Predictors and concurrent correlates of childhood-onset and
adolescent-onset antisocial behavior were studied in a sample of 165 boys
and 151 girls, followed from age 6 to age 15. An integrated general growth
mixture model was used to determine the number and shape of developmental
trajectories of antisocial behavior exhibited by boys and girls.
Associations of these trajectories with trajectories of
attention-deficit/hyperactivity (ADH) problems and deviant peer
affiliation were examined. A childhood-onset, an adolescent-onset, and a
low antisocial behavior trajectory were identified. A minority of the
sample (11%), mostly males, followed the childhood-onset trajectory. This
trajectory was predicted by prior membership in the high ADH trajectory in
childhood. The adolescent-onset trajectory (46%) was associated with
increases in friends' antisocial behavior but not with ADH problems.
Most females (60%) followed the low antisocial trajectory. A substantial
proportion of females, however, followed the childhood (5%) and
adolescent-onset trajectories (35%). The male–female ratios in the
childhood and adolescent-onset trajectories were similar. The results
largely supported theories that distinguish between childhood and
adolescent onsets of antisocial behavior, but they did not suggest that
boys and girls differ in the age of onset of antisocial behavior.This study was supported by grants from the
Conseil Québécois de la Recherche Sociale and the Canada
Social Sciences Research Council. We thank Ted Barker and Sara Pedersen
for their helpful comments and suggestions on this
manuscript.