Differences in mother-child and father-child RSA synchrony: Moderation by child self-regulation and dyadic affect.

Parents and preschoolers show respiratory sinus arrhythmia (RSA) synchrony, but it is unclear how child self-regulation and the dyadic affective climate shape RSA synchrony and how synchrony differs for mothers and fathers. We examined child average RSA, externalizing problems, and dyadic positive affect as moderators of the synchrony of dynamic, within-epoch child and parent RSA reactivity during a challenging task. Mothers (N = 82) and fathers (N = 60) oversampled for familial risk participated with their 3-year-olds. For mothers, when children showed either higher externalizing or lower average RSA, negative RSA synchrony was observed as dynamic coupling of maternal RSA augmentation and child RSA withdrawal, suggesting inadequate support of the child during challenge. However, when children showed both higher externalizing and lower average RSA, indicating greater regulatory difficulties overall, positive synchrony was observed as joint RSA withdrawal. The same patterns were found for father-child RSA synchrony but instead with respect to the moderators of higher externalizing and lower dyadic positive affect. Findings suggest moderators of RSA synchrony differ by parent and shared positive affect plays a robust role in fathers' RSA reactivity and synchrony. Mothers may be more attuned to children's regulatory capacities, whereas fathers may be more influenced by the immediate behavioral context.