From pointing to arm movements and nodding, humans frequently use gestures to complement language.
Now, scientists suggest that humans can also understand the sign language used by chimpanzees.
According to a study published in PLOS Biology, chimpanzees use over 80 signals to communicate daily goals. These gestures include “big scratch,” which means “groom me.”
They perform this to remove insects or dirt from each other’s fur. “Shake the same kind” may mean “let’s have sex,” “groom me.”
Chimpanzees and bonobos – sharing over 90% similar gestures, are our closest relatives.
The study indicates that chimpanzees and bonobos, which share over 90% of similar gestures, are our closest relatives. According to author Kirsty E. Graham, a researcher at the School of Psychology and Neuroscience at the University of St. Andrews in Scotland, gestures in these species are believed to be an important framework in the evolutionary process of human language.
Researchers noted that infants aged 1 to 2 years use over 50 gestures similar to those of chimpanzees. Thus, it is suggested that humans may retain an understanding of core features in the gestures of these primates.
The researchers utilized data from 5,656 participants. These individuals watched 20 online videos featuring a gesture from either a bonobo or a chimpanzee and were asked to select the correct meaning.
Each video was accompanied by a simple illustration of the gesture, assisting viewers in identifying the action in the clip. Participants were found to successfully interpret the gestures of chimpanzees with over 50% accuracy. This figure is double what scientists expected.
The study’s authors concluded: “The ability of participants to interpret primate signals adds to recent findings that suggest humans can perceive emotional signals in primate vocalizations.”
According to author Graham, these gestures are shared by all other great ape species. Therefore, if humans can understand them, it appears that the remarkable gestural ability of these primates was utilized by our common ancestors. However, researchers note that the fundamental mechanisms that help humans understand chimpanzee gestures remain unclear.
Some explanations include the biological inheritance humans share with this primate species. Alternatively, chimpanzees and humans may have similarities in interpreting signals, as well as body plans and social goals. Researchers point out that humans can also understand the gestures of gorillas and orangutans.
