Apparently, chimpanzees make fashion statements, that others openly imitate, and actively prefer listening to music from Africa and India.
Two recent studies have revealed that chimpanzee culture is not only much deeper and richer than we once believed but that it is evolving as well.
Grass Earrings Are In
Julie, a chimpanzee living at the Chimfunshi Wildlife Orphanage Trust in Zambia, Africa, was the trendsetter. Researchers saw her first “wearing” a blade of grass in her ear in 2010. Scientists from the Max Planck Institute soon observed others in Julia’s group “spontaneously adopting this seemingly non-adaptive behavior” and, thus, witnessing the emergence of a new aspect of localized chimpanzee culture.
“The chimps would pick a piece of grass, sometimes fiddle around with it as to make the piece more to their liking, and not until then try and stick it in their ear with one hand,” said lead author Edwin van Leeuwen. “Most of the time, the chimps let the grass hanging out of their ear during subsequent behavior like grooming and playing, sometimes for quite prolonged times. As you can imagine, this looks pretty funny.”
Over a year, the scientists observed eight out of the 12 group members copying Julia’s grass-in-the-ear fashion statement. The scientists witnessed this behavior only once in the three neighboring chimpanzee groups. Amazingly, several of the chimpanzees continued putting grass blades in their ears even after Julia had died.
The scientists concluded, “Natural observations like the ones described in the present report are important because they show that social learning occurs spontaneously amongst chimpanzees…Regardless of the precise mechanism underlying the behavioral diffusion, our observations importantly show that chimpanzees spontaneously copy arbitrary behavior from their group members. The fact that these behaviors can be arbitrary and outlast the originator speaks to the cultural potential of chimpanzees.”
Music to Their Ears
While some chimpanzee’s favorite fashion choice is to wear grass “earrings,” another study, published in the American Psychological Association’s Journal of Experimental Psychology: Animal Learning and Cognition, reveals their music inclinations lean toward songs with a certain beat.
“Our objective was not to find a preference for different cultures’ music. We used cultural music from Africa, India, and Japan to pinpoint specific acoustic properties,” said study co-author Frans de Waal, Ph.D., of Emory University. “Past research has focused only on Western music and has not addressed the very different acoustic features of non-Western music. While nonhuman primates have previously indicated a preference among music choices, they have consistently chosen silence over the types of music previously tested.”
The chimpanzees would spend much more time closer to the stereos when the African and Indian music was played.The scientists studied sixteen adult chimpanzees living in two groups at the Yerkes National Primate Research Center at Emory University.* They set up portable stereos at both ends of the outdoor enclosure and gave the two groups the opportunity to listen to African, Indian or Japanese music through one stereo, or silence through the other.
“Chimpanzees displaying a preference for music over silence is compelling evidence that our shared evolutionary histories may include favoring sounds outside of both humans’ and chimpanzees’ immediate survival cues,” said lead author Morgan Mingle, BA, of Emory and Southwestern University in Austin. “Our study highlights the importance of sampling across the gamut of human music to potentially identify features that could have a shared evolutionary root.”
A Dislike for Western and Japanese Music
The scientists found that when they played African and Indian music, the chimpanzees would spend much more time closer to the stereos; whereas, when they played Japanese music, the chimpanzees would move to spots where it was harder to hear the music or where they couldn’t even hear it at all. (Previous studies have shown that chimpanzees prefer silence to Western music.)
In terms of rhythmic qualities, African and Indian music are similar in having extremes in strong and weak beats. Japanese and Western music have a continuous, strong regular beat. And this rhythm pattern, according to the researchers, closely mimics threatening language patterns of chimpanzees.
“Chimpanzees may perceive the strong, predictable rhythmic patterns as threatening, as chimpanzee dominance displays commonly incorporate repeated rhythmic sounds such as stomping, clapping and banging objects,” said de Waal.
Whether it’s putting grass in their ears or having musical preferences, one thing is certain: both of these recent experiments directly point toward chimpanzee culture not only existing but evolving.
Note: The Nonhuman Rights Project does not endorse experimentation on captive animals. However, we do quote the results of these experiments when they help make the case that the animals have a level of sentience, self-awareness, and, in some cases, a theory of mind that demonstrates that we should not keep them in captivity in the first place.