A diverse sample of 239 primarily low-income couples participated in a random controlled trial of the Supporting Father Involvement couples group intervention. In this report, we examined the value of adding measures of fathers' attachment style and parenting to mothers' measures in order to explain variations in children's behavior problems. We also tested the hypothesis that the link between intervention-induced reductions in couple conflict and reductions in anxious/harsh parenting can be explained by intervention effects on parents' attachment insecurity or on anxiety and depression. Fathers' attachment security and parenting behavior added significantly to mothers' in accounting for children's internalizing and externalizing problem behaviors. Fathers' anxious attachment style and anxiety/depression mediated the link between post-intervention reductions in parental conflict and anxious/harsh parenting. For mothers, only improvements in attachment security accounted for those links. The findings support the need for attachment researchers to consider the contributions of both parents to their children's development.
Keywords: Fathers; attachment; child behavior problems; family systems; mediation.