Preschoolers' everyday conflict at home and diurnal cortisol patterns.

OBJECTIVE Early life family conflict is associated with physical health problems later in life, but little is known about the biological pathways through which conflict at home exerts it deleterious effects on health. The goal of this study was to investigate the associations between naturalistically assessed conflict in everyday family environments and diurnal cortisol in preschool-aged children. DESIGN Forty-four children aged 3-5 from two-parent families provided six saliva samples per day over 2 days from a Saturday morning through Sunday night. For a full day on either Saturday or Sunday, children wore a child version of the Electronically Activated Recorder, a digital voice recorder that records ambient sounds while participants go about their daily lives. Parents provided reports of child externalizing behaviors as well as daily reports of child conflicts. MAIN OUTCOME MEASURES Diurnal salivary cortisol over the two weekend days of the study. RESULTS Greater Electronically Activated Recorder-assessed child conflict at home was associated with children having lower cortisol at wakeup (p < .009) and flatter diurnal cortisol slopes (p < .007). These associations remained significant even after controlling for parent reports of child externalizing behaviors, parent reports of daily child conflicts, and child age and sex. CONCLUSION These findings indicate that taking into consideration everyday conflicts at home may be key to our understanding of stress-health links in young children.