How did Noam Chomsky challenge behaviorist explanations of language learning?

Noam Chomsky challenged behaviorist explanations of language learning by rejecting the idea that the human mind is a tabula rasa (blank slate) at birth. While behaviorists like B.F. Skinner viewed language acquisition as a conditioned response to external stimuli, Chomsky argued that language use is essentially creative and uncaused by specific environmental triggers.1

His critique, most notably his 1959 review of Skinner’s Verbal Behavior, posited that children acquire language with a speed and facility that cannot be explained by instruction or reinforcement alone. This observation led to the argument from the "poverty of the stimulus," which suggests that because children receive insufficient linguistic input to account for their complex grammatical knowledge, they must possess an innate Universal Grammar (UG).123

Rather than learning through taxonomic classification of data, Chomsky proposed that children unconsciously construct a grammar by setting "parameters" within the constraints of innate linguistic principles. Thus, he shifted the study of language from a focus on external behavior to the discovery of the internal, biological systems that enable human linguistic creativity.312