Chimps share ‘building blocks of musical rhythm’ with humans

Musicality may have emerged in a common ancestor of chimps and humans, as both species share similarities in how they drum.

Catherine Hobaiter at the University of St Andrews, UK, and her colleagues examined 371 examples of drumming from two of Africa’s four chimpanzee subspecies: the western chimpanzee (Pan troglodytes verus) and the eastern chimpanzee (Pan troglodytes schweinfurthii).

They use their hands and feet to produce rapid-fire drumming, often on buttress roots and mainly when resting, while travelling or during threat displays.

Hobaiter says that while chimpanzees drum regularly, rainforests are really difficult places to carry out studies and for some of the populations, it has taken decades to collect the data.

Eventually, the researchers found that chimps drum much faster than most humans. “The longest drum we recorded was over 5 seconds, while the shortest was less than 0.1 seconds,” says Hobaiter. “But chimpanzees will also repeat these drumming bouts several times, especially when they’re travelling.”

Despite the differences between chimpanzee and human drumming, chimps show some of the “core building blocks of human musical rhythm”, says team member Vesta Eleuteri at the University of Vienna, Austria.

“They drum with rhythm, as opposed to randomly, and they use a typical rhythm observed across musical cultures called isochrony, consisting of hits that are regularly spaced, like the ticking of a clock,” she says. “We also found that the two eastern and western chimpanzee subspecies living on the opposite sides of Africa drum with different rhythms.”

She says eastern chimpanzees alternate short and long spaces between their drumming hits, while western chimpanzees evenly space them. These chimps also drum faster, use more hits and start drumming earlier in their distinctive pant-hoot calls.

Miguel Llorente at the University of Girona in Spain says the idea that different subspecies show distinct drumming styles is fascinating. “It opens the door to thinking about these patterns not just as individual quirks, but potentially as cultural differences in how groups use drumming as a communicative tool.”

We already know that rhythm is fundamental to human social behaviour – whether in music and dance or in the back and forth of a conversation, says Hobaiter. “We don’t mean that chimpanzee drumming shows the sophistication of modern human musical rhythms. But this is the first time that we’ve been able to show that they share the same rhythmic building blocks, making it likely that rhythm was a part of our social world long before we became human.”

“Until recently, it was argued that rhythmicity was unique to humans,” says Gisela Kaplan at the University of New England, Australia. “We now have plenty evidence that this is not the case.”