How a Single Blade of Grass Turned into a New Fashion Trend

Chimpanzee Fashion Trend

Story at-a-glance -

  • Researchers watched over 700 hours of video footage of 94 chimpanzees to understand how one chimpanzee who decided to put a piece of grass in her ear sparked an enduring fashion trend among her friends
  • For no apparent reason, the chimp, named Julie, began putting a stiff blade of grass in one or both ears. She wore it while she groomed, played, and napped. Before long, others in her group were also adorning themselves with grass-in-the-ear
  • Study results suggest that when the other chimps copied Julie’s ear decoration, it was spontaneous, intentional, and enduring. These results speak to the cultural potential of chimpanzees

By Dr. Becker

I’m sure you’ve heard the old expression, “Monkey see, monkey do.” Primates are indeed mimics, and new research suggests that as they copy one another, they create new traditions within their own groups.

And now a team of scientists has answered the question of how one chimpanzee placed a piece of grass in her ear and became a fashion trendsetter. Their findings were published in the journal Animal Cognition1 late last year.

Julie the Chimp Sparks a New Fashion Trend

Five years ago, lead study author Edwin van Leeuwen of the Max Planck Institute for Psycholinguistics in The Netherlands, witnessed first-hand that a chimp named Julie liked to put a stiff blade of grass in one or both of her ears. There was no apparent reason for the adornment, but she left it there while she groomed, played and snoozed at the Chimfunshi Wildlife Orphanage Trust sanctuary in Zambia.

In future visits to the sanctuary, van Leeuwen noted that other chimpanzees in Julie’s group were also sporting blades of grass in their ears. He was intrigued and set out to discover if the other chimps were copying Julie using what is known as social learning.

Julie’s Friends Pick Up on Her Fabulous Grass-in-the-Ear Creation

The research team collected and evaluated several hundred hours of video filmed over the course of a year. The footage captured the activities of 94 chimpanzees living in four separate social groups inside the sanctuary. Only two of the groups could see one another.

The team discovered that chimps in only one of the four groups regularly bedazzled themselves with grass-in-the-ear. In one other group, one monkey did it just once. But in Julie’s group, 8 of the 12 chimpanzees repeatedly did so. First there was her son Jack, then Kathy, Miracle and Val, all of whom spent a lot of time with Julie. At least two chimps wore grass-in-the-ear at the same time. Kathy and Val even continued the behavior after Julie died.

Study Results Speak to the Cultural Potential of Chimpanzees

According to the researchers, their study results suggest the grass-in-the-ear behavior is intentional, and certainly not coincidental. The chimps spontaneously copied the random behavior of another member of their group. And the animals who enjoyed making a grass-in-the-ear fashion statement continued to adorn themselves on their own, and even after the creator of the look was no longer around.

According to van Leeuwen:

“This reflects chimpanzees' proclivity to actively investigate and learn from group members' behaviors in order to obtain biologically relevant information. The fact that these behaviors can be arbitrary and outlast the originator speaks to the cultural potential of chimpanzees."