Nativist theories

Nativist theories hold that children are born with an innate propensity for language acquisition, and that this ability makes the task of learning a first language easier than it would otherwise be. These "hidden assumptions" [2] allow children to quickly figure out what is and isn't possible in the grammar of their native language, and allow them to master that grammar by the age of three. [3] Nativists view language as a fundamental part of the human genome, as the trait that makes humans human, and its acquisition as a natural part of maturation, no different from dolphins learning to swim or songbirds learning to sing.

Chomsky originally theorized that children were born with a hard-wired language acquisition device (LAD) in their brains [1]. He later expanded this idea into that of Universal Grammar, a set of innate principles and adjustable parameters that are common to all human languages. According to Chomsky, the presence of Universal Grammar in the brains of children allow them to deduce the structure of their native languages from "mere exposure".

Much of the evidence supporting the nativist position is based on the early age at which children show competency in their native grammars, as well as the ways in which they do (and do not) make errors. Infants are born able to distinguish between phonemes in minimal pairs, distinguishing between bah and pah, for example.[4] Young children (under the age of three) do not speak in fully formed sentences, instead saying things like 'want cookie' or 'my coat.' They do not, however, say things like 'want my' or 'I cookie,' statements that would break the syntactic structure of the Phrase, a component of universal grammar.[5] Children also seem remarkably immune from error correction by adults, which Nativists say would not be the case if children were learning from their parents.[6]

* Child: My teacher holded the baby rabbits and we pat them.
* Adult: Did you say your teacher held the baby rabbits?
* Child: Yes.
* Adult: What did you say she did?
* Child: She holded the baby rabbits and we pat them.
* Adult: Did you say she held them tightly?
* Child: No, she holded them loosely.[7]

The possible existence of a Critical Period for language acquisition is another Nativist argument. Critical periods are time frames during which environmental exposure is needed to stimulate an innate trait. Young chaffinches, for example, must hear the song of an adult chaffinch before reaching maturity, or else would never be able to sing. Nativists argue that if a Critical Period for language acquisiton exists (see below), then language acquistion must be spurred on by the unfolding of the genome during maturation.[8]

More evidence of the innateness of language comes from the deaf population of Nicaragua. Until approximately 1986, Nicaragua had neither education nor a formalized sign language for the deaf. As Nicaraguans attempted to rectify the situation, they discovered that children past a certain age had difficulty learning any language. Additionally, the adults observed that the younger children were using gestures unknown to them to communicate with each other. They invited Judy Kegl, an American linguist from MIT, to help unravel this mystery. Kegl discovered that these children had developed their own, distinct, Nicaraguan Sign Language with its own rules of "sign-phonology" and syntax. She also discovered some 300 adults who, despite being raised in otherwise healthy environments, had never acquired language, and turned out to be incapable of learning language in any meaningful sense. While it was possible to teach vocabulary, these individuals were unable to learn syntax.[9]

Derek Bickerton's (1981) landmark work with Hawaiian pidgin speakers studied immigrant populations where first-generation parents spoke highly-ungrammatical "pidgin English". Their children, Bickerton found, grew up speaking a grammatically rich language -- neither English nor the syntax-less pidgin of their parents. Furthermore, the language exhibited many of the underlying grammatical features of many other natural languages. The language became "creolized," and is known as Hawaii Creole English. This was taken as powerful evidence for children's innate grammar module.

Debate within the nativist position now revolves around how language evolved. Derek Bickerton suggests a single mutation, a "big bang," linked together previously evolved traits into full language.[10] Others like Stephen Pinker argue for a slower evolution over longer periods of time.[11]


Non-nativist theories include the competition model and social interactionism. Social-interactionists, like Snow, theorize that adults play an important part in children's language acquisition. However, some researchers claim that the empirical data on which theories of social interactionism are based have often been over-representative of middle class American and European parent-child interactions. Various anthropological studies of other human cultures, as well as anecdotal evidence from western families, suggests rather that many, if not the majority, of the world's children are not spoken to in a manner akin to traditional language lessons, but nevertheless grow up to be fully fluent language users. Many researchers now take this into account in their analyses. Furthermore, as any parent knows, children often pay scarce attention to what they are told to say, instead sticking to their own ungrammatical preferences.

Nevertheless, Snow's criticisms might be powerful against Chomsky's argument, if the argument from the poverty of stimulus were indeed an argument about degenerate stimulus, but it is not. The argument from the poverty of stimulus is that there are principles of grammar that cannot be learned on the basis of positive input alone, however complete and grammatical that evidence is. This argument is not vulnerable to objection based on evidence from interaction studies such as Snow's.

However, an argument against Chomskian views of language acquisition lies in Chomskian theory itself. The theory has several hypothetical constructs, such as movement, empty categories, complex underlying structures, and strict binary branching, that cannot possibly be acquired from any amount of input. Since the theory is, in essence, unlearnably complex, then it must be innate. A different theory of language, however, may yield different conclusions. Examples of alternative theories that do not utilize movement and empty categories are Head-driven phrase structure grammar, Lexical functional grammar, and several varieties of Construction Grammar. While all theories of language acquisition posit some degree of innateness, a less convoluted theory might involve less innate structure and more learning. Under such a theory of grammar, the input, combined with both general and language-specific learning capacities, might be sufficient for acquisition.