In a dome-shaped outdoor cage, a dozen chimpanzees are hooting. The hair on their shoulders sticks straight up. “That’s piloerection,” a sign of emotional arousal, says Dr. Dana Hasselschwert, head of veterinary sciences at the New Iberia Research Center. She tells a visitor to keep his distance. The chimps tend to throw pebbles — or worse — when they get excited.
When the DNA sequences of Homo sapiens and Pan troglodytes were sequenced, the difference between the sequences of coding genes was smaller than expected based on the phenotypic differences between both species. If not the coding genes, then what is responsible for these dissimilarities?
A 25-year-old chimpanzee named “Panzee” has just demonstrated that speech perception is not a uniquely human trait.
Well-educated Panzee understands more than 130 English language words and even recognizes words in sine-wave form, a type of synthetic speech that reduces language to three whistle-like tones. This shows that she isn’t just responding to a particular person’s voice or emotions, but instead she is processing and perceiving speech as humans do.
