Dr Catherine Hobaiter and Professor Richard Byrne created a ‘dictionary’ of meanings behind chimp gestures such as arm raises, ground slaps and foot stomps by observing over 80 wild Ugandan chimpanzees.
The results have just been published in the journal Current Biology. Although it has been known for some time that apes use gestures to communicate, it wasn’t until now that we have worked out what they are actually trying to say.
Professor Byrne, explained:
“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.’
In a significant first step towards answering this question, the researchers studied the behaviour of chimpanzees in the Budongo Forest, Uganda. They used video to record communicative interactions, and extracted over 4500 instances of gesturing. They looked specifically at non-playful uses (because in play, gestures may not be used with their ‘real’ meaning) and identified specific meanings for most of the chimpanzee repertoire of 66 gestures.
Amongst the meanings discovered, they found that 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’.
Dr Hobaiter explained:
“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”.
The next steps will involve the St Andrews researchers investigating possible variations in meaning behind certain chimpanzee gestures.
Dr Hobaiter added, “Now that the basic chimpanzee gesture ‘dictionary’ is known, we can start to tackle other interesting questions. Do some gestures have very general meanings, where their intended sense is understood from the context? Or do subtle variations in how a gesture is made determine which sense was meant?”
Our question at Living Links is will someone try and match this type of study for our capuchins? We do see a variety of gestures from our monkeys that are linked with social responses from the rest of the group, any SPRG members up for this challenge?
The paper, ‘The meanings of chimpanzee gestures’ is published by Current Biology on Thursday July 3. The paper is available online at: http://dx.doi.org/10.1016/j.cub.2014.05.066