The acquisition of language is a universal feat and it is believed we are all born with an innate structure initially proposed by Chomsky in the 1960s. The Language Acquisition Device (LAD) was presented as an innate structure in humans which enabled language learning. Individuals are thought to be "wired" with universal grammar rules enabling them to understand and evaluate complex syntactic structures. Proponents of the LAD often quote the argument of the poverty of negative stimulus, suggesting that children rely on the LAD to develop their knowledge of a language despite not being exposed to a rich linguistic environment. Later, Chomsky exchanged this notion instead for that of Universal Grammar, providing evidence for a biological basis of language.