Human laughter may hold a deeper connection to our primate ancestors than previously realized, preserving a 15-million-year-old evolutionary legacy. New research from the University of Warwick suggests the rhythm of laughter has remained largely unchanged across millions of years, offering surprising new insights into the origins of human speech.
Great apes are humanity’s closest living relatives, and species including chimpanzees, bonobos, gorillas, and orangutans all produce laughter-like vocalizations accompanied by smile-like facial expressions.
For years, scientists have wondered whether these vocal expressions share a common evolutionary origin. To investigate, researchers analyzed laughter recordings from 17 apes and humans representing five species: four orangutans, two gorillas, three bonobos, four chimpanzees, and four humans. Examining 140 laughter sequences, they found that every species produced laughter with evenly spaced rhythmic intervals between sounds—a pattern that appears to have been inherited from a common ancestor.
“It is impossible to assess the precursor forms of language directly from our extinct ancestors,” said Dr Adriano Lameria, an Associate Professor with the Department of Psychology at the University of Warwick and a researcher with its ApeTank, said in a statement. “Laughter, being evolutionarily older and having remained shared between all living great apes, provides a rare evolutionary window into the vocal transformations that unfolded across hominid evolution until the first humans appeared on scene.”
“Contrary to the classic notion that the first humans suddenly acquired vocal control capacities remarkably different from their predecessors, laughter evolution tells us that humans lay on a continuum, a prolongation of vocal control capacities that were already being cumulatively honed in for 15 million years,” Lameria added.
The discovery suggests that this rhythmic connection and foundation of laughter was already present around 15 million years ago and has persisted through millions of years of evolutionary change.
“How did humans evolve the remarkable ability to speak? Speech leaves no fossils, and complex language exists only in our own species. But we’ve found a 15-million-year-old clue in an unexpected place: our laughter,” said Dr. Chiara De Gregorio, Honorary Research Associate, Department of Psychology, University of Warwick.
“Unlike speech, laughter is shared by all living great apes. By comparing how different species laugh, we can see that a basic rhythmic structure has remained unchanged since our last common ancestor. That’s extraordinary,” De Gregorio added.
Even though humans and apes share similarities—with ape vocalizations generally having a deeper resonance and tone—the underlying timing of laughter has remained remarkably stable over millions of years. What distinguishes humans is our greater voluntary control over laughter, allowing us to laugh intentionally in social situations in ways that our primate relatives cannot.
Scientists believe this increased vocal control may have played a key role in the evolution of speech. The human ability to precisely regulate vocal timing, tone, and expression is considered a fundamental component of producing complex spoken language.
The new findings challenge the idea that humans suddenly developed advanced speech abilities unlike those of earlier species. Instead, the research suggests that human communication evolved gradually, building upon vocal capacities that had already been developing in our ancient primate relatives.
Chrissy Newton is a PR professional and the founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on YouTube and on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton, Instagram: @BeingChrissyNewton, and chrissynewton.com. To contact Chrissy with a story, please email chrissy @ thedebrief.org.