| The present longitudinal study examined diurnal cortisol patterning over time among 65 children, 41 children with histories of foster care and 24 comparison children, in relation to social-cognitive and behavior regulation outcomes. Diurnal cortisol patterns were assessed via assay of wake-up and bedtime saliva samples collected over 2-3 consecutive days at two developmental timepoints: infancy/toddlerhood (Time 1) and early school age (Time 2). Social-cognitive and behavior regulation outcomes were assessed at Time 2. Structural equation models of latent difference scores revealed that adopted and comparison children's wake-up cortisol values did not differ at Time 1 or 2, but adopted children showed less of a decrease in cortisol across the day at Time 1 relative to comparison children. Participation in an early intervention program, attachment disorganization, and foster care placement instability were also examined as predictors of diurnal cortisol patterns. With regard to social-cognitive outcomes, steeper diurnal change in cortisol at Time 2 was associated with higher cognitive flexibility and theory of mind abilities, when controlling for several demographic variables. These results could inform early intervention programs by providing a better understanding of risk factors that predict flatter diurnal cortisol patterns, and the specific outcomes associated with flatter diurnal cortisol patterns. |
