Bonobos employ a type of syntax presumed to be exclusive to humans

Bonobos combines calls in a complex way that forms clear phrases that indicate that this type of syntax is evolutionarily older than previously thought.

The human language is often said to be Characteristics of our speciesit is made up of a variety of building blocks. One core block is a syntax where meaningful units are combined into a long sequence like a statement. This is possible through the constituency in which the whole meaning comes from the partial meaning.

The composition itself is not unique to humans. for example, Chimpanzees combine calls Warn other people against snakes. However, so far, only “trivial compositionality” has been identified in non-human animals, with each unit being added independently to the overall meaning. For example, the phrase “blonde dancer” has two separate units of blonde, who are also dancers. Humans were also considered unique to have “non-obvious constructivity.” There, words of combination mean something different from their individual meanings. For example, the phrase “bad dancer” does not mean a bad person dancing.

The problem is that biologists didn’t have the tools to assign clear meanings to animal vocalizations. Melissa Vertt At the University of Zurich in Switzerland, I was not sure if the combination was trivial or minor.

Berthet and her colleagues learned and tweaked methods from linguistics in our closest living relatives. This included spending five months after 30 adult bonobos at the Kokoropoli Bonobo Reserve in the Democratic Republic of the Congo, recording almost 1,000 instances when the bonobos called out. Of these utterances, about half were combinations of at least two different call types, quickly paired in succession.

In a new step, the researchers focused on everything that was happening at the time of the call and in the minutes that followed. They recorded over 300 of these observations, including what the callers were doing at the time, what was happening in the environment, and the behavior of the audience after the speaker and voice was uttered.

To clarify the meaning of each call, they used linguistic techniques to create speech-type clouds, placing the utterances that occurred in similar situations closer together. “We’ve established this dictionary,” says Barthlett. “We have one voice and one meaning.”

Once I got this semantic cloud, I was able to see if the individual calls had a clear meaning in combination, and I found that the combination was closer to the unit in which it was created. Using this approach, they identified four compositional calls, three of which were clearly not trivial and their meanings did not overlap directly with the components. For example, “High Foot + Low Foot” combines call, which means “I’m paying attention to me” and “I’m excited to pay attention to me because I’m suffering.”

Almost all of Bonobos’ chatter was about coordinating groups, Berthlet says. Team Members Martin Thurbeck At Harvard University, this is because bonobos have the dynamics of fission fusion groups.

“For the first time in any animal species, there is clear evidence of non-obvious syntax, non-obvious constituency, and the game changes.” Mael Leroux At the University of Rennes in France. “It’s revolutionary. It’s basically the cornerstone of comparative linguistics, and for the next decade of evolutionary linguistics.”

Because language is a human communication system, this discovery does not mean that bonobos have language, says Berthet. “However, they show that they have a very complex communication system that is similar to human language.”

There is evidence now that both Chimps and Bonobos have a syntax. It is inevitable that the capabilities of this construct were inherited from the last common ancestor, Leroux says. “They just made it clear that this core building block is ancient, evolved at least 7 million years ago, and perhaps even older.”