Respiratory sinus arrhythmia as a moderator of early maltreatment effects on later externalizing problems.

Physiological regulation may interact with early experiences such as maltreatment to increase risk for behavior problems. In the current study, we investigate the role of parasympathetic nervous system regulation (respiratory sinus arrhythmia [RSA] at rest and in response to a frustration task) as a moderator of the association between early risk for maltreatment (i.e., involvement with Child Protective Services; CPS) and externalizing behavior problems in middle childhood. CPS involvement was associated with elevated externalizing problems, but only among children with average to high RSA at rest and average to high RSA withdrawal in response to frustration. Effects appeared to be specific to CPS involvement as the association between cumulative risk (i.e., nonmaltreatment experiences of early adversity) and externalizing problems was not significantly moderated by RSA activity. These findings are consistent with the theoretical idea that the consequences of early maltreatment for later externalizing behavior problems depend on children's biological regulation abilities.