Language acquisition: Encyclopedia II - Language acquisition - Additional arguments for nativism

Language acquisition - Additional arguments for nativism

However, there exists emerging evidence of both innateness of language and the "Critical Period Hypothesis" 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 seem to be unable to learn syntax.

The developmental period of most efficient language learning coincides with the time of rapid post-natal brain growth and plasticity in both humans and chimps. Prolonged post-natal brain growth in humans allows for an extended period of the type of brain plasticity characteristic of juvenile primates and an extended time window for language learning. The neotenic pattern of human brain development is associated with persistence of considerable language learning capacity into human adulthood.

Derek Bickerton's (1981) landmark work with Hawaiian pidgin speakers studied immigrant populations where first-generation parents spoke highly-ungrammatical "pidgin English". Their children, it was found, grew up speaking a grammatically rich language -- neither English nor the broken 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.

Adapted from the Wikipedia article "Additional arguments for nativism", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki