I have a friend who has never spoken to his child - he is deaf and uses ASL. His son, who is hearing, uses sign language as spontaneously to Dan as he does spoken English to his mother. In fact he used it earlier since the hand coordination required to sign usually developes earlier than the mouth/throat coordination needed to speak.
You might as well say that flight only includes using feathers so jets and bats are merely imitating flight.
You state that "Monkeys, however, have been around people who speak "directly to" them, but they don't talk back. Never. They don't even Sign back to people who are deaf who use Sign to communicate with each other. Never."
You are quite right, monkeys don't, Several Chimpanzees and a couple of apes do however sign back to humans. In fact Koko has been known to lie, claiming when asked that one of the keepers broke a sink that she had broken.
You might want to check the latest research before accusing others of unsubstantiated statements.
edited to point out that some chimps sign not sing!
Last edited by Zed; 07/04/07 12:05 AM.