People may notice that their accents have changed albeit subtly when they spend sufficient time in a different country. Interestingly, this does not only happen to humans. It also occurs in chimpanzees.
Researchers have found that when groups of chimps combine, they have the tendency to adapt by imbibing new accents until they are all grunting the same way.
It was previously believed that this ability to modify vocalizations in order to fit in with social groups was an exclusive human trait, but findings of the new study, which was published in the journal Current Biology on Thursday, Feb. 5, revealed otherwise.
"It's the first time we've seen another primate species -- not humans -- change the structure of the call that they gave for a specific object by socially learning it," said study researcher Katie Slocombe, a psychologist from the University of York.
For the new study, Slocombe and colleagues wanted to find out what would happen after two separate groups of adult chimps merged at the Edinburgh Zoo. Prior to the two groups moving together, chimps on both groups have their particular food grunts.
Three years after the two groups moved in together, the researchers observed that the acoustic structure of the food grunts used by the two groups converged as members of both groups began to know each other.
Members of the newcomer group were likewise observed to have significantly changed their calls in order to match those used by the long-term residents, the researchers said.
"Following the integration of two groups of adult chimpanzees, the acoustic structure of referential food grunts produced for a specific food converged over three years," the researchers wrote. "Acoustic convergence arose independently of preference for the food, and social network analyses indicated this only occurred after strong affiliative relationships were established between the original subgroups."
As to why this happens, the researchers have a number of possible answers. One of these is that the chimps might be learning the foreign grunts with the aim of forming, maintaining and improving their social relationships with chimps belonging to a different group.
Study researcher Simon Townsend from the University of Zurich said it is also possible that the chimps change their grunts to ensure that the chimps from the other group can understand them correctly.
The researchers noted that additional studies will be needed in order to find out what exactly causes the chimps to be motivated so they would sound more like their group mates.
