About 50 years ago, researchers Beatrix and Alan Gardner taught a young female chimp called Washoe how to sign using American sign language. They raised her like one of their own. They dressed her, played with her, ate at the table with her and took her for rides in the family car. They communicated exclusively with her in sign language and, pretty quickly, Washoe began to sign back.
By the time she was five, she had learned about 350 signs. Her fingers were dextrous and fast, and often she would combine signs together to make new meanings. When she saw a swan for the first time, Washoe made the signs for ‘water’ and ‘bird’.
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Similar projects followed, with mixed results. When chimps were treated less like family, and more like test subjects, they did less well. Chimps, it turns out, need a stable family environment if they are to learn to communicate well – just as we do.
Then the researchers moved on and many of the chimps were rehomed in sanctuaries, where things took a turn for the worse. After spending so much time with their human teachers, the apes found it hard to adjust to living with their own kind. Washoe signed her displeasure. She referred to her new chimp neighbours as ‘black bugs’.
It was an ethically challenged time for chimpanzee research. While the experiments showed that chimps are smart and can grasp some of the basics of human language, it was all desperately artificial.
Studying chimp language in the wild
So, researchers moved on to studying how the animals communicate naturally in the wild. Primatologist Cat Hobaiter, from the University of St Andrews, has been studying communication in chimps for more than 15 years, predominantly in Uganda. Chimps communicate with each other vocally, via hoots, grunts and other sounds, but they also communicate with gestures.
“From a young alpha male to a 60-year-old grandma, these animals are gesturing all day, every day,” says Hobaiter. “There’s a constant back and forth between individuals. It’s how they run their lives.”
By watching the chimps carefully, and studying the responses that specific gestures elicit, Hobaiter has been able to work out what many of them mean. An arm extended with an upturned palm means ‘give me that’. A shoeing away gesture means ‘back off’. A long slow scratch, meanwhile, can have different meanings depending on the context. It can mean ‘groom me’ or ‘I’ll groom you’, but it can also mean ‘let’s travel’.
The Great Ape Dictionary
To date, Hobaiter has discerned about 150 different gestures, made with the animals’ hands and bodies, that she has catalogued as part of a project called The Great Ape Dictionary. Most of these gestures are common to other apes, such as bonobos and gorillas, and within chimps, there are regional differences – the chimp equivalent of having different dialects or accents.
A far cry from the human-determined signs that chimps were taught in lab experiments, chimp gesture has evolved in the wild to convey the sorts of things that are meaningful and important to them.
And it turns out that what we tend to do with language, they tend to do with gesture, and vice versa. Humans, for example, use speech to make arrangements and body language to add emphasis. Chimps are more likely to gesture ‘come here’ and ‘give me that’, but vocalise to convey emphasis or tone. Screams can be used to indicate alarm, while ‘pant hoots’ (a series of ‘hoos’ and pants that build into a scream) tend to be a sign of excitement.
Indeed, chimp gesture is the closest thing that these primates – and perhaps any non-human animal – have to language. They do ‘talk’ with their hands, all the time. It’s not language but it does contain units of information that have meaning, and that are communicated deliberately to other animals with intent.
Chimp gesture is a system that is full of richness and subtleties that we are only just beginning to understand. For chimps, it’s about as perfect a communication system as you can get.
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Main image credit: Getty
