Lab chimp speaks his own language
An Animal Rights Article from All-Creatures.org

FROM

NewScientist.com
January 2003

A bonobo has surprised his trainers by appearing to make up his own "words".

It is the first report of an ape making sounds that seem to hold their meaning across different situations, and the latest challenge to the orthodox view that animals do not have language.

Kanzi is an adult bonobo kept at Georgia State University in Atlanta. He has grown up in captivity among humans, and is adept at communicating with symbols. He also understands some spoken English, and can respond to phrases such as "go out of the cage" and "do you want a banana?"

Jared Taglialatela, Sue Savage-Rumbaugh and Lauren Baker, who work with Kanzi, noticed that he was making gentle noises during his interactions with them. "We wanted to know if there was any rhyme or reason to when they were produced," says Taglialatela.

So his team studied 100 hours of videotape showing Kanzi's day-to-day interactions and analysed the sounds he made at various times. They picked situations in which the bonobo's actions were unambiguous: for example, while he was eating a banana, pointing to the symbol for "grapes", or responding to a request to go outside by leaving the cage.

They identified four sounds that Kanzi made in different contexts - banana, grapes, juice and yes. In each of these contexts, Kanzi made the same sound. "We haven't taught him this," says Taglialatela. "He's doing it on his own."

Emotional state

Some will argue that the sounds are simply the result of differences in Kanzi's emotional state. Taglialatela concedes that emotions may play a part, but says they are not the whole story. For instance, Kanzi's sound for "yes" stayed the same across very different emotional states.

Primatologist Frans de Waal of Emory University in Atlanta, Georgia, agrees. "That emotion is involved doesn't rule out at all that he's following rules that have some sort of cognitive component," he says.

Kanzi is just the latest primate to challenge the view that animals have no language ability. Language used to be popularly defined as symbolic communication until Washoe, a chimpanzee, stumped everyone by learning to communicate in American Sign Language.

"The linguists then came up with a definition that emphasised syntax much more than symbols," says de Waal. "Sometimes we feel it's a bit unfair that they move the goal posts as soon as we get near."

High, medium or low

Recently researchers studying Campbell's and Diana monkeys in the Ivory Coast in West Africa found some evidence of syntax in the calls the monkeys made. And Karen Hallberg and Sally Boysen of Ohio State University in Columbus have noticed hints that when chimps see food, they make calls that specify its desirability as high, medium or low, and that other chimps can interpret the sounds.

But Kanzi comes closest yet to providing concrete evidence that apes can make sounds that carry a particular meaning. "Kanzi is modifying his sounds to denote certain things in his environment," says de Waal. "That's very special."

The results are significant and exciting, agrees primatologist John Mitani of the University of Michigan in Ann Arbor. "Despite the fact that we have had glimmerings of this in the monkey world, few instances of anything like this have been documented among our closest living relatives, chimps and bonobos," he says.

Flexible and applicable

Taglialatela's team has now started studying seven more bonobos in their lab, some of which have not been language-trained. They are also analysing Kanzi's sounds to see if he is actually trying to imitate human speech.

Until more results are in, Mitani and de Waal caution against drawing any firm conclusions. For Kanzi's ability to be considered similar to language, it must be flexible and applicable to many different situations, they say. And Hallberg says she will not consider Kanzi's sounds to be communication until other bonobos are shown to respond to them appropriately.

Nevertheless, the observations add to the growing body of evidence that language skills did not just show up suddenly in humans, and hint that non-human primates may have abilities that could be described as primitive language.

"There have to be evolutionary precursors to what we do," says Mitani. "We are beginning to find them in the primate world."

Journal reference: International Journal of Primatology (vol 24, p 1)


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