Apes use signals to begin and end social interactions, a new study has found.
An ape
The findings mark the first time the behaviour has been picked up outside of the human species and the researchers spotted evidence that could challenge the long-held claim that joint commitment is unique to the human race.
Researchers also discovered that social and power dynamics between interacting apes had an impact on the communication methods used and suggest it mirrors patterns similar to human politeness.
However, experts insist that there is still a lot of work to be done to understand joint commitment in other species.
Dr. Raphaela Heesen, a researcher from Durham University, said: "Behaviour doesn’t fossilise. You can’t dig up bones to look at how behaviour has evolved. But you can study our closest living relatives: great apes like chimpanzees and bonobos.
"Whether this type of communication is present in other species will also be interesting to study in the future."