[People laughing at comedy show]
[Gorilla being tickled and laughing]
[A mountain gorilla eating leaves in the forest of Bwindi Impenetrable National Park in southwestern Uganda]
[Audio of a gorilla laughing]
[A mountain gorilla eating leaves in the forest of Bwindi Impenetrable]
[National Park; audio of a gorilla laughing]
[Orangutans in North Sumatra’s Gunung Leuser National Park near Bukit Lawang, Indonesia]
[Audio of orangutan laughing]
[Orangutans in North Sumatra’s Gunung Leuser National Park near Bukit Lawang, Indonesia; audio of an orangutan laughing]
[A bonobo gesturing at the Lola ya Bonobo sanctuary in Kinshasa, Democratic Republic of the Congo]
[Audio of bonobo laughing]
[A bonobo gesturing at the Lola ya Bonobo sanctuary; audio of a bonobo laughing]
[A chimpanzee eating its food at the Central Zoo in Lalitpur, Nepal]
[Audio of chimpanzee laughing]
[A chimpanzee eating its food; audio of a chimpanzee laughing]
Chiara de Gregorio (interview): “We say that all the species have an isochronous rhythm, meaning that if you think of a metronome, the tick, tick, tick, the regularity is there. So it’s always the same interval going between laughter bursts. But for example, this metronome can go faster or slower. So in human laughter, it’s more like ‘tick, tick, tick, tick,’ and in orangutans, the slowest, it’s like ‘tick, tick, tick’. So different pace, different tempo, but it’s always regular. So always the same duration between different following sounds.”
[Gorillas feeding in Bwindi Impenetrable Forest]
Chiara de Gregorio (interview): “So we could say that finding similarities like commonalities in human and all the great apes until orangutans, there will be that kind of feature, that regularity that was really hardwired into our evolution because it was something that we’ve really been doing for 15 million years, so must be a very strict and important feature of the way we laugh.”
[Orangutans]
[Bonobos in sanctuary]
Chiara de Gregorio (interview): “So in a way we are very similar to other great apes because we’ve been laughing in a similar way for 15 million years. But at the same time, we realize that our laughter holds more information, that is simple, I’m playing and having fun. And it’s something that maybe we don’t think about in everyday life, how we could communicate so many things without words.”
[Chimps]
Brittany Florkiewicz (interview): “The results of this study make a lot of sense in terms of what we’ve been seeing with humans as well as non-human primates. So, as a whole, we’re seeing that there are some similarities across great apes, including humans, in the fact that there is regular timing between that first ha and the second ha. And again, because there are benefits to play faces, relaxed open mouth faces, and the vocalizations that go with them, it makes sense that this particular feature, that regular timing, will be evolutionarily conserved or widespread among animals because everyone potentially benefits from this.”
[People laughing]
This script was provided by The Associated Press.