Chimpanzees have been taught some limited sign language, but their use of it is essentially limited to simple requests for food or other basics. Having worked to teach chimps simple nonverbal communication, Dr. David Premack concluded: “Human language is an embarrassment for evolutionary theory because it is vastly more powerful than one can account for.”

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Language and Intelligence

Why does human intelligence far surpass that of animals, such as apes? A key is our use of syntax—putting sounds together to make words and using words to make sentences. Theoretical neurophysiologist Dr. William H. Calvin explains:

“Wild chimpanzees use about three dozen different vocalizations to convey about three dozen different meanings. They may repeat a sound to intensify its meaning, but they do not string together three sounds to add a new word to their vocabulary.

“We humans also use about three dozen vocalizations, called phonemes. Yet only their combinations have content: we string together meaningless sounds to make meaningful words.” Dr. Calvin noted that “no one has yet explained” the leap from the animals’ “one sound/one meaning” to our uniquely human capacity to use syntax.