Fast and many. That's how chimpanzees' gestures are when they converse with each other. Just like humans, waving movements are a natural part of communication, according to new research.
That chimpanzees are like us is no news. Now, researchers from the USA, Germany, and Japan have found another common denominator between us and our hairy relatives. They have studied 250 wild chimpanzees from different groups in East Africa, focusing on how they communicate.
The researchers have seen that just like humans, chimpanzees use different types of gestures when communicating with each other. Like us, they take turns gesturing during a conversation.
Just as there are cultural differences among humans when it comes to the extent to which we use gestures when speaking, the researchers saw differences between different chimpanzee groups. In some groups, they conversed faster, and in others, more slowly.
"Among humans, it's the Danes who are a bit slower. Among chimpanzees, it's the Sonso group in Uganda," says Gal Badihi, one of the researchers behind the study, which has been published in the journal Current Biology.
The researchers have, among other things, measured the number of gestures and the time between gestures in chimpanzees. They saw that 14 percent of interactions contained an exchange of gestures between two individuals. Just like humans, the researchers saw that they have short pauses between a gesture and another chimpanzee's response gesture, on average 120 milliseconds. It also happens that they interrupt each other.
A difference between humans and chimpanzees is that we also use gestures to reinforce and explain, while chimpanzees often do it to prompt action, the researchers write.