As before, when linguists actually went looking at the variation in languages across the world, they found counterexamples to the claim that this type of recursion was an essential property of language. Some languages — the Amazonian Pirahã, for instance — seem to get by without Chomskyan recursion.
As with all linguistic theories, Chomsky’s universal grammar tries to perform a balancing act. The theory has to be simple enough to be worth having. That is, it must predict some things that are not in the theory itself (otherwise it is just a list of facts). But neither can the theory be so simple that it cannot explain things it should. Take Chomsky’s idea that sentences in all the world’s languages have a “subject.” The problem is the concept of a subject is more like a “family resemblance” of features than a neat category. About 30 different grammatical features define the characteristics of a subject. Any one language will have only a subset of these features — and the subsets often do not overlap with those of other languages.
Chomsky tried to define the components of the essential tool kit of language — the kinds of mental machinery that allow human language to happen. Where counterexamples have been found, some Chomsky defenders have responded that just because a language lacks a certain tool — recursion, for example — does not mean that it is not in the tool kit. In the same way, just because a culture lacks salt to season food does not mean salty is not in its basic taste repertoire. Unfortunately, this line of reasoning makes Chomsky’s proposals difficult to test in practice, and in places they verge on the unfalsifiable.
A key flaw in Chomsky’s theories is that when applied to language learning, they stipulate that young children come equipped with the capacity to form sentences using abstract grammatical rules. (The precise ones depend on which version of the theory is invoked.) Yet much research now shows that language acquisition does not take place this way. Rather young children begin by learning simple grammatical patterns; then, gradually, they intuit the rules behind them bit by bit.
Thus, young children initially speak with only concrete and simple grammatical constructions based on specific patterns of words: “Where’s the X?”; “I wanna X”; “More X”; “It’s an X”; “I’m X-ing it”; “Put X here”; “Mommy’s X-ing it”; “Let’s X it”; “Throw X”; “X gone”; “Mommy X”; “I Xed it”; “Sit on the X”; “Open X”; “X here”; “There’s an X”; “X broken.” Later, children combine these early patterns into more complex ones, such as “Where’s the X that Mommy Xed?”
Many proponents of universal grammar accept this characterization of children’s early grammatical development. But then they assume that when more complex constructions emerge, this new stage reflects the maturing of a cognitive capacity that uses universal grammar and its abstract grammatical categories and principles.
For example, most universal grammar approaches postulate that a child forms a question by following a set of rules based on grammatical categories such as “What (object) did (auxiliary) you (subject) lose (verb)?” Answer: “I (subject) lost (verb) something (object).” If this postulate is correct, then at a given developmental period children should make similar errors across all wh-question sentences alike. But children’s errors do not fit this prediction. Many of them early in development make errors such as “Why he can’t come?” but at the same time as they make this error — failing to put the “can’t” before the “he” — they correctly form other questions with other “wh-words” and auxiliary verbs, such as the sentence “What does he want?”
