The Impact of Household Stability on HPA Axis Function and Emotional Responses in Early Childhood

The present study examined how household unpredictability, as measured by the CHAOS scale, influences to hypothalamic-pituitary-adrenal (HPA) axis functioning and emotional responses in early childhood. Despite a growing body of research linking household chaos to child development outcomes, few studies have studied stress reactivity in young children. To address this gap, we employed a stress paradigm involving a finger prick procedure and observed distress coding in a sample of 44 children (M = 5.44 years). Salivary cortisol was collected at three timepoints to quantify HPA axis activation via area under the curve with respect to increase (AUCi). Hierarchical regressions tested whether household chaos predicted cortisol reactivity (Hypothesis 1), observed distress (Hypothesis 2), and whether cortisol mediated the relationship between chaos and distress (Hypothesis 3), while controlling for age, sex, threat, and deprivation. Results indicated no significant associations between household chaos and cortisol or distress, nor evidence for mediation via cortisol. Exploratory analyses revealed inconsistencies in cortisol collection across participants and emphasized limitations in salivary cortisol sampling. These findings suggest that household chaos may not influence HPA axis reactivity or emotional distress in early childhood through the pathways proposed, suggesting that such effects may emerge later in development or operate through alternative mechanisms.