Physiological and behavioral regulation in two-year-old children with aggressive/destructive behavior problems

A sample of 99 two-year-old children was selected on the basis of parents' responses to two administrations of the Child Behavior Checklist for two- t o three-year-olds. Forty-nine of these children displayed symptoms of aggre ssive/destructive (externalizing) problems that were in the borderline clin ical range (labelled "high risk") and 50 children displayed few such sympto ms ("low risk"). The children were assessed in a series of laboratory proce dures that were intended to be emotionally and behaviorally challenging, du ring which time heart rare was recorded and behavior was observed. To asses s physiological regulation, resting measures of heart period and respirator y sinus arrythmia (RSA), and heart period change and RSA suppression were d erived from these procedures. To assess emotional and behavioral regulation , children's affect and on-task versus types of off-task behaviors were mea sured. Results indicated that children in the high-risk group did not diffe r from children in the low-risk group on the resting measure of heart perio d. Boys displayed lower heart rate than did girls, regardless of risk group . However, boys in the low-risk group differed from boys in the high-risk g roup in terms of resting measures of RSA. Children in the high-risk group d id display significantly and consistently lower RSA suppression (physiologi cal regulation) during the challenging situations than did the children in the low-risk group. High-risk children displayed more negative affect and d ysregulated emotion regulation behaviors than did the low risk children. Th ese findings are discussed in terms of the development of behavioral and em otional regulation that underlie adaptive versus maladaptive behavior.