Relational victimization typically emerges first during the elementary school period, and has been associated with increased levels of internalizing symptoms in children. Individual differences in autonomic nervous system functioning have been suggested as a potential factor linking social stressors and internalizing symptoms. The aim of this study was therefore to examine whether heart rate and heart rate variability mediated the association between relational victimization and internalizing symptoms in 373 mainstream elementary school children. Children were assessed in 2015 (T0; Grades 3–5, M age = 9.78 years, 51% boys) and reassessed in 2016 (T1). Heart rate and heart rate variability were assessed during a regular school day at T1. A multi-informant (teacher and peer report) cross-time measure of relational victimization, and a multi-informant (self- and teacher report) measure of internalizing problems at T1 was used. Results showed that heart rate variability, but not heart rate, mediated the association between relational victimization and internalizing symptoms. This study provides tentative support that in children from a general population sample, a psychobiological factor may mediate the association of relational victimization with internalizing symptoms.

Dysregulated autonomic nervous system (ANS) activity has been associated with adolescent risk-taking and internalizing behavior, but previous results in community samples have been mixed. We investigated whether ANS activity was associated with higher risk-taking and internalizing behavior in young adolescents (age 11/12; n = 875), and whether adolescents’ gender, parents’ parenting style or a combination of both moderated these associations. Adolescents and their parents were recruited as part of the population-based, longitudinal Amsterdam Born Children and their Development (ABCD) study. Risk-taking behavior was assessed with the Balloon Analogue Risk Task and the personality characteristics sensation seeking and impulsivity, measured with the Substance Use Risk Profile Scale (SURPS). Internalizing behavior was assessed via the SURPS subscales anxiety sensitivity and hopelessness. Authoritative (AUTH-SW) and authoritarian (AUTH-S) parenting styles were measured with the Parenting Styles and Dimensions Questionnaire. Resting ANS activity was assessed via heart rate and respiratory sinus arrhythmia (RSA). Hierarchical, multivariable regression analyses showed higher RSA, but not heart rate, being associated with higher risk-taking behavior and sensation seeking. The associations between ANS activity and risk-taking variables were not significantly moderated by gender, parenting, or interactions between gender and parenting. Our findings suggest that RSA activity may be a relevant factor in mild to moderate risk-taking behavior in adolescents from the general population, regardless of their gender or the type of parenting they experience.