Great apes may laugh at a rhythm similar to that of modern humans, a study suggests, and the phenomenon has lasted for at least 15 million years. The findings also suggest that over the course of great ape evolution, laughter became faster, more varied and increasingly influenced by context. Relevant research results were published in "Communications-Biology" on June 25.
All great apes (hominids) laugh, including species closely related to humans, such as bonobos, and more distantly related species, such as the Bornean orangutan. However, it was previously unknown how the rhythm of laughter evolved over time and how it might relate to the evolution of human language.
In the study, Chiara De Gregorio of the University of Warwick in the UK and colleagues analyzed recordings of laughter from four Bornean orangutans (Pongo pygmaeus), two gorillas (Gorilla gorilla), three bonobos (Pan paniscus), four chimpanzees (Pan troglodytes) and four humans, aged between 6 months and 7 years old.
Scientists studied 140 laughter sequences and measured the time between each utterance. The study found that laughter in all species follows a regular rhythmic pattern, with even intervals between successive vocalizations. Because this pattern was present in all species studied, the researchers speculated that this rhythmic laughter may have been present in their common ancestor as early as 15 million years ago.
They also theorize that laughter has become faster and more diverse over time, with humans changing the pace of their laughter depending on the situation, such as laughing faster when being tickled than when playing, while other apes do not. Furthermore, the more closely related apes are to humans, the greater the variability in their laughter rhythms.
These findings suggest that vocal flexibility and control may have gradually increased during the evolution of great apes and humans, and the authors speculate that this may have contributed to the emergence of language. Future studies with larger sample sizes will need to confirm these findings.
Related paper information: https://doi.org/10.1038/s42003-026-10499-z