Just like humans, chimps learn to ‘talk’ by copying their elders

A study led by researchers at the CNRS Institute of Cognitive Sciences in Lyon and the Taï Chimpanzee Project in Ivory Coast has found that wild chimpanzees learn when to use a specific vocalization — an unvoiced raspberry-like sound — from adult role models, challenging the long-held view that chimpanzee calls are fixed, species-wide biological inheritances.

Wild Taï chimpanzees used the raspberry call almost exclusively during grooming, while the orphaned juveniles at Tacugama used it chaotically across different social interactions. This divergence indicates the call's grooming function is learned rather than innate. When an adult chimpanzee was introduced to one orphan group at Tacugama, the group's use of the call became markedly more uniform over time, converging on the pattern used by the new adult. "This means there's more continuity between chimpanzees' vocal learning and our own than we previously suspected," said Richard Moore, a University of Warwick-based philosopher and co-author of the study.

The findings suggest chimpanzee vocal communication shares key features with human language: words are largely learned and arbitrary, varying across communities as linguistic conventions. While chimpanzees appear to struggle to learn entirely new call sounds — suggesting parts of their repertoire are innate — they do learn at least some call functions from older community members. "Even aspects of chimpanzee vocal communication that seemed fixed and unlearned may be shaped by learning, suggesting that there is still much to discover about their vocal repertoire," said Antoine Valet, first author of the study. Cédric Girard-Buttoz, a senior author, added that recent research strongly suggests chimpanzees may even learn to combine calls into sequences.

Researchers noted that all wild chimpanzee populations appear to use the raspberry call in the same grooming context, unlike the variation seen in human languages. One hypothesis is that the call has a non-communicative origin — such as oral movements for removing parasites during grooming — that makes it especially likely to be adopted in that context, leading different groups to converge independently on the same pattern. However, this would not undermine the conventional nature of the call, since groups could have settled on different signals. Roman Wittig, director of the Taï Chimpanzee Project and a senior author, emphasized that preserving wild chimpanzee populations is critical to understanding the extent to which they learn and perpetuate their vocal communication.