Aping of Different Kind: Contagious Yawn in Bonobos in Close Relation

Humans are not exclusive with the habit of contagious yawning. The habit of contagious yawning has been found from humans to dogs. Yawning is more common when individuals are closely related. The same phenomenon exists in Bonobos.

According to the new study by Elisabetta Palagi and Elisa Demuru from the University of Pisa, Italy, being socially close to another bonobo is more likely to make bonobo apes yawn in response to the other's yawns. 

It was observed by the researchers that yawning in bonobos was more contagious when individuals were strongly bonded to one another as kin or close friends. 

When the individuals are relaxed the yawn contagion was higher, and it occurred in every context when the first yawner was a senior member of the group.

Prior to this there were studies that found a similarresults in humans, showing that a person is more likely to yawn when family or close friends do, rather than in response to a stranger's yawning. 

It is assumed that yawn contagion was a mode for the social groups to communicate and coordinate activities. But this has a unique emotional component as it appears to occur more frequently between closely bonded individuals. 

The authors say, "Though we are still far from a clear demonstration of a link between yawn contagion and empathy, the importance of social bonds in shaping this phenomenon in bonobos suggests that a basic form of empathy may play a role in modulating yawning behavior."

This study was published in on Nov. 14 in the open access journal PLOS ONE.