This thesis examines two major theories of child development. These are the social-interactive account of children's cognitive growth of the Troica (Vygotsky, Luria and Leont'ev) and Piaget's approach which evolved from an individualistic to a more social-interactive approach. A synthesis of these ideas is used as a nucleus for suggestions for child education relevant to the predicted post-industrial, and subsequent post-service, economy. For the Troica, human development differed from that of animals because of mediation through language. Language enabled people to establish connections between stimulus and response and so transform sensations into thought. Language is the principal social activity leading to the development of both culture and child. The view that language gave humans a 'tool' for communication and regulation of behaviour was basic to their social- interactive approach to cognitive growth. Piaget's early biological studies laid the foundation of his concept of stages in child development, based on intellectual and physical adaptation to the environment. His constructivist hypothesis was more individualistic than the activity concept of the Troica; the roles of language and contact with adults in children's development being minimised before about 1960. There is a distinct change in Piaget indicating an awareness of the social nature of children's living and its implications for their cognitive growth. Among Piagetians, the later views of both Case and Halford also indicate a growing acceptance of a social-interactive concept of developing cognition. Four major themes emerge from the findings of both the Troica and Piaget. These are language, adult-child contact, egocentricity and activity. The efficacy of a number of research issues in investigating these themes is examined. The contributions of other scholars both Soviet and Western in this field are also considered. Several Western writers have expressed their concern about the psychological, social and educational implications of the ongoing technological revolution. In this thesis the view is taken that consideration of the findings of earlier researchers, substantiated by current research into the nature of children's cognition is essential in devising a form of education pertinent to the future. Three major findings arise from this study: Although there are considerable differences in the accounts of children's cognitive growth hypothesised by the Troica and Piaget, a synthesis of many of their ideas and their relevance to current educational practice is evident; The importance of social interaction in cognitive development, which was crucial to the view of the Troica, is becoming more widely acknowledged by research scholars; Because the Troica worked together as a unit, the holistic nature of their findings is distorted by the tendency of scholars to consider Vygotsky's work in isolation. This approach ignores the important contributions which Luria and Leont'ev made to the group's efforts in devising a new psychology based on social interaction which incorporated the socio- historical development of both society and its members.