Great apes of all species — human and non-human — communicate using a combination of different types of signals: vocalizations, gestures, facial expressions and body postures. According to a new study, published in the journal Animal Cognition, one- to two-year-old human children use many of the gestures observed in great apes. The study, led by University of St Andrews researcher Catherine Hobaiter, showed that children used 52 gestures to communicate, 46 (89%) of which are shared with chimpanzees. Like chimpanzees, children used them both singly, and in sequences, and employed individual gestures flexibly towards different goals.
The bonobo (Pan paniscus). Image credit: Pierre Fidenci / CC BY-SA 2.5.
Dr. Hobaiter and her colleagues from the UK, Uganda, Germany and Switzerland studied young children and chimpanzees.
Chimpanzees were observed in their habitat, the Budongo forest in Uganda, and young children were observed in their nursery and home environments.
Wild great apes use over 80 different gestures, and scientists have recently completed a ‘great ape dictionary’ to investigate what they mean.
“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,” Dr. Hobaiter said.
“We used exactly the same approach to study young chimpanzees and children, which makes sense — children are just tiny apes.”
The study authors were surprised by just how many gestures the children had in common with our ape cousins.
“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,” Dr. Hobaiter said.
The researchers found that like young apes, the young children used these gestures in a similar way: combining them together to ask for different things.
They also found some differences — young children use pointing gestures far more than young apes, and waving your hand (to say hello or goodbye) seems to be uniquely human.
“Since chimpanzees and humans shared a common ancestor around 5-6 million years ago, we wanted to know whether our evolutionary history of communication is also reflected in human development,” said study first author Dr. Verena Kersken, a scientist at the University of Göttingen in Germany.
“While humans developed language, it appears that we still have access to this shared ancient gestural heritage — and gestures continue to play an important role before language is fully developed.”
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Verena Kersken et al. A gestural repertoire of 1- to 2-year-old human children: in search of the ape gestures. Animal Cognition, published online September 8, 2018; doi: 10.1007/s10071-018-1213-z
