Language acquision device

There are many facts that are intriguing about the language. The fact that all humans have it, and all non-humans do not. The fact that children are able to learn it very quickly. The fact that there exist so many languages and children of all countries are able to acquire them at the same speed. This list can go on and on. 

The way in which children acquire language is at the centre of a debate. Learning theorists such as Skinner (1957) maintained that language is acquired through reinforcement. Chomsky (1959) argued that language was far too complex to be learned so competently in such a short space of time, by cognitively immature toddlers, merely by reinforcement. Chomsky proposed that each of us has a Language Acquisition Device (LAD) – what he sometimes called a “little black box” – that starts functioning when we are still infants.

The Language Acquisition Device (LAD) is a hypothetical brain mechanism that Noam Chomsky postulated to explain human acquisition of the syntactic structure of language. This mechanism endows children with the capacity to derive the syntactic structure and rules of their native language rapidly and accurately from the impoverished input provided by adult language users. The device is comprised of a finite set of dimensions along which languages vary, which are set at different levels for different languages on the basis of language exposure. The LAD reflects Chomsky's underlying assumption that many aspects of language are universal (common to all languages and cultures) and constrained by innate core knowledge about language called Universal Grammar.

Chomsky motivated the LAD hypothesis by what he perceived as intractable complexity of language acquisition, citing the notion of "infinite use of finite means" proposed by Wilhelm von Humboldt. At the time it was conceived (1957–1965), the LAD concept was in strict contrast to B.F. Skinner's behavioral psychology which emphasized principles of learning theory such as classical and operant conditioning and imitation over biological predisposition.

By the 1970s, further research at MIT, where Noam Chomsky taught linguistics, was starting to move away from the theory of a language acquisition device. As new languages were studied in depth, the universal characteristics Chomsky hypothesized did not emerge. In the 1990s, Chomsky moved to an innate principles-and-parameters-of-constraints framework to explain the language acquisition of infants. Most linguists found this theory plausible. Linguists have continued their research into the language habits of children, however, and the rapidity and ease with which children acquire language has not yet been fully explained.

To sum up, The Language Acquisition Device, or LAD, is part of Chomsky's acquisition hypothesis. The LAD is a system of principles that children are born with that helps them learn language, and accounts for the order in which children learn structures, and the mistakes they make as they learn. Second language learning theory proposes that acquisition is possible in second and subsequent languages, and that learning programmes have to create the conditions for it.

The belief that acquisition is possible lies at the heart of any method that involves engaging the learner in natural communication and authentic input.