The sometimes angelic appearance of children may suggest innocence and purity, but this is an illusion. Our reaction to the appearance of children is a biological imperative and has nothing to do with good sense, but it does conjure up the idea of a natural or pure version of things. The myth that that there is a pure or natural version of language is very old, with the first reference I know of being in "The Histories" by Herodotus (485 B.C.). I cannot recall the details but it is very similar to the story told to me by my parents about the different dialects spoken in different parts of England. To discover which dialect was the pure or natural version, the king placed two babies onto an uninhabited island. The infants were minded by two mutes whose silence prevented any influence on the dialect chosen by their charges. Free from contamination the pure version of language adopted by the children turned out to be that spoken by the local seagulls.
There is no pure or natural language just as there is no pure or natural behaviour. Infants do not know how to behave but will discover it through upbringing, and centuries of experience have taught humanity the necessity of the cane if the adult is not to become a selfish monster.