Do this, Vicky.

Another sound resembles the letter K.

Vicky, sit up.

Not even our closest relatives, the chimps, can talk.

Psychologists spent nearly seven years trying to teach Vicky to speak with little success.

And in this case they really tried to teach a chimp to say some basic words and completely failed, and everyone knew of course that,

Parrots can learn to imitate speech.

So it was kind of a very surprising and eye-opening experience to see that these chimps with great big brains for an animal were not able to do this.

It was already very clear that Chimpanzees don't have the kind of control over their vocal tract that we do.

So once people knew that chimpanzees couldn't produce speech, the big question was why?