08-07-2025
Chimps follow social fads like humans, study finds
Chimpanzees adopt pointless fads, just like humans, researchers have found.
The animals were seen wearing grass and sticks in their ears, after copying the habit from other chimps.
The practice serves no purpose and shows chimps are capable of socially transmitting arbitrary customs, making them more like humans than previously thought.
Dr Jake Brooker of Durham University, said: 'What's remarkable is that these customs have no obvious utility.
'This isn't about cracking nuts or fishing for termites – it's more like chimpanzee fashion.
'It mirrors how human cultural fads spread: someone starts doing something, others copy it, and it becomes part of the group identity even if it serves no clear purpose.'
Spontaneous behaviour
Researchers spotted the strange behaviour while observing 147 chimpanzees across eight social groups living in the Chimfunshi Wildlife Orphanage in Zambia, Africa.
The team discovered that five of the eight chimpanzees in the group started inserting grass or small sticks into their ears, while six began doing the same with their rectums. The behaviour – which has never been seen in the wild – appeared spontaneously and spread rapidly.
Dr Edwin van Leeuwen of Utrecht University, the Netherlands, said: 'In captivity, they have more free time than in the wild.
'They don't have to stay as alert or spend as much time searching for food. Why they do exactly this particular thing, I'm not really concerned about.
'But they are copying the behaviour from each other, that is the important insight.'
Culture predates humans
The findings suggest that culture may have evolved far earlier than humans, and that the roots of symbolic shared behaviour is embedded in primates.
Dr Brooker added: 'In copying these quirky actions, the chimpanzees may be helping strengthen social bonds or signal group belonging. That's something we see in human fads too.
'By studying the seemingly odd but socially meaningful behaviours of chimpanzees, we gain powerful insights into how our own cultures may have evolved.
'Our findings demonstrate just how much we still share with our primate cousins, and challenge the idea that symbolic or arbitrary traditions are uniquely human.'
