Resurrecting an old thread - I never verified it, but I've been told of another language invariant:
Think of the baby-talk phrase "All gone!" generally uttered in a high-pitched sing-song voice that starts high on "All" and drops a fifth or a sixth or so to "gone."
The equivalent in French, allegedly, sounds like the English "Ya poo !" (pardon my accent) which is the babyfication of "Il n'y a plus," meaning "There isn't any more." The intonation, the music under the words, is identical.
Any French speakers watching, to confirm or refute?
The reason why "mama" and "papa" are so similar in so many unrelated languages is because those are the earliest sounds children make, and the parents think the child is talking about them.
That, when pronounced like a very young child, does indeed sound like "Ya poo". I don't know if this similar intonation is anything other than an accident, though.
Build a man a fire and he's warm for a day. Set a man on fire and he's warm for the rest of his life.