Children in families in the control group and the intervention nonengager group showed relatively low levels of problem behavior over time. In contrast, for one-FCU engagers, those children in the intervention group showed considerably less growth in oppositional behavior than did those defined as potential engagers in the control group (B= −.22, p< .01). The effect size comparing the intervention group with the control group from ages 2 to 5 was small to medium (d = .44). Moreover, the indirect effect of the FCU on age 7.5 teacher-reported oppositional behavior through growth of parent-reported disruptive behaviors was also significant (indirect B = −.116, p< .05), with an effect size of d = .23.
