How can I model an acquistion?

Non-nativist theories include the Competition model and Social interactionism. Social-interactionists, like Snow, theorize that adults play an important part in children's language acquisition. However, some researchers 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. Various anthropological studies of other human cultures, as well as anecdotal evidence from western families, suggests rather that many, if not the majority, of the world's children are not spoken to in a manner akin to traditional language lessons, but nevertheless grow up to be fully fluent language users. Many researchers now take this into account in their analyses. Furthermore, as any parent knows, children often pay scarce attention to what they are told to say, instead sticking to their own ungrammatical preferences.