Language Acquisition Device

Historical Context

Noam Chomsky originally proposed the existence of the (virtual, not physical) LAD in developing his theories of syntax and universal grammar (UG) during the late 1950s and early 1960s. Chomsky was working in response to B. F. Skinner's behavioralist theories of language acquisition, which assumed that language was learned through imitation, habit formation, and reinforcement. In behavioralism, language learning is a process external to the child where the environment provides everything necessary for language acquisition. In contrast to this, Chomsky asserted that humans are biologically endowed with an innate mechanism for learning language, and that the environment provides language as input to the language-learning process. The child, using the LAD, processes that input and gradually acquires adult-like knowledge of a language. This process is largely subconscious and is automatic, much like learning to walk.

Chomsky's use of language refers to the syntax, or structure, of a language, rather than to its functions and social uses. Similarly, grammar is the set of rules for a language that allow any and all sentences in that language to be produced and understood, rather than the traditional prescriptive grammar learned in school (e.g., “ain't” is bad English).

How the LAD Works

The LAD is frequently referred to as an organ, although it resides in and is an inseparable part of the human brain. This reflects a modular understanding of both language learning and the mind, indicating that language learning is different from other types of learning (e.g., learning to add and subtract) and that the LAD is only used for language acquisition. The LAD contains the cognitive tools necessary for learning a language as a child, which include UG, and is the primary means of analyzing language input.