Chomsky's Language Acquisition Device: Definition & Explanation

Language Acquisition Device

Anybody who has had or known a child knows that children take to learning language at a remarkable rate. In fact, it seemed a little too remarkable for one linguistics researcher.

Noam Chomsky, a pioneering linguist and a professor at MIT, put forth an idea called the language acquisition device or LAD, for short. The LAD is a hypothetical tool hardwired into the brain that helps children rapidly learn and understand language. Chomsky used it to explain just how amazingly children are able to acquire language abilities as well as accounting for the innate understanding of grammar and syntax all children possess.

Keep in mind that the LAD is a theoretical concept. There isn't a section of the brain with 'language acquisition device' printed on it and a big switch to turn on and learn a new language. Rather, the LAD is used to explain what are most likely hundreds or thousands of underlying processes that humans have in their brains that have evolved to make us particularly exceptional at learning and understanding language.

Chomsky developed the LAD in the 1950s, and since then, has moved on to a greater theory called universal grammar (or UG) to account for the rapid language development in humans. While universal grammar is a bit beyond the scope of this article, just remember for now that LAD later evolved into this theory.

How it Works

Let's go into a little more detail on the LAD. Chomsky proposed that every child was born with an LAD that holds the fundamental rules for language. In other words, children are born with an understanding of the rules of language; they simply need to acquire the vocabulary.

Chomsky offered a number of pieces of evidence to support his theory. He posed that language is fundamentally similar across all of humanity. For instance, every language has something that is like a noun and a verb, and every language has the ability to make things positive or negative.

Chomsky also discovered that when children are learning to speak, they don't make the errors you would expect. For instance, children seem to understand that all sentences should have the structure 'subject-verb-object', even before they are able to speak in full sentences. Weird, huh?

From his experiments, Dr. Chomsky also noted that young children, well before reaching language fluency, would notice if adults around them spoke in a grammatically incorrect manner. He also found that children attempt to apply grammatical rules to words for which their language makes an exception. For example, in following the English rules of grammar, a child might pluralize the word 'fish' as 'fishes' and 'deer' as 'deers',even though out language makes exceptions for those words.

Universal Grammar

However, Skinner's account was soon heavily criticized by Noam Chomsky, the world's most famous linguist to date. In the spirit of cognitive revolution in the 1950's, Chomsky argued that children will never acquire the tools needed for processing an infinite number of sentences if the language acquisition mechanism was dependent on language input alone.

Consequently, he proposed the theory of Universal Grammar: an idea of innate, biological grammatical categories, such as a noun category and a verb category that facilitate the entire language development in children and overall language processing in adults.

Universal Grammar is considered to contain all the grammatical information needed to combine these categories, e.g. noun and verb, into phrases. The child’s task is just to learn the words of her language (Ambridge & Lieven). For example, according to the Universal Grammar account, children instinctively know how to combine a noun (e.g. a boy) and a verb (to eat) into a meaningful, correct phrase (A boy eats).

This Chomskian (1965) approach to language acquisition has inspired hundreds of scholars to investigate the nature of these assumed grammatical categories and the research is still ongoing.