How did Noam Chomsky's ideas change theories about language acquisition?

Noam Chomsky revolutionized the study of language acquisition by challenging the prevailing behaviourist view that language is merely a learned response to environmental stimuli. Instead, he proposed that language is a uniquely human, biologically based cognitive capacity.12

Key aspects of his influence include:

• Innate Knowledge: Chomsky argued that children are born with an innate knowledge of formal grammatical principles, often referred to as universal grammar. This explains how children can acquire language with remarkable speed and facility despite the "poverty of the stimulus"—the lack of sufficient instruction or meaningful evidence in their early environment.34
• Mental Processes: By refuting behaviourist models, such as those proposed by B.F. Skinner, Chomsky shifted the focus of linguistics toward internal mental processes. He posited that language learning involves the unconscious construction of a grammar based on innate principles, rather than simple conditioning.15
• Creative Use: Chomsky emphasized that language use is "creative" rather than causal; speakers can produce and understand an infinite number of novel sentences they have never heard before, enabled by these underlying mental systems.14

His work helped initiate the "cognitive revolution," reorienting linguistics toward the study of the human mind.25