Humans are surprisingly good at interpreting the meanings of gestures made by chimpanzees and bonobos, our closest living relatives, reports a first-of-its-kind study that quizzed more than 5,500 human participants about ape movements.
The results hint that humans may retain some level of fluency in a physical repertoire of gestures shared by many apes, suggesting that our own ancestors may have used similar motions to communicate before the emergence of our modern complex language.
Chimpanzees and bonobos, members of the Pan family of great apes, often communicate with physical movements that translate to messages such as “groom me,” “get on my back,” or “let’s be friendly.” Kirsty Graham and Catherine Hobaiter, who are both primatologists at the University of St Andrews, have carefully cataloged these motions in their research, which got them thinking about the implications of this gestural vocabulary in unraveling the origins of human language.
To probe this question, the pair enlisted 5,656 people to complete an online game that tested whether participants could interpret gestures produced by nonhuman apes in a series of videos, using a multiple-choice format for answers. The short quiz, which is still available at this link , offers “the first test of the hypothesis that language-competent adult humans still share access to ‘family-typical’ great ape gesture,” according to a study published on Tuesday in the journal PLoS Biology.