Similar to how we humans usually adopt the way of speaking and dialect from our environment, the grunting sounds of baboons also differ slightly depending on the social group, as primate researchers have found out. According to this, the calls of Guinea baboons from the same social unit are more similar than the sounds between the social groups. These “accents” are presumably due to vocal learning, which we humans also use for language acquisition.
We humans are particularly good at imitating sounds we hear and adapting our speech to our surroundings. This so-called vocal learning is the prerequisite for each of our spoken words and also for singing masterpieces. We humans can change the way we speak or learn new languages into old age. But animals such as songbirds and bats also learn complex forms of acoustic communication and even develop “dialects” in the process.
Do monkeys master vocal learning?
“Language acquisition” has so far been less clear in monkeys and great apes – also because their repertoire of sounds is relatively limited. To find out whether these non-human primates also show a form of vocal learning, a team led by Julia Fischer from the German Primate Center in Göttingen has now analyzed the sound structures of baboons. The researchers wanted to find out whether social and acoustic experiences shape the “language” of these animals and thus draw conclusions about the evolution of vocal learning.
To do this, they observed Guinea baboons (Papio papio) from the Niokolo Koba National Park in Senegal. Baboons of this kind live in multi-level societies in which several males form groups with their females and young animals and two to three of these groups form a “gang”. During companionable interactions with other group members, the males typically emit low-frequency grunts that indicate friendly intentions. The research team compared the acoustic structure of these sounds in 27 male baboons from two different gangs with two groups each and also determined the degree of relationship between the animals.
Each group has its own accent
The result: the sound analyzes showed that the grunts of males belonging to the same gang or group and thus the same social unit were on average more similar than the grunts of males of different social levels. As genetic analyzes have shown, these linguistic similarities are not due to a close relationship.
Instead, according to the researchers, the degree of social interaction determines the sound structure: They suspect that the accent of the baboons could be a simple form of vocal learning, in which the hearing experience determines the expression of the calls. This leads to the group-specific “accents” of the baboon sounds.
“People do that too: they often involuntarily adjust the tempo or their pitch in order to get closer to the person you’re talking to,” explains Fischer. Behind this vocal adaptation, there is no intentional, but implicit learning, say the scientists. “Non-human primates and humans seem to share this effect. But that is far from learning the first word – or mastering an entire language, ”sums up the researcher. “Therefore, if you want to understand the evolution of language, it is important to distinguish between different forms of vocal learning.”
Source: Deutsches Primate Center GmbH – Leibniz Institute for Primate Research, Article: Proceedings of the Royal Society B, doi: 10.1098 / rspb.2020.2531