I think O'Meara may be onto something. I remember the first time I heard my son sing that taunt. I wondered at the time if was innate (not mention inane), or part of the collective unconscious, because I was pretty sure he had not been exposed to it otherwise. It was before he started pre-school, he had little exposure to other children, and we do not have a TV from which he might have heard it.

I also wonder if the na/nayh part comes in because that is the easiest sound to enunciate with a sneer on one's face. Try it on your spouse and you will see just what I mean! (and so will your spouse)

Janie