Parasympathetic and Sympathetic Reactivity and Their Coordination as Antecedents to the Cascade of Children's Callous-Unemotional Traits and Later Psychological Adjustment.

Abstract

This study examined whether a mediational cascade involving children's respiratory sinus arrhythmia (RSA) reactivity to a series of cognitive and socio-evaluative stressors, their callous-unemotional (CU) traits, and psychological adjustment was moderated by their cardiac pre-ejection period (PEP) reactivity. Using a multi-method, multi-informant design, 238 mothers and their preschool children (Mage = 4.38, 52% female; 68% White; 18% Black; 14% Multiracial or another race; and 16% Latinx) participated in three annual timepoints from 2018 to 2022. Findings indicated that children's CU traits at Wave 2 mediated the association between dampened RSA reactivity at Wave 1 and their Wave 3 externalizing and social difficulties. Consistent with hypoarousal models of CU traits, these pathways were stronger for children with dampened PEP reactivity to the stressors.