Humans recognise ape gestures
Scientists have known for a long time that humans and other apes, such as chimpanzees, have lots of physical similarities. Now, new research has shown that we may also share a language – because we use the same physical gestures (signs) to communicate.
Researchers already knew that great apes (a family of apes very closely related to humans, including bonobos, chimpanzees and gorillas) have more than 80 gestures that they use to communicate with each other. Scratching their chests is a way to say “groom me” to another ape; pointing fingers down beside them means “come here”. They might also ask for food from each other by cupping a hand under another ape’s chin. To test if humans can understand these gestures, scientists from the University of St Andrews in Scotland gathered a group of 5,656 volunteers. They were shown 20 videos of chimpanzees and bonobos making their 10 most common gestures. One group of people were given a bit of information about what the apes had been up to – such as eating or resting before they made each gesture; the other group of people were not. After watching each video, everyone had to choose from a list of four possible answers what they believed the apes’ gestures were communicating. The average success rate was 57% if information was given and 52% if not. This suggests it wasn’t just luck and that humans tend to understand what apes’ gestures mean. Some of the gestures had several meanings but people were just as good at understanding them.
Scientists need to do more work to find out exactly why humans understand the gestures. Researcher Kirsty Graham told the Scientific American website that it could be something we shared with our last common ancestor. It is also possible that although humans evolved to have a spoken language, perhaps we kept our ability to use gestures to communicate.