It used to be conventional wisdom that the use of tools was a uniquely human trait, but over time we learned that our closest primate relatives, and even non-primates such as birds are able to use external devices to accomplish various tasks.
And while spoken language remains a behavior that sets us apart from other members of the animal kingdom, a just-published study indicates that one of the most universally recognizable pieces of non-verbal communication, a shake of the head to mean “no,” may bear a distinct meaning not just for humans alone.
BBC reports of a study conducted in Germany and recently published by the journal Primates. In observing the behaviors of bonobo chimpanzees, scientists from the Max Planck Institute for Evolutionary Anthropology in Leipzig and the Freie Universität in Berlin found that the great apes give a shake of the head, precisely as we do, when they mean “no.” As BBC reports, the gesture was observed when an individual expressed to another that they did not want them to perform a particular action. For example, a bonobo mother was observed shaking her head to dissuade her young charge from playing with its food.
While head gestures have long been observed to play a role in bonobo interactions, the findings represent the first scientific evidence that goes beyond anecdotal indicators to link the bonobo’s use of a side-to-side head shake to indicate negation.
The researchers are cautious to characterize their observations as definitive proof of the equation between head shake and the concept of no; BBC points out that the matter isn’t even settled among people, noting that the side-to-side head shake means “yes” in Bulgaria.
Still, the findings may provide an opportunity to use behaviors among our nearest relatives to shed light on patterns of human behavior and communication. As quoted by BBC, study author Christel Schneider observes:
“If future research can confirm the use of preventive head-shaking in our closest living relatives, the bonobos and chimpanzees, then this would raise the question of whether these gestures reflect a primitive precursor of the human ‘no’ head-shake.”
Photo by Evanmaclean via Wikimedia Commons.
