The authors studied receptive cooperation--a willing, eager stance toward parents--in 15-month-old children (N=101) in broadly ranging contexts. Children's anger proneness and parents' responsiveness (both observed at 7 months) and children's attachment security (assessed in Strange Situation at 15 months) were examined as predictors of children's receptive cooperation at 15 months. In mother-child dyads, secure attachment was strongly associated with children's higher receptive cooperation. Maternal responsiveness in infancy also promoted children's future receptive cooperation, but its impact was moderated by child anger: Responsiveness had a positive effect for children who as infants were highly anger prone. In father-child dyads, the negative effect of anger proneness on receptive cooperation with father was significantly amplified for insecure children. Mother's responsiveness and child's secure attachment to the mother promoted child receptive cooperation with the father, but there were no similar effects for fathers.