Background: The parent-child relationship is considered important for children's future conscience, and conscience is seen as protecting them from disruptive behavior problems, but specific mechanisms of this developmental process are rarely studied. Methods: This multi-trait multi-method study examined, in a longitudinal design, paths linking early maternal responsiveness to the child with the child's future conscience and disruptive behavior in 102 mother-child dyads. We tested a conceptual model where maternal responsiveness to the child, observed at 7 and 15 months, engenders a responsive stance in the child, observed at 25 and 38 months; that stance, in turn, becomes enduring and generalized, promoting multiple aspects of the child's conscience, observed at 52 months. In turn, conscience serves as a protective factor from disruptive behavior problems, rated by mothers and fathers at 67 months. Results: The postulated paths were examined using sequential regressions and mediation effects were tested using bootstrapping analyses. Child responsive stance at 25-38 months fully mediated the link between maternal responsiveness in infancy and conscience at 52 months, and conscience fully mediated the link between child responsive stance and future disruptive behavior at 67 months. Conclusions: Examination of developmental links among early maternal behavior, the child's responsive stance toward the mother, conscience, and disruptive behavior is a promising step toward elucidating mechanisms of children's adaptive and maladaptive trajectories.