Part of a prospective longitudinal study examining factors that account for developmental outcomes for high-risk children, this investigation focused on how successful adaptation at 12 and 18 months is related to adaptation at 24 months, 42 months, and 4.5 to 5 years of age. Assessments at each age were designed to indicate how the child was resolving salient developmental issues. To determine adaptation at 12 and 18 months, the quality of mother/child attachment was assessed. At 24 months, the children were videotaped with their mothers while performing tool-using/problem-solving tasks of increasing difficulty. At 42 months, children were observed with their mothers in four learning tasks requiring mothers to use teaching strategies. Finally, preschool children were rated on several dimensions, including agency, ego control, dependency on teachers for support and nurturance, social skills in the peer group, positive affect, negative emotional tone, and compliance with teachers' directions and suggestions. In addition, teachers were asked to complete the Preschool Behavior Questionnaire and a problem behavior scale. Children securely attached at 12 and 18 months were judged to deal more effectively with important developmental issues at later stages than were anxious-resistant and anxious-avoidant children. Results were also interpreted to provide some evidence for continuity of adaptation in high-risk children. (RH)