Researchers Decode Chimpanzee Sign Language

Researchers at University of St Andrews have created a "dictionary" of gestures used by chimpanzees. The study explains what wild chimps are saying to each other when they use a certain hand or body movement.

Primatologists had known that primates use signs to communicate, but nobody and conducted a scientific study to understand what these gestures meant.

"There is abundant evidence that chimpanzees and other apes gesture with purpose. Apes target their gestures to particular individuals, choosing appropriate gestures according to whether the other is looking or not; they stop gesturing when they get the result they want; and otherwise they keep going, trying out alternative gestures or other tactics altogether," said Professor Richard Byrne, primatologist at the University of St Andrews, one of the study authors.

The study was based on observation of 80 wild chimpanzees in the rainforest of Uganda. The team videotaped chimpanzee movements in the Budongo Forest and analyzed 4500 instances of gesturing.

Researchers first had to sort non-playtime gestures from playtime signs because during play, chimps often use signs with no "real meaning."

In all, the team found 66 consistent gestures, which is used by the primates to "talk" to each other. These gestures can be used in isolation or in combination to make complex commands, abc news reported.

Here are some of the gestures and meanings;

• When a chimpanzee taps another, it means "stop that"
• Slapping an object means "move away"
• Raised arm means 'I want that' or 'give me that."
• Mother showing sole of her foot to her baby indicates that she wants the baby to climb on her
• Chewing leaves is a call for sexual attention
• Touching arm means "scratch me."

"Just as with human words, some gestures have several senses, but importantly the meanings of chimpanzee gestures are the same irrespective of who uses them. Chimpanzees may use more than one gesture for the same purpose - especially in social negotiations, where the final outcome may be a matter of some give and take," Dr Catherine Hobaiter, primatologist from University of St Andrews, one of the study authors.

Now that the team has the basic dictionary of chimpanzee language, they plan on studying the possible variations of these gestures to get a better understanding of chimpanzee communication.

The study is published in the journal Current Biology.