Autonomic nervous system activity moderates associations between temperament and externalizing behaviors in early...

Temperamental risk, such as surgency, negative affect, and poor effortful control, has been posited as a predictor of externalizing symptom development. However, autonomic nervous system (ANS) activity underlying processes of reactivity and regulation may moderate associations between early temperament and later externalizing behaviors during early childhood. The aim of the present study was to examine how interactions between resting sympathetic (SNS) and parasympathetic (PNS) activity at age 5 may moderate associations between temperamental risk at age 3 and externalizing behavior at age 6 (n = 87). Results demonstrate different interactions between resting ANS activity and temperamental risk to predict externalizing behaviors. For children with lower SNS activation at rest, surgency was positively associated with externalizing behaviors. Negative affect was positively associated with externalizing behaviors except when there were either high levels of SNS and PNS activity or low levels of SNS and PNS activity. Effortful control was not associated with externalizing behaviors, though SNS and PNS activity interacted to predict externalizing behaviors after accounting for effortful control. Taken together, the results highlight the importance to examine multisystem resting physiological activity as a moderator of associations between temperamental risk and the development of externalizing  behaviors.