Even though children under the age of two can’t speak, or at least not very well, they are surprisingly communicative. There’s lots of crying, grunting, pointing, waving and noodle tossing. But George Dvorsky at Gizmodo reports toddlers' behaviors aren’t unique or completely random. It turns out human children share a huge number of gestures with juvenile and adult great apes.
Scientists already knew that great apes, including chimps, bonobos, gorillas and orangutans, all have a complex communication system of over 80 gestures, recently catalogued in The Great Ape Dictionary. Humans are a species of great ape as well, so for a new study published in the journal Animal Cognition researchers decided to watch human children between the ages of 12 and 24 months using the same methods used to observe chimpanzees in their native habitat. The investigators watched 13 children, six in Germany and seven in Uganda, interacting with family, friends and caretakers at home and in daycare, recording their gestures. They also observed chimpanzees ranging from age one to 51 living wild in the Budongo Forest in Uganda for comparison.
“Wild chimpanzees, gorillas, bonobos and orangutans all use gestures to communicate their day-to-day requests, but until now there was always one ape missing from the picture – us,” senior author Catherine Hobaiter from the School of Psychology and Neuroscience at the University of St. Andrews in Scotland said in a statement. “We used exactly the same approach to study young chimpanzees and children, which makes sense – children are just tiny apes.”
In total, researchers found the human toddlers used 52 discrete gestures to communicate, including clapping, hugging, stomping, raising their arms and shaking their heads, often stringing the moves together to convey complex ideas. It turns out that the chimps also used 46 of the same gestures, meaning there’s a 90 percent overlap.
“We thought that we might find a few of these gestures—reaching out your palm to ask for something or sticking your hand up in the air—but we were amazed to see so many of the ‘ape’ gestures used by the children,” Hobaiter says in the press release.
The human children did have some gestures that the apes did not. For instance, waving was common with the humans but absent in apes, and finger pointing is also common for the tots but rare in the apes.
The finding is not surprising since Homo sapiens and the other apes share a common ancestor dating back 5 or 6 million years ago. While the apes retain many of these gestures as a form of communication as they get older, the development of language makes them less important for adult humans, though some of us still occasionally stomp in frustration or reach out for a hug to show affection.
This isn’t the only recent study showing commonalities between great apes and people. Nell Greenfieldboyce at NPR reports that a recent study in The Proceedings of the Royal Society B researchers found that bonobos show signs of generosity and willingly offer food to one another, something almost unheard of when it comes to another great ape relative, chimpanzees, who almost never part with food. It’s an extremely rare trait shared with human children, who will spontaneously offer food to friends and adults.