Chimpanzees and humans are even more alike than we knew. In a new study published today, scientists provide evidence that chimpanzees regularly communicate by gesturing to others in a rapid back-and-forth manner, much like how humans converse. The findings suggest that the evolution of chimp communication and human language have a lot in common with one another, the scientists say.
Researchers at the University of St Andrews in the UK have been studying gestures in chimps for some time. While past studies have focused on individual chimp gestures, this research aimed to better understand how two chimpanzees communicate with each other using gestures. With the help of other scientists, they managed to collect observational data from wild chimpanzees across five communities in East Africa.
Human-like patterns and pace
“This is the first time we could look at features of gesture exchanges across so many groups. It was a huge collaborative effort,” lead author Gal Badihi, a research fellow at St Andrews, told Gizmodo in an email.
All in all, the team analyzed more than 8,500 gestures from 252 chimpanzees. Gestures between two individual chimpanzees made about 14% of these communications. And the pattern and pace of these gestures were remarkably similar to that of a typical human conversation, the researchers found (an example can be seen in the video below).
“Chimpanzees take turns to gesture and leave almost no time between turns—a bit like how we take turns to speak in conversations. This is true across chimpanzee groups as well as across human cultures/societies, and rapid timing between turns is similar in both species,”” Badihi explained, saying it’s between 100 and 300 milliseconds. “We also found that even though all chimpanzees take fast turns, one group was a little slower than the others. This also matches slight variation between human societies with some groups being slow or fast talkers.”
An ancestral feature?
The team’s findings, published Monday in Current Biology, suggest that some of the unspoken rules that underlie human language are rooted in a deeper ancestral past that we share with chimps and possibly other animals, the researchers say.
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“This shows that other social animals don’t need language to communicate in a coordinated and structured way,” Badihi said. “Chimpanzee gestural communication and human language could have followed similar evolutionary paths to arrive at this fast-paced communicative strategy.”
At the same time, chimpanzee communication almost certainly does differ in important ways from human language. Only a small percentage of chimp gestures featured this rapid back-and-forth (14%), for instance, as opposed to it being a constant feature of human communication. So it’s likely that this structure has a different function for them than it does for us.
Aside from learning more about these gestures in chimpanzees, the researchers next hope to study whether this style of communication is routinely present among other members of the ape family and beyond. In the meantime, it’s nice to know that we’re not the only ones that love to gab back and forth at the local water cooler.
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