New research shows chimps ‘talk’ with their hands just like humans

By Stephen Beech via SWNS

Chimpanzees "talk" with their hands - just like humans, reveals new research.

The primates gesture back and forth quickly as people do during conversations, say scientists.

They explained that when humans are having a conversation, they rapidly take turns speaking and sometimes even interrupt each other.

Now a Scottish-led research team that has collected the largest ever dataset of chimpanzee “conversations” has found that the apes communicate back and forth using gestures following the same rapid-fire pattern.

Ape expert Dr. Catherine Hobaiter, of the University of St. Andrews, said: “While human languages are incredibly diverse, a hallmark we all share is that our conversations are structured with fast-paced turns of just 200 milliseconds on average.

“But it was an open question whether this was uniquely human, or if other animals share this structure.”

Study first author Dr. Gal Badihi, also of the University of St Andrews, said: “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."

The researchers knew that human conversations follow a similar pattern across people living in places and cultures all over the world.

They wanted to know if the same communicative structure also exists in chimps - even though they communicate through gestures rather than through speech.

To find out, they collected data on chimp “conversations” across five wild communities in East Africa.

They measured the timing of turn-taking and conversational patterns after collecting data on more than 8,500 gestures for 252 individuals.

Their findings, published in the journal Current Biology, showed that 14% of communicative interactions included an exchange of gestures between two interacting individuals.

The researcher said that most included a two-part exchange, but some included up to seven parts.

Overall, the data revealed a similar timing to human conversation, with short pauses between a gesture and a gestural response at about 120 milliseconds. Behavioral responses to gestures were slower.

Dr. Badihi said: “The similarities to human conversations reinforce the description of these interactions as true gestural exchanges, in which the gestures produced in response are contingent on those in the previous turn.

“We did see a little variation among different chimp communities, which again matches what we see in people where there are slight cultural variations in conversation pace: some cultures have slower or faster talkers."

Dr. Hobaiter said: “Fascinatingly, they seem to share both our universal timing, and subtle cultural differences.

“In humans, it is the Danish who are ‘slower’ responders, and in Eastern chimpanzees that’s the Sonso community in Uganda.”

The research team says the correspondence between human and chimpanzee face-to-face communication points to shared underlying rules.

They noted that the structures could be traced back to shared ancestral mechanisms.

The team believes that it’s also possible that chimps and humans arrived at similar strategies to "enhance" coordinated interactions and manage competition for communicative “space.”

The researchers say their findings also suggest that human communication may not be as unique as previously thought.

Dr. Badihi said: “It shows that other social species don’t need language to engage in close-range communicative exchanges with quick response time.

“Human conversations may share similar evolutionary history or trajectories to the communication systems of other species suggesting that this type of communication is not unique to humans but more widespread in social animals.”

Now the team wants to explore why chimps have such conversations to begin with.

They believe chimps often rely on gestures to ask something of one another.

Dr. Hobaiter added: “We still don’t know when these conversational structures evolved, or why.

“To get at that question we need to explore communication in more distantly related species - so that we can work out if these are ape-characteristic, or ones that we share with other highly social species, such as elephants or ravens.”