Dynamic skill theory was utilized to explain the multiple mechanisms and mediating processes influencing development of self-regulatory and language skills in children at 14, 24, and 36 months of age. Relations were found between family risks, parenting-related stresses, and parent-child interactions that contribute either independently or through mediation to the child's acquisition of self-regulatory skills even when accounting for the influence of language development. Variation in impacts between control and Early Head Start (EHS) intervention samples was compared to explore the sequence of developmental mechanisms over time. Findings indicate that EHS protects parenting, child language, and self-regulatory development from the effects of demographic risks and parenting stress, and thus supports parents to raise healthy children.