In the mid-sixties, the field [acquisition study], which had previously been atheoretical and somewhat underdeveloped, came to be dominated by a type of innatist theory. This theory, derived largely from generative grammar, and in particular from works such as Chomsky [Chomsky, N. 1962. “Explanatory models in Linguistics”, in Nagel, E. et alii Logic, Methodology and the Philosophy of Science, Stanford, Stanford University Press] held that the child acquired language through simple exposure to linguistic data, much of which was “degenerate”- i.e., consisted of sentence fragments, mid-sentence reformulations, and many types of performance error which would render natural speech a very unreliable mirror to mature native-speaker competence. Somehow the child had to sift the wheat from the chaff, and he could only do this, it was claimed, if he had some kind of inbuilt Language Acquisition Device (LAD).
- Bickerton (1981), Pag. 136