Briefly describe three models of human development. How well does each account for the development of language?

So much of human development involves interaction with others therefore the medium of language whether spoken, written or gestured, plays a central role in our lives.  But what is language, how can it be defined and what are its major components? How does a human develop and acquire language.  What do three of the main models in Psychology think of language acquisition?  In this essay I will briefly discuss the three main models of human development and then will attempt to answer the question of how language is developed and acquired using the views of the main models and their theorists….(short extract)