The Language Acquisition Device (LAD) is a hypothetic module of the brain posited to account for children's innate predisposition for language acquisition.
First proposed by Noam Chomsky in the 1960s, the LAD concept is an instinctive mental capacity which enables an infant to acquire and produce language. It is component of the nativist theory of language. This theory asserts that humans are born with the instinct or "innate facility" for acquiring language. The main argument in favor of the LAD is the argument from the poverty of the stimulus, which argues that unless children have significant innate knowledge of grammar they would be unable to learn language as quickly as they do, given that they never have access to negative evidence and rarely received direct instruction in their first language. Chomsky has gradually abandoned the idea of a LAD in favour of Universal Grammar and a parameter-setting model of language acquisition (principles and parameters).