THANKS to their large size and humanlike features, gorillas, bonobos, orangutans and chimpanzees are graciously referred to as the ‘Great Apes’. The title is deserved, because these larger primates share far more similarities with humans than their smaller cousins, the monkeys.
Apes, like humans, have an appendix and lack tails and are distinguished by having far more complex brains than monkeys. That latter attribute allows Great Apes to recognise themselves in mirrors and we have seen evidence of apes being capable of abstract reasoning as well; in a 2013 study, five apes were shown pictures of animals from different species on a touchscreen to see if they could match those belonging to the same species, with the apes getting a reward snack if they got it right. All of the apes were able to match turtles with snakes (both are reptiles) even though there is very little visual resemblance between the two.
Great Apes have also shown an ability to work with simple tools, and chimpanzees, as famous primatologist Jane Goodall discovered, even make simple tools by stripping twigs of their leaves and using them to ‘fish’ for ants or bees. In the wild, both bonobos and chimpanzees have also been seen making ‘sponges’ out of porous moss and leaves and using these to groom themselves.
Given that complex brains are a requirement for developing speech, or even quasi-linguistic communication, a lot of scientific interest has been devoted to seeing if apes use, or are capable of learning communication through verbal or non-verbal language.
The phenomenon of apes learning sign language isn’t new.
Here the case of the famous gorilla Koko comes to mind who was successfully taught sign language, although there is some controversy as to whether she possessed a working vocabulary of over 1,000 sign language words as her trainer claimed.
Regardless, the phenomenon of apes learning sign language isn’t new, as the first chimpanzee to be successfully taught sign language was a female named Washoe in 1966. Amazingly, Washoe didn’t just learn sign language, she was also capable of teaching it to other chimps, as she did with a 10-month-old chimp named Loulis who was given into her care. Washoe taught her young student by not just demonstrating the signs, but also moulding the young chimp’s hands to teach him the correct signs.
But what about in the wild? In 2014, Dr Catherine Hobaiter and her team filmed communities of chimps in Uganda and recorded the use of language through stances, signs and gestures, sometimes accompanied by vocalisations. Noting that specific gestures and signs were repeated across communities of chimps, the team found a ‘vocabulary’ of at least 66 gestures that were meant to communicate specific messages, like ‘climb on my back’ and even ‘flirt with me’. At the time, this was claimed to be the “only form of intentional communication to be recorded in the animal kingdom”.
While Hobaiter’s team identified 19 specific messages, a few years later, another team expanded this by noting “approximately 2,000 examples of 58 unique gestures used by the chimps when communicating with one another”, and also found that the linguistic rules governing these communications gestures were the same as the linguistic rules for human language, which are similar regardless of which language is being used. For example, words that are used frequently tend to be shorter, whether the language in question is Urdu or Chinese … or ‘Chimpanzee’.
But up until now, the consensus was that humans were still the only species to use spoken language which, without any other non-verbal aids or cues, could be understood as a specific message. After all, while animals do use ‘calls’ to signify danger, as warnings, or as indications of a willingness to mate, they do not — as was believed — combine such calls to form actual vocal sequences the way humans combine a small number of sounds (there are typically less than 50 sounds in any given human language) to form complex words and sentences.
Until now, that is. Earlier this year, researchers at the Max Planck institute in Leipzig and the Institute of Cognitive Sciences in France teamed up to record thousands of vocalisations by three different groups of chimpanzees in Ivory Coast and found something truly remarkable: chimpanzees in the wild actually combine up to 12 different call types to form hundreds of different sequences, which are capable of conveying complex messages. In essence, this is the first verified research that points to the existence of an actual spoken language for chimpanzees and the next step now is to determine what these sequences mean in terms of the concepts they mean to convey. That research, then, would provide invaluable insight into how human languages developed and, given the effect that language proficiency has on our cognitive abilities, would likely result in a better understanding of how our own brains work.
The writer is a journalist.
Published in Dawn, January 2nd, 2023