Objective: We tested the hypothesis that socioeconomic status (SES) would predict children's physical health problems at the end of kindergarten among children whose parent reported greater parent-child relationship (PCR) negativity and/or who exhibited greater parasympathetic (RSA) reactivity. We also tested whether RSA and PCR negativity mediated the SES-health association.
Methods: Data were collected from 338 children (mean [SD] age, 5.32 [.32] years) and their primary caregivers (87% biological mothers) during the fall and subsequent spring of kindergarten. In the fall, parents reported income and education level (SES) and PCR negativity, and RSA reactivity was assessed via a standardized challenge protocol for young children. In the fall and then spring, parents reported children's chronic medical conditions and physical health impairments. Multivariate regression was conducted within a structural equation-modeling framework to test hypotheses.
Results: Significant interactions were found between SES and PCR negativity (b = -0.074, p = .035) and between SES and RSA reactivity (b = 0.169, p = .019) as predicts children's spring health impairment, adjusting for health in the preceding fall. Lower SES was associated with greater health impairment among children whose parents reported more PCR negativity (b = -0.110, p = .024) and children who showed greater RSA reactivity (b = -0.106, p = .011). Socioeconomic status was unrelated to physical health at low PCR negativity or RSA reactivity. Mediation models were not supported.
Conclusion: Parent-child relationship quality and individual differences in stress reactivity may modulate the influence of SES on physical health in childhood.