Tourette's Syndrome

I've met a little pre-school boy with Tourette's Syndrome. There are episodes of terrible language; this is one of the major symptoms. Where does the vocabulary come from?

I know for a fact that his parents do not use this type of language. He is not in school yet. They do not have a TV.

Logically, he heard it Somewhere.... (after all, he is not cursing in Chinese or Urdu)