New research has found that the 'conversational' style of chimpanzees matches that of humans.

Researchers from the University of St Andrews and an international group of colleagues used the largest-ever database of wild chimpanzee gestural communication to show that chimpanzees’ gestures and human languages share the same conversational structures. 

Humans typically leave just 200 milliseconds between the end of one speaker’s sentence and the other’s response. 

These conversation ‘gaps’ are so short that we don’t have the time to mentally process the last word someone said before we start to respond.

The research showed that chimps show a very similar pattern of behaviour in the gestures they make to communicate with each other.

Read More:

The researchers spent decades recording the behaviour of five communities of wild East African chimpanzees in rainforests and woodlands in Uganda and Tanzania. 

They collected over 8500 gestures from over 250 individuals to create the largest-ever database of chimpanzee gestures. 

As well as establishing that the timing of chimpanzee gestural exchanges are very similar to those in human languages, the researchers also discovered that the chimpanzees show small variations between communities. 

Professor Cat Hobaiter, a primatologist at the University of St Andrews, said “It’s amazing to see how close the chimpanzee and human timings were—and that, just like us, the chimpanzee sometimes even interrupted each other midway through a gesture. 

“The chimps had a bigger range in timings: the gaps ranged from interrupting the signaller 1600 milliseconds before they finished their gesture, to taking 8600 milliseconds to respond.  

“This could be because the chimps were in a natural setting, unlike the humans who were observed and so could express a wider range of behaviour - sometimes interrupting each other and other times taking a long time to respond.

"We’re still trying to work out why but the Sonso chimpanzees in the Budongo Forest Uganda seem to be the slow ‘talkers’ taking their time to reply, while just down the road the Kanyawara chimpanzees are speedier!”

The teams hope to look at this in other apes and species. 

They hope to work out why these gestural ‘conversations’ exist, for example, whether they are clarifications or even negotiations between the chimpanzees.

Conversation structure is a human universal, but it also shows cultural variation. Around the world, conversations in different languages show similar time intervals between conversation turns. 

In some languages, these conversation ‘gaps’ are shorter or longer. 

Research from The Max Planck Institute for Psycholinguistics shows that the average time for Japanese speakers was seven milliseconds while Danish speakers took 470 milliseconds to intervene. 

The universal nature of this conversation structure suggests this key aspect of language use evolved long ago and before language as we know it emerged- but it was an open question whether it was shared in other species.

Lead researcher Dr Gal Badihi says “We still don’t know when these human conversational timing patterns evolved and for what reason. 

“Looking into more distantly related species will be a great way to better understand when and why these conversational rules evolved.

"It’s fascinating to witness how chimpanzees interact with each other and the world. Their societies are quite similar to ours - they spend time in large groups, break up into smaller parties and then come back together.

“Communication helps chimpanzees avoid conflict and coordinate with each other. Their gestures allow them to communicate over short distances to achieve social goals in the moment. 

“So one chimpanzee could gesture to another that they want food, and the other might give them food or, if they feel less generous, respond by gesturing for them to go away. They might come to an agreement about how or where to groom. It’s fascinating, and done in just a few short gesture exchanges.” 

“This is quite different to how humans normally use conversations: to exchange ideas about the world without making specific requests from their conversation partner.”

Chimpanzees have been seen using tools in the wild and being able to solve problems, such as stacking objects to reach food which is too high up.

A number of researchers have taught chimpanzees to use sign language or language based on pictures, however critics argue that this doesn't count as 'true' language as it does not demonstrate understand words as abstract symbols that can be combined in meaningful new ways. They have shown the ability to answer questions, but not to ask them.

Researchers Ann and David Premack attempted to teach a chimp named Sarah by "purposefully removing key elements from a familiar situation", for example not giving the ape her food on time.

The chimp was able to understand questions posed through variously shaped and coloured pieces of plastic, each representing a word, as well as conditional sentences such as "if Sarah take apple then Mary give chocolate Sarah".

However, Sarah was not able to ask any questions, which the researchers put down to "the ape's failure is due to its inability to recognize deficiencies in its own knowledge", unlike a human child.