It is enough to say that, well before school age,
normal children develop a well-formed system of language. The ease with
which language is developed, in the absence of direct instruction, and in
circumstances in which uniformity of support and reinforcement (especially
from parents) cannot be assumed, has been a continuing source of inspiration
for linguists and others for a very long time. It has, in fact, prompted a
revival of Cartesian rationalism in linguistics, which explains the rapidity
and the complexity of language learning through brain readiness or "pre wiring