Cortisol Levels and Child Care Quality in Australian 3-5 Year Old Children: Cortisol Changes and the Quality of Child Care in Australian Preschool and Kindergarten Children

Many consider child care a risk factor for poor child outcomes, particularly those who believe that parental rearing is essential for children's well-being. It is possible to identify the immediate impact of the child-care environment on children using biomarkers of stress such as cortisol. Children (aged 3–6 years) attending a range of child-care centers of varying quality participated in the study. Center quality was measured using the Australian national quality assurance system. Salivary cortisol levels were obtained from the children and the change in cortisol across the child-care day was determined. Specific trajectories of cortisol were identified and used in the analysis. Children who demonstrated a normative decline in cortisol across the childcare day were consistently associated with high-quality child-care programs, whereas those demonstrating an increase in cortisol were more likely associated with unsatisfactory programs. Cortisol changes were more susceptible to changes in quality rated by those principles linked to the relationship dimensions of quality service. Thus, program quality was associated with different cortisol trajectories; in particular, children attending low-quality services are more likely to demonstrate cortisol trajectories that are linked in the extant research with poorer outcomes. We argue that this result has important implications for micro systems of child care.