Chimpanzees, the closest living relatives of humans, have their own way of communication, which includes various gestures. A team of scientists has claimed in a new study that they have for the first time successfully decoded what these apes are attempting to say through different movements of their bodies, hands and feet.
As part of the study, published in the journal Current Biology, the researchers observed more than 80 wild chimpanzees and developed a dictionary of meanings behind a variety of gestures by chimpanzees, such as arm raises, ground slaps and foot stomps. According to the researchers, the findings of the study lend further credibility to the long-held belief that chimps have a purpose when they communicate with each other.
“There is abundant evidence that chimpanzees and other apes gesture with purpose,” Richard Byrne, a primatologist at the University of St. Andrews in the U.K., said in a statement. “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.”
Scientists chose the Budongo Forest in Uganda to study the behavior of chimpanzees. They recorded video footage of communicative interactions among chimpanzees and extracted more than 4,500 instances of gesturing. The scientists focused on gestures when the chimps were not in a playful mood -- because, in play, gestures may not be used to convey their actual meanings -- and they identified 19 specific meanings of 66 gestures.
When one chimpanzee taps another, it means, “Stop that.” While a hand fling or slapping an object means, “Move away,” an arm raise means, “I want that” or “Give me that,” according to the researchers.
“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,” said Catherine Hobaiter, also a primatologist at the University of St. Andrews and the lead author of the study. “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.”
According to the researchers, the next step for them is to determine whether the chimpanzees use any variations while making gestures to express subtle changes in the meaning. “The vagueness of the gesture meanings suggest either that the chimps have little to communicate, or we are still missing a lot of the information contained in their gestures and actions,” Hobaiter told BBC News.