol, a hormonal by product of the HPA system, was collected on 4 study days. Measures included negative parent-child interactions, child physical health symptoms (e.g., having a cold, etc.), and three cortisol indicators of HPA functioning (levels of cortisol before dinner and at bedtime, and the slope from bedtime to dinner). Data were analyzed using multilevel models with days (level 1, within-person) nested within individuals (level 2, between-person). Level 1 captured each person’s deviation from their own average level of negative interactions on each day. Level 2 captured each person’s average level of negative interactions across all 8 days. Control variables include child age, gender, time of cortisol sample, medication use, and race.
The associations between negative parent-child interactions and child health were moderated by child gender, parent gender, and between –person levels of negative interactions. On days when girls (but not boys) experienced more negative interactions than usual, girls experienced more physical health symptoms and flatter (e.g., less healthy) cortisol slopes (within-person). Children who had negative interactions with their mothers (but not fathers) were more likely to experience physical symptoms and had higher (e.g., less healthy) levels of cortisol before dinner and at bedtime (between-person). Daily negative interactions with mothers were also associated with flatter child cortisol slopes (within-person). A significant between by within interaction was found for negative experiences and child physical symptoms and bedtime cortisol levels, suggesting that the health of children who experience fewer negative interactions across the week may be more sensitive to by daily deviations in negative interactions than children who experience negative interactions more frequently.
These findings suggest that negative interactions between parents and their children have important implications for child physical health, although more so for specific groups than others. Family-based interventions aimed to interrupt negativity in the parent-child relationship may be particularly effective at promoting child health if they target girls and mothers and if they occur before negative interactions become normalized within the parent-child relationship.