Lev Semionovich Vygotsky, 1896-1934, was a Soviet psychologist who was active in a number of fields during his academic career, such as the psychological analysis of art and fables, child psychology, problems of deaf and retarded children, and the psychological analysis of brain-injured adults (Vygotsky). His work on language and linguistic development is based on his supposition that higher cognitive processes are a product of social development (Vygotsky). "Though and Language," 1937, "Selected Psychological Studies," 1956, and "Development of the Higher Mental Processes," 1960, are among his major works (Vygotsky).

             Drawing on early research into the rules and development of tool-use and sign-use behavior, Vygotsky turned to symbolic processes in language, emphasizing the semantic structure of words and the way in which word meanings change from emotive to concrete, and then eventually becoming more abstract (Vygotsky). According to Vygotsky: .

             "Every function in the child's cultural development .

             appears twice: first, on the social level, and later, .

             on the individual level; first, between people .

             (interpsychological) and then inside the child .

             (intrapsychological). This applies equally to voluntary .

             attention, to logical memory, and to the formation of .

             concepts. All the higher functions originate as actual .

             relationships between individuals" (Social). .

             Another aspect of Vygotsky's theory is the idea that the potential for cognitive development depends upon the "zone of proximal development," or ZPD, which is a level of development that is reached when children engage in social behavior (Social). Therefore, full development of the ZPD depends upon full social interaction, in other words, the range of skill that can be developed with adult guidance or peer interaction exceeds what the child can be attain alone (Social). .

             Vygotsky attempted to explain consciousness as the end product of socialization, for example, in learning a language, the first utterances with peers or adults are for the purpose of communication, however once these are mastered, they become internalized and allow "inner speech" (Social).