Social interactionist theory
||This article is written like a personal reflection or opinion essay rather than an encyclopedic description of the subject. (September 2009)|
Social interactionist theory is an explanation of language development emphasizing the role of social interaction between the developing child and linguistically knowledgeable adults. It is based largely on the socio-cultural theories of Soviet psychologist Lev Vygotsky.
Initial stages 
The Social Interactionist approach to language acquisition research has focused on three areas, namely the cognitive approach to language acquisition or the developmental cognitive theory of Jean Piaget, the information processing approach or the information processing model of Brian MacWhinney and Elizabeth Bates (the competition model), and the social interactionist approach or social interaction model of Lev Vygotsky (socio-cultural theory). Although the initial research was essentially descriptive in an attempt to describe language development from the stand point of social development, more recently, researchers have been attempting to explain a few varieties of acquisition in which learner factors lead to differential acquisition by the process of socialization; called the theory of “social interactionist approach”.
Socio-cultural theory 
Vygotsky, a psychologist and social constructivist, laid the foundation for the interactionists view of language acquisition. According to Vygotsky, social interaction plays an important role in the learning process and proposed the zone of proximal development (ZPD) where learners construct the new language through socially mediated interaction. Vygotsky's social-development theory was adopted and made prominent in the Western world though by Jerome Bruner  who laid the foundations of a model of language development in the context of adult-child interaction.
In contrast to the theoretical positions of behaviourism, the approach to language acquisition emphasizing that children are conditioned to learn language by a stimulus-response pattern with which it is sometimes confused, the social interactionist approaches rests on the premises of a social-cognitive model, emphasizing the child's construction of a social world which then serves as the context of language development.
It levels an outline of a language acquisition theory in combining of both the traditional behavioral and linguistic position in language production; the essentials of this theory, which differentiate it from a semantically based theory, are that the deepest level of representation specifies the communicative intent primarily and semantic content secondarily. Thus, within this theory the language acquisition can easily be realized differently in emphasizing the role of the environment in producing such differences, as is most often the case in child language and not infrequently the case in adult language. It is incumbent on this model as on any serious attempt to provide a theory of language acquisition, to answer questions about how the model accounts for changes in the child's knowledge with development, and how the model can be different to account for the adult's language system.
And as the behavioral approaches view that children as passive beneficiaries of the language training techniques employed by their parents and the linguistic approaches view that children as active language processors of whose maturing neural systems guide development; conversely, social integrationists communication enjoys a rather curious position in contemporary theories of language acquisition as a dynamic system where typically children cue their parents in to supplying the appropriate language experience that children require for language advancement. In essence, it turns in supplying of supportive communicative structure that allows efficient communication despite its primitives.
Current strand 
Social-interactionists, such as Jerome Bruner, Alison Gopnik, Andrew Meltzoff, Anat Ninio, Roy Pea, Catherine Snow, and Ernest Moerk theorize that interaction with adults plays an important part in children's language acquisition . However, some researchers such as Bambi B. Schieffelin and Elinor Ochs claim that the empirical data on which theories of social interactionism are based have often been over-representative of middle class American and European parent-child interactions. Anthropological studies of other human cultures, as well as low-educated Western families, suggests rather that many of the world's children are not spoken to in a manner documented for educated Western families, but nevertheless grow up to be fully fluent language users. Many researchers now take this into account in their analyses.
In addition, social interactionists criticize the claim made by Noam Chomsky according to which the linguistic input children are presented with by adults addressing them, is full of errors and discontinuities. Another argument of nativists on which interactionists provide contrary empirical evidence is the availability of negative feedback on, and corrections of, children's errors. Moerk (1994) conducted a meta-analysis of 40 studies and found substantial evidence that corrections do indeed play a role. From this work, corrections are not only abundant but contingent on the mistakes of the child. (see behavior analysis of child development).
- Gallaway, C. & Richard, B.J. 1994, Input and Interaction in Language Acquisition, Cambridge University Press, UK.
- Bruner, J. (1983). Child's Talk: Learning to Use Language" Oxford: Oxford University Press.
- Niedzielski, N.A. & Preston D.R. 2003, Folk Linguistics, Walter de Gruyter, Berlin.
- Moerk, E.L. (1983). A behavioral analysis of controversial topics in first language acquisition: Reinforcements, corrections, modeling, input frequencies, and the three-term contingency pattern. Journal of Psycholinguistic Research, 12, 129-155
- Moerk, E.L. (1994). Corrections in first language acquisition: Theoretical controversies and factual evidence. International Journal of Psycholinguistics, 10, 33-58