LOW RESTING HEART-RATE AT AGE 3 YEARS PREDISPOSES TO AGGRESSION AT AGE 11 YEARS - EVIDENCE FROM THE MAURITIUS CHILD HEALTH PROJECT

Objective: Previous studies indicate that low resting heart rate is pr obably the best-replicated biological correlate of childhood antisocia l and aggressive behavior. Nevertheless, there have been few longitudi nal tests of this relationship, little control over potential confound s and mediators, and no test of its cross-cultural generalizability. T his study tests the hypothesis that low resting heart rate at age 3 ye ars predicts aggression at age ii years. Method: Resting heart rate at age 3 years was assessed in 1,795 male and female children from Mauri tius. Aggressive and nonaggressive forms of antisocial behavior were a ssessed at age 11 years using the Child Behavior Checklist. Results: A ggressive children had lower heart rates than nonaggressive children ( p < .001). Conversely, those with low heart rates were more aggressive than those with high heart rates (p < .003). There were no interactio ns with gender or ethnicity. Evidence was found for specificity of low heart rate to aggressive forms of antisocial behavior. Group differen ces in heart rate were not attributable to 11 biological, psychologica l, and psychiatric mediators and confounds. Conclusions: It is conclud ed that low resting heart rate, a partly heritable trait reflecting fe arlessness and stimulation-seeking, is an important, diagnostically sp ecific, well-replicated, early biological marker for later aggressive behavior.