Observed child behavioral self-regulation and maternal supportive parenting are associated with dynamic physiological stress reactivity in preschoolers.

This study sought to advance our understanding of how observed child self-regulation, parenting, and their interaction were associated with children's dynamic physiological stress reactivity indexed by respiratory sinus arrhythmia (RSA) reactivity trajectories. Participants were 85 three-year-old children (54% female) and their mothers oversampled for lower income, higher stressful life events, and higher child maltreatment risk. Child behavioral regulation, assessed as compliance and noncompliance, and maternal supportive parenting were observed during a challenging dyadic puzzle task. Results showed that child RSA exhibited quadratic change across the task on average, characterized by an expected initial decrease and subsequent recovery. Child behavioral regulation and its interaction with maternal supportive parenting were associated with interindividual differences in child RSA reactivity trajectories after controlling for child resting RSA. Children with higher compliance or lower noncompliance showed RSA decreases in response to task stressors but exhibited subsequent RSA recovery only when mothers displayed higher supportive parenting. Children with lower compliance or higher noncompliance displayed negligible RSA changes overall across the task, suggesting blunted or compromised RSA reactivity, regardless of supportive parenting levels. These findings demonstrate novel evidence that preschoolers' better behavioral regulation is related to their more adaptive physiological reactivity to stressors and that supportive parenting is needed to facilitate physiological recovery even in relatively better-regulated preschoolers. (PsycInfo Database Record (c) 2024 APA, all rights reserved).