After analyzing thousands of wild chimp-to-chimp gestures, University of St Andrews researchers believe that they have translated the meanings of 36 chimpanzee gestures that are used to communicate. According to the researchers, this is the first time that another animal communication system has been found to have meaning. Furthermore, this novel information may also offer an insight into the evolution of human language. The study has been published in Current Biology.

While previous research has found that apes and monkeys are able to understand information conveyed by the call of another animal, it did not appear that voices were used intentionally to communicate messages. This is the crucial difference between calls and gestures, lead researcher Catherine Hobaiter told BBC News, since chimps use gestures as a communication system to convey messages to others.

“That’s what’s so amazing about chimp gestures,” said Hobaiter. “They’re the only thing that looks like human language in that respect.”

In order to conduct this study, Hobaiter spent 18 months observing a group of wild chimpanzees in the Budongo rainforest in Uganda. She and colleague Richard Byrne then analyzed more than 4,500 chimp exchanges in order to decipher what the gestures could mean.

They found that chimpanzees use 66 gestures to deliberately communicate 19 meanings. The researchers were also able to assign true meanings for 36 of these gestures. For example, if the chimps wanted to play, they would stomp both feet, or if they wanted contact they would hug the air.

Some of the gestures were used to convey only one meaning, such as leaf clipping which is used to elicit sexual attention, whereas others were more ambiguous and could have several meanings. Grabbing another chimp, for example, is used to communicate: “Stop that,” “Climb on me,” and “Move away.” Furthermore, several different gestures could also be used for one meaning.

“What we’ve shown is a very rich system of many different meanings,” Byrne told Wired. “We have the closest thing to human language that you can see in nature.”

The researchers acknowledge that their study was limited by the fact that they could only assign meanings to gestures that provoked an action, meaning that there are probably many more subtle gestures that cannot be interpreted. Furthermore, it has been pointed out that the vague nature of some of the meanings likely means that we are missing a lot of information contained within these gestures.

Still, the researchers are confident that their work has merit. “The big message is that there is another species out there that is meaningful in its communication, so that’s not unique to humans,” said Hobaiter. “I don’t think we’re quite as set apart as we would perhaps like to think we are.”

[Via BBC, Current Biology and Wired]