Language seems to be somewhat directed by innate structures built into the human
brain. Humans are the only animals to produce a complex, grammatical language
that represents things both concrete (such as "chair") and abstract (such as
"loyalty"). A debate rages in the literature on this subject over whether our
ability stems from some biological basis for language or from our generally
superior cognitive abilities. Currently, the debate seems to have reached the
consensus that, at birth, the brain does not information specific to a
particular language, like the meanings of words or particular grammatical rules,
but it is "wired" in a general way to make it comparatively easy for a child to
learn any language. Evidence for a biological basis for language comes from
several sources.
Anatomical studies of the brain show that it contains certain areas that are
devoted to processing and producing language.
Broca's area controls the
production of speech and the meanings of words, while
Wernicke's area controls
the perception of speech and the rules of grammar. Damage to these areas can
cause deficits in linguistic abilities known as
aphasias. In addition,
brain imaging studies show that these areas tend to be
active when people
perform language-related tasks. These areas are discussed more in the section
on
language in the
Neuropsychology SparkNote.
Other evidence for a biological basis for language stems from the universality
of language. If all humans, regardless of geographical location or cultural
background, share a particular trait, we usually infer that the trait must have
some basis in the biological genes that humans share. Most human languages are
remarkably similar, despite their sometimes extraordinary separation over time
and space. Rules that apply over a wide range of languages, such as those
concerning the phrase structure of sentences and the possibility of
contractions in different linguistic situations, are known as linguistic
universals. For example, the subject of a sentence precedes the object in 98
percent of the world's languages; this rule, then, is a linguistic universal.
Other
linguistic universals deal with the internal logic of languages (e.g. if
phrase structure is A, then form of question is B) rather than explicit rules
for phrase structure or word order. The existence of a fair number of
linguistic universals supports the theory of a biological basis for language.
Children's patterns of language learning also signal some innate biological
prompting. Children learning many different languages follow the same patterns
in learning
irregular nouns and verbs; first they memorize, then they
overgeneralize. They also tend to go through these stages at approximately
the same ages. The fact that children learn language in the same fashion across
cultures suggests that there is a biological blueprint already in place that
guides them in their learning. Also, children tend to learn language best
before the age of six or seven, and becoming truly fluent in a language after
age twelve is nearly impossible. This linguistic window of opportunity suggests
an analogous biological window that disappears as the brain matures. Overall,
the compounded evidence makes a strong case for some biological component to
language.
