If a bonobo and a chimpanzee were to meet face to face, they might be able to understand each other’s gestures, according to a new PLOS Biology study.
Chimps and bonobos are closely related and were already known to share many gestures. However, while many gesture meanings were already known for chimpanzees, the meanings of a number of bonobo gestures were not defined.
In this study, the authors defined the meanings of 33 bonobo gestures by observing the response that they elicited. For example, a bonobo might gesture to a recipient until the recipient performs a certain action. If this occurs in multiple observations, then the gesture is read as requesting that action.
The researchers noted that gestures are mostly used by bonobos to start or stop social interactions such as grooming, travelling, or sex, including gestures to mean “follow me,” “initiate grooming,” and “move closer.” Their online Great Ape Dictionary features videos and diagrams of many such gestures.
When the study authors compared bonobo gesture meanings to known chimpanzee gesture meanings, they found that many meanings appear to be shared by both species. Lead author Kirsty Graham, from the University of York, notes that “the overlap in gesture meanings between bonobos and chimpanzees is quite substantial and may indicate that the gestures are biologically inherited,” though they might also be learned by other means such as imitation.
The scientists suggest that these gestures and meanings were likely also used by the last common ancestor we shared with these species. In future, they hope to examine whether humans share any of these great ape gestures or can understand their meanings.
Research Article: Graham KE, Hobaiter C, Ounsley J, Furuichi T, Byrne RW (2018) Bonobo and chimpanzee gestures overlap extensively in meaning. PLoS Biol 16(2): e2004825. https://doi.org/10.1371/journal.pbio.2004825
Images Credits: Catherine Hobaiter, Graham et al.