A recent study suggests that human laughter shares distinctive rhythmic patterns with the giggles of great apes, indicating that this form of vocal expression may have been present in a common ancestor dating back around 15 million years. The research, led by primatologist Chiara De Gregorio at the University of Warwick, involved analyzing recordings of 13 captive great apes—including gorillas, orangutans, chimpanzees, and bonobos—being tickled. These sounds were then compared with newly captured laughter from four young children during tickling and play at home.

The analysis revealed that both human and great ape laughter exhibit similar timing intervals between individual laughs, supporting the idea that certain features of laughter have deep evolutionary roots. Unlike many other animals that emit sounds when tickled—such as rats, which produce ultrasonic squeaks—great apes and humans share a more comparable laughter pattern. Researchers have noted that while human laughter has evolved to become faster and more complex, adapting to different social contexts from polite chuckles to hearty guffaws, the fundamental rhythmic structure remains aligned with that of our closest primate relatives.

“In a way, we are very similar to other great apes because we’ve been laughing in a similar way for 15 million years,” said De Gregorio, whose findings were published in Communications Biology.

Brittany Florkiewicz, an expert in animal communication at Lyon College who was not involved in the study, described the findings as plausible and called for further research. She emphasized the potential value of studying laughter-like vocalizations in other animals known to display playful facial expressions, such as dogs, horses, and cats. Such comparative studies could help clarify which aspects of laughter are uniquely human and which are shared more broadly among social species.

The study contributes to ongoing efforts in understanding the evolutionary origins of laughter, a form of nonverbal communication that conveys positive emotions and may offer insights into the development of human social interaction and language. Since vocal sounds do not fossilize, researchers rely on behavioral observations and acoustic analyses like this to trace the lineage of laughter and its role in animal and human communication.