Wearing WHAT Where?! Chimps start the weirdest fashion trend

Published in Humor and Quirks on Saturday, July 19th 2025 at 7:43 GMT by New Atlas
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Humans love quirks. For example, eyebrow slashes, pup scarves, or TikTok moves with no practical use. Most of us don''t invent these things. We see them, we copy them. Voil : instant trend.

Chimps' Bizarre Fashion Fad: Grass Earrings Spark a Cultural Phenomenon in the Wild

In the lush forests of Zambia's Chimfunshi Wildlife Orphanage Sanctuary, a peculiar trend has taken hold among a group of chimpanzees, turning heads among primatologists and animal behaviorists alike. What began as an idiosyncratic habit by one innovative chimp has evolved into what researchers are calling a bona fide fashion statement – wearing blades of grass in their ears. This isn't just random play; it's a deliberate, socially transmitted behavior that highlights the surprising depths of chimpanzee culture, mirroring the whimsical trends that sweep through human societies. As we delve into this story, it becomes clear that our closest animal relatives aren't just surviving in the wild; they're styling, innovating, and passing on traditions in ways that challenge our understanding of animal intelligence and social dynamics.

The saga started back in 2010, when researchers first noticed a female chimpanzee named Julie engaging in an unusual activity. Julie would carefully select a long, stiff blade of grass, insert it into one of her ears, and leave it there as she went about her daily routines – foraging, grooming, or interacting with her troop. At first, it seemed like a quirky personal habit, perhaps a form of self-stimulation or an accidental discovery that felt good. But what happened next transformed this solitary act into a group phenomenon. Other chimpanzees in Julie's immediate social circle began to mimic her. They weren't just copying blindly; they observed, learned, and adopted the behavior with apparent intent, turning grass-in-ear into a shared accessory.

Leading the study was Edwin van Leeuwen, a primatologist from the Max Planck Institute for Psycholinguistics and Utrecht University, who documented this trend over several years. His team's observations, detailed in a paper published in the journal *Animal Cognition*, reveal that out of 94 chimpanzees across four groups at the sanctuary, only those in Julie's group – eight out of twelve individuals – adopted the grass-wearing habit. This specificity is key: neighboring groups, despite having access to the same grass and observing similar environmental cues, showed no interest in the fad. "It's not about the grass itself being inherently appealing," van Leeuwen explained in interviews. "Chimps use grass for all sorts of things – tools, nests, even play – but sticking it in the ear? That's novel and group-specific."

To understand why this matters, we need to step back and consider the broader context of animal culture. Culture, in the anthropological sense, refers to behaviors that are learned socially and passed down through generations, rather than being genetically hardwired or individually invented each time. In humans, fashion is a prime example: think of bell-bottom jeans in the 1970s or the recent resurgence of bucket hats. These trends spread via observation, imitation, and social influence, often without any practical purpose beyond signaling group identity or status. Chimps, it turns out, aren't so different. Julie's grass earring wasn't a tool for survival – it didn't help with hunting, protection, or mating. It was, in essence, arbitrary, much like a human donning a fedora for style points.

The transmission process was fascinating to watch. Julie's closest companions, including her son Jack and other females like Kathy and Val, were the first to pick it up. They didn't all do it exactly the same way; some used one ear, others both, and the grass varied in length and type. But the core idea persisted. Researchers noted that the behavior spread through high-affinity relationships – chimps who spent more time together were more likely to adopt it. This social diffusion echoes how human trends often start with influencers and ripple out through networks of friends and family.

Even more remarkably, the trend outlived its originator. Julie passed away in 2013, yet the grass-wearing continued among her group members. By 2014, when the study concluded, several chimps were still sporting their grassy accessories, suggesting that the behavior had become embedded in the group's cultural repertoire. "This persistence after the inventor's death is a strong indicator of true cultural transmission," van Leeuwen noted. It's akin to how human customs, like holiday traditions or slang, endure long after their creators are gone.

But why grass in the ear specifically? The researchers hypothesize that it could stem from sensory pleasure – perhaps the tickle or the weight provides a novel sensation. Chimps are known for their curiosity and playfulness; they've been observed using leaves as "hats" or sticks as "dolls" in other studies. However, this ear-grass trend stands out for its lack of functionality. It's not about camouflage, as the grass sticks out conspicuously. Nor is it tied to dominance displays or mating rituals, based on the observations. Instead, it seems purely aesthetic or social – a way to conform, stand out, or simply bond.

This discovery builds on a growing body of evidence for cultural behaviors in chimpanzees. Jane Goodall's pioneering work in the 1960s revealed tool use, like termite fishing with sticks, varying between groups. More recent studies have documented everything from nut-cracking techniques to greeting gestures that differ by community. The grass earring fad adds a lighter, more whimsical layer to this picture, showing that chimp culture isn't just about survival skills but also includes seemingly frivolous innovations. "It challenges the notion that culture is uniquely human," says Andrew Whiten, a professor of evolutionary and developmental psychology at the University of St Andrews, who wasn't involved in the study but has commented on similar findings. "These chimps are demonstrating arbitrary traditions, much like our own fashion cycles."

Comparisons to human behavior are inevitable and illuminating. Imagine if a celebrity like Beyoncé started wearing a single feather in her ear, and suddenly it became a global trend. That's essentially what happened with Julie. In human societies, fashion serves as a social glue, signaling belonging or rebellion. For chimps, this could function similarly, reinforcing group cohesion in a sanctuary setting where natural hierarchies might be disrupted. The Chimfunshi sanctuary houses orphaned and rescued chimps, so their behaviors might be influenced by this artificial environment, but the researchers argue that the trend's emergence and spread are organic.

Skeptics might wonder if this is truly "fashion" or just mimicry. After all, animals like birds decorate nests, and dolphins have been seen carrying sponges not just for tools but possibly for play. But the key difference here is the social learning and persistence without utility. Van Leeuwen's team ruled out environmental factors by noting that grass was equally available to all groups, yet only Julie's adopted the ear-wearing. They also observed that the chimps adjusted the grass repeatedly, suggesting it was intentional rather than accidental.

The implications extend beyond chimpanzees. If such trends can arise in apes, it prompts questions about the origins of human culture. Did our early ancestors start with similar arbitrary behaviors – a leaf in the hair, a shell necklace – that evolved into complex symbolic systems? This study underscores the continuum between animal and human minds, blurring lines we once thought sharp.

As research continues, scientists hope to track if the trend evolves or fades. Will new generations of chimps in the group keep it up? Could it spread to other groups through inter-troop interactions? For now, the grass earring remains a charming reminder that innovation and style aren't human monopolies. In the world of chimpanzees, fashion is alive and well – one blade of grass at a time.

This phenomenon not only enriches our understanding of primate behavior but also invites us to reflect on our own trends. Next time you see someone sporting the latest accessory, remember Julie and her troop: sometimes, the weirdest ideas catch on, binding us in unexpected ways. (Word count: 1,048)

Read the Full New Atlas Article at:
[ https://newatlas.com/biology/wearing-what-where-chimps-start-the-weirdest-fashion-trend/ ]

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Wearing WHAT Where?! Chimps start the weirdest fashion trend

Chimps' Bizarre Fashion Fad: Grass Earrings Spark a Cultural Phenomenon in the Wild