Human laughter, characterized by rapid and rhythmically timed bursts, is not exclusive to humans. Recent research from the University of Warwick and the University of Portsmouth reveals that all great apes, including orangutans, gorillas, and chimpanzees, share the same fundamental timing structure for laughter. This finding indicates that our common ancestor with these great apes was capable of recognizable smiling at least 15 million years ago.
Analysis of laughter tempo in five great ape species: orangutans, gorillas, bonobos, chimpanzees, and humans. Points represent individual observations, with color coding for evolutionary distance. Image credit: De Gregorio et al., 10.1038/s42003-026-10499-z.
Chiara de Gregorio, a researcher at the University of Warwick, stated, “Sounds do not fossilize, complicating the traceability of song sounds, spoken words, and languages.”
She added, “Comparative studies of the behaviors of our closest living relatives, the (non-human) great apes, serve as the only extant model for the vocal abilities and adaptive features that our ancestors may have lost.”
“Although every major hominid lineage has developed unique vocalization repertoires shaped by their specific social ecologies, laughter remains a conserved vocalization across species and age-sex categories.”
This study recorded laughter in various tickle play and social play scenarios involving 17 individuals from all five great ape species.
The research comprised four orangutans, two gorillas, three bonobos, four chimpanzees, and four humans, including children aged 6 months to 7 years.
Analysis showed that laughter across all species is isochronous, meaning it occurs at regular, evenly spaced intervals. This rhythm mirrors those found in music and speech.
Scientists have confirmed that this fundamental rhythmic structure was already present in our common ancestor 15 million years ago and continues to be remarkably conserved across modern great apes.
However, they identified noteworthy differences along the evolutionary line. The closer a species is to humans on the evolutionary tree, the faster and more variable their laughter becomes, with increased sensitivity to social contexts.
Humans were unique in adjusting the tempo of their laughter depending on whether they were engaged in tickling or free play.
The researchers noted that variations in human laughter tempo are perceived as more emotionally warm and socially positive, indicating that rhythmic flexibility holds significant social implications.
Dr. Adriano Lamelia from the University of Warwick remarked, “Assessing the vocal forms of extinct ancestors directly is impossible.”
“Laughter is an evolutionarily ancient trait shared by all extant great apes, providing a valuable evolutionary perspective on vocal changes that occurred throughout human evolution leading to the emergence of the first humans.”
“This research counters the classical view that the first humans suddenly acquired distinct vocal control abilities; instead, the evolution of laughter illustrates the continuum of vocal control capabilities that developed cumulatively over 15 million years.”
For further details, refer to the findings published in the Journal on June 25, 2026, in Communication Biology.
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C. De Gregorio et al. 2026. The rhythm and timing of laughter reveal that human vocal plasticity is part of the hominid continuum. Comm Biol 9,824; doi: 10.1038/s42003-026-10499-z
Source: www.sci.news
