the nativist perspective

the nativist perspective. The nativist perspective, turning to innate
mechanisms for language development, has the following underlying assumptions:
language is a human-species-specific capacity; language is “unlearnable,”
because it is impossible for a naïve and immature child to figure
out such a complex linguistic system from an imperfect, not very consistent,
highly opaque, and frequently ambiguous language environment; and
there is a common structural core in all human languages. In 1965, linguist
Noam Chomsky posited an innate language-acquisition device (LAD), with
the “universal grammar” residing in it, to explain children’s rapid acquisition
of any language and even multiple languages. LAD is assumed to be a
part of the brain, specialized for processing language. Universal grammar is
the innate knowledge of the grammatical system of principles and rules expressing
the essence of all human languages. Its transformational generative
grammar consists of rules to convert the deep structure (grammatical
classes and their relationships) to surface structure (the actual sentences
said) in the case of production, or vice versa in the case of comprehension.

Equipped with this biological endowment, children need only minimal language
exposure to trigger the LAD, and their innate knowledge of the universal
grammar will enable them to extract the rules for the specific language(
s) to which they are exposed.
Evidence for the nativist perspective can be discussed at two levels: the
linguistic level (language rules and structure) and the biological level. At
the linguistic level, people are sensitive to grammatical rules and linguistic
structural elements. For example, sentences in the active voice are processed
more quickly than sentences in the passive voice, because the former
type is closer to the deep structure and needs fewer transformation steps
than the latter type. “Click insertion” studies (which insert a “click” at different
places in a sentence) and “interrupted tape” studies (which interrupt a
tape with recorded messages at different points) have shown a consistent
bias for people to recall the click or interruption position as being at linguistic
constituent boundaries, such as the end of a clause. After a sentence has
been processed, what remains in memory is the meaning or the gist of the
sentence, not its word-for-word surface structure, suggesting the transformation
from the surface structure to the deep structure. Around the world,
the structure of creolized languages (invented languages), including the
sign languages invented by deaf children who have not been exposed to any
language, is similar and resembles early child language. Young children’s
early language data have also rendered support. In phonology, habituation
studies show that newborns can distinguish between phonemes such as /p/
and /b/. Most amazingly, they perceive variations of a sound as the same if
they come from the same phoneme but different if they cross the boundary
into a different phoneme (categorical speech perception). In semantics, babies
seem to know that object labels refer to whole objects and that a new
word must mean the name of a new object. If the new word is related to an
old object whose name the child already knows, the word must mean either
a part or a property of that object (the mutual exclusivity hypothesis). In the
domain of grammar, Dan Isaac Slobin’s 1985 cross-cultural data have shown
that young children pay particular attention to the ends of words and use
subject-object word order, probably as a function of their innate operating
principles. By semantic bootstrapping, young children know that object
names are nouns and that action words are verbs. By syntactic bootstrapping,
they understand a word’s grammatical class membership according to
its position in a sentence. Even young children’s mistaken overregularization
of grammatical rules to exceptions demonstrates their success in rule
extraction, as such mistaken behavior is not modeled by adults.