Chimpanzees too “converse” in a back-and-forth style like humans, and use gestures, which suggests that the processes driving the evolution of communication in both species could be similar, a study has found.
Researchers explained that structured conversations are a “hallmark” of human communication, in which each person involved takes “fast-paced turns of 200 milliseconds on average.”
While humans around the world, across places and cultures, are known to follow similar conversational patterns, the researchers, including those at the University of St Andrews, UK, wanted to know if chimpanzees too follow these patterns, even though they are known to “converse” through gestures more than through speech.
For the study, the researchers collected data on chimpanzee conversations across five wild communities in East Africa and built a dataset of more than 8,500 gestures by 252 individuals, deeming it to be the largest ever of its kind.
On analysing the data, the researchers found that chimpanzees have a timing similar to that seen in humans – pauses of about 120 milliseconds each between a gesture and its response.
“We found that the timing of chimpanzee gesture and human conversational turn-taking is similar and very fast, which suggests that similar evolutionary mechanisms are driving these social, communicative interactions,” said Gal Badihi, University of St Andrews, and first author of the study published in the journal Current Biology.
The researchers also found that 14 per cent of the conversations involved an exchange of gestures between two interacting individuals. Most of the exchanges were found to include a two-part exchange, but some included up to seven parts.
Further, among the chimpanzees, the researchers found “subtle” cultural differences. “In humans, it is the Danish who are ‘slower’ responders, and in Eastern (African) chimpanzees, that’s the Sonso community in Uganda,” said author Catherine Hobaiter from the University of St Andrews.
The findings suggest that human communication may not be as unique as one might think, the authors said.
The similarities in chimpanzees’ and humans’ conversation styles point to shared rules of communication, which could be traced back to common ancestral processes, the researchers said.
“(The study) shows that other social species don’t need language to engage in close-range communicative exchanges with quick response time,” said Badihi.
