Translating the 'sign language' of CHIMPS: Experts discover meaning of 66 gestures used to ask for sex, offer help and discipline
- Researchers from Scotland studied chimps in Budongo Forest in Uganda
- They examined 4,531 gestures within 3,419 examples of communication
- This was used to identify 66 gestures for 19 specific message meanings
- Mothers presenting their foot shows a child they can climb on their back
- While nibbling on a leaf signals intent that a chimp is available to mate
- In a second study, researchers from Switzerland studied bonobo gestures
- They identified the human-like sweeping gesture used to initiate sex
- This includes stretching an arm towards a mate, sweeping it inwards, then finishing with a wrist-twirl that turns a downward-facing palm upwards
Monkeys and apes use loud calls and gestures to make their feelings known but until now, the exact meaning for individual movements has remained a mystery.
Now, researchers believe they have translated the key gestures used in the chimp community and deciphered their intentions, for the first time.
From 4,351 gestures, experts were able to identify 66 that are used for 19 specific message meanings – including showing a foot to tell a child they can climb on their back, to nibbling a leaf to signal intent to mate.
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Researchers from Scotland have translated the key gestures used by chimps. From 4,351 gestures, experts were able to identify 66 that were used for 19 specific message meanings, including hugging the air to ask for an embrace (stock image pictured), and slapping objects together to ask another chimp to follow them
The researchers were able to narrow down these 66 gestures to 36 that are used intentionally to achieve 15 purposes, other than in play.
The translations were made by Dr Catherine Hobaiter and her colleagues at St Andrews University in Scotland.
Observations were made on chimpanzees within the Sonso community in the Budongo region of the rainforest, in Uganda.
During three field periods between October 2007 and August 2009, Dr Hobaiter used focal behaviour sampling and filmed all recorded cases of gestural communication using a Sony Handycam.
Other gestures include stomping their feet to ask another chimp to stop what they are doing, and slapping objects together to ask another to follow them.
Of the 19 meanings, 17 encouraged interactions to start, such as ‘groom me’, or to develop, such as ‘move closer,’ and ‘change play’.
Recordings taken from 2007 to 2009 in Uganda found that nibbling on a leaf (stock image pictured) signals intent that a chimp is ready to mate
Some of the gestures were found to have more than one meaning, and only 10 of the 66 gestures were used for only a single meaning, and of these, seven were recorded on three or fewer occasions.
‘We can finally say for the first time that another animal communication has meaning; not just information and not just complicated communication, but meaningful communication,’ Dr Hobaiter told BBC News.
‘[Recent] findings about great ape gestures spurred interest in a potential common ancestral origin with components of human language.
‘Of particular interest, given the relevance to language origins, is the question of what chimpanzees intend their gestures to mean; surprisingly, the matter of what the intentional signals are used to achieve has been largely neglected.
‘Here we present the first systematic study of meaning in chimpanzee gestural communication.’
The research is published in the journal Current Biology.
In a separate study, primatologists Emilie Genty and Klaus Zuberbühler from Switzerland’s University of Neuchâtel wanted to translate a specific gesture used by bonobos.
They discovered that the gesture, which involves stretching an arm towards another bonobo, sweeping it inwards, then finishing with a wrist-twirl that turns a downward-facing palm upwards, is used to initiate sex.
The researchers were able to narrow down these 66 gestures to 36 that are used intentionally to achieve 15 purposes, other than in play. For example, when a mother shows their chimp the bottom of their foot (stock image pictured), it tells the child they are allowed to climb on their parent's back
In a separate study, primatologists from Switzerland's University of Neuchâtel wanted to translate a specific gesture used by bonobos. Stretching an arm towards another bonobo, sweeping it inwards, then finishing with a wrist-twirl that turns a downward-facing palm upwards (pictured) is used to initiate sex
Over 222 hours of observation time, the researchers collected a total of 471 video clips from two social groups of bonobos at a sanctuary near Kinshasa, Democratic Republic of Congo.
They spotted 1,080 sexual solicitations, initiated by 18 males and 17 females.
As well as identifying what the gesture means, they also discovered the technique needed to increase the chances of success.
When the gestures resulted in sex, the initiator approached from a distance of around 3ft (1 metre) with their back in a concave position.
Success also depended on how many other bonobos were present, and if any others were seen as competition.
Over 222 hours of observation time, the researchers collected a total of 471 video clips from two social groups of bonobos in Kinshasa, Democratic Republic of Congo. They spotted 1,080 sexual solicitations, initiated by 18 males and 17 females. This flow chart shows the success to failure rate
‘Human children use gestures to communicate before they produce their first words, and their earliest gestures are deictic and typically emerge around 10 months of age,' explained the researchers.
‘Iconic gestures therefore seem to be cognitively more demanding than deictic gestures or other conventionalized signals.
‘In great apes, there is good evidence that language-trained individuals are capable of acquiring and understanding both deictic and iconic signals, but this is far less clear in their natural communication.
‘Although we cannot claim with confidence that the beckoning gesture is produced with an understanding of its iconic nature, our findings are relevant in that they provide evidence that great apes can naturally use spatial reference as part of a communicative intention, with recipients responding to such signals appropriately.
‘The ability to produce gestures that depict some spatial features of a desired action was therefore probably already present in the common ancestor of humans and apes.’
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