Sex Differences in the Contribution of Respiratory Sinus Arrhythmia and Trauma to Children's Psychopathology.

Respiratory sinus arrhythmia (RSA), a marker of parasympathetic activity, has been shown to moderate the relation between adversity and child behavioral outcomes; however, this work has been conducted in primarily Caucasian samples and limited in focus to family-level adversity. The current analysis extends the previous literature to examine the co-contribution of exposure to potentially traumatic events (PTEs), baseline RSA, and RSA withdrawal to internalizing and externalizing behavior in a sample of primarily African American youth (n = 92) recruited using neighborhood mapping techniques from communities high in epidemiological indicators of adversity. Exposure to PTEs was associated with lower baseline RSA. Complex interactions were observed between sex of the child, baseline RSA and RSA withdrawal, and PTE exposure predicting to internalizing behaviors. Among girls with high (4+) levels of PTEs, high baseline RSA and RSA withdrawal predicted higher internalizing; for RSA withdrawal only, the inverse was observed for girls with low PTE exposure, for whom high RSA withdrawal predicted lower internalizing. No associations were observed from RSA to externalizing, or among boys to internalizing. Findings are consistent with distinct patterns among primarily African American samples and suggest the need for sex-specific conceptualizations of the link between environmental adversity, physiological reactivity, and internalizing behaviors.