Researchers at St. Andrews University have deciphered the meanings of chimpanzee's gestures like arm raises, ground slaps and foot stomps.

It has been long known that wild chimpanzees use gestures to communicate. But until now scientists haven't yet been able to reveal their meaning.       

"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," primatologists Professor Richard Byrne said in a statement.

For the study, the researchers closely observed the behaviour of 80 wild chimps in the Budongo Forest, Uganda. Using videos, they recorded communicative interactions and extracted over 4500 cases of gesturing. Among these, researchers successfully decoded the meanings of 66 gestures.

For example, when a chimpanzee taps another it means 'stop that'; a hand fling or slapping an object means 'move away'; while an arm raise means 'I want that' or 'give me that'.

"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," primatologists Dr Catherine Hobaiter said.            

The study titled, "The meanings of chimpanzee gestures" is published in the journal Current Biology.