IN DEPTH: Got Rhythm? Animals Do Too

Nov. 13, 2006 — Music has the power to affect humans physically and emotionally, and now several new studies suggest it can have similar effects on other animals, from fish to monkeys.

For example, non-human primates seem to prefer the relaxing strains of a lullaby over fast dance tunes, according to a forthcoming study in the journal Cognition that looked at the musical preferences of cotton-top tamarinds and marmosets.

Josh McDermott, a researcher in the Perceptual Science Group at the Massachusetts Institute of Technology, and colleague Marc Hauser of Harvard University placed speakers near food-baited branches. Whenever the small monkeys plopped themselves on a branch, the researchers would play music out of the speakers.

During various experiments, the scientists played a Russian folk lullaby performed on a flute, a rendition of the Mozart string concerto K458 in B flat major, a lullaby performed by a German singer or a fast techno track by Alec Empire called "Nobody Gets Out Alive."

Repeatedly, the monkeys gravitated towards the branches next to speakers playing the slowest tempo tunes, which were usually the lullabies.

McDermott told Discovery News that the animals' preferences might have something to do with the extent to which the music was arousing.

"Stressful events in the natural environment, such as fights and storms, often are characterized by rapid sequences of acoustic events, and the monkeys and other animals may have evolved an arousal response to fast events because of this," he explained.

While monkeys may find up tempo music unsettling, many people enjoy a good beat, as is evident at any dance club on a weekend night. But other research conducted by McDermott indicates human babies, like the primates, appear to have an innate fondness for lullabies. It could be that fast music may be an acquired, adult taste.

Fish Respond to Mozart

Studies on the growth and physiology of the common carp suggest that music can also be directly linked to animal health.

Sofronios Papoutsoglou, a professor in the Department of Applied Hydrobiology at the Agricultural University of Athens, and his team reared the fish in a recirculating water system under constant darkness or normal light conditions. The researchers then transmitted classical music underwater to some of the carp.

They found that darkness tended to stunt the fish’s growth, but when the carp were exposed to 30 minutes or more of Mozart’s "Eine Kleine Nacht Musik," even the light-limited carp grew at more normal rates.

The researchers also determined that classical music exposure improved liver fatty acid composition in the fish and appeared to reduce brain neurotransmitter levels associated with stressful conditions.

The scientists, who will publish their results in the January 2007 issue of Aquacultural Engineering, suggest music in future could be used to improve "fish welfare" under intensive fish farming practices.

Animal Drummers

Fish can’t drum, but over the past three decades, researchers have discovered that numerous other animals, including palm cockatoos, woodpeckers and kangaroo rats all know how to tap a beat.

University of Cambridge researcher John Bispham says the behavior involves "drumming on hollow objects in their environment in communicative, territorial or mate attraction contexts."

Perhaps most striking is the two-handed bongo-style drumming observed in gorillas and bonobos. Jane Goodall determined that chimpanzees also drum. The primatologist found that dominant chimp males usually perform such drumming "solos" while emitting vocal "pant-hoot" sounds.

In an upcoming Journal of Music Perception study, Bispham indicates that drumming in non-human primates has been correlated with resting periods, along with possibly communicating future group foraging destinations. The primate drumming is "both individually and culturally distinct," he believes.

It’s then possible, he says, that early tribal drumming by humans could have evolved from the percussive skills of our distant ape ancestors.

The Music-Language Link

Just as new findings are challenging the notion that music appreciation is an exclusive trait of humans, the idea that language is primarily a human skill has also been under fire. And many scientists see the two as being closely related.

In whales, for example, research has found an intricate relationship between music and language. The songs of humpback whales were recently determined to contain striking elements of human language.

Ryuji Suzuki, of the Howard Hughes Medical Institute at the Massachusetts Institute of Technology, and colleagues found that both humans and whales communicate by using discrete sound units that are arranged within a hierarchical structure.

While humans arrange such structures in their language, whales communicate them through songs.

University of St. Andrews psychologist W. Tecumseh Fitch agrees there is an overlap between the basic design of music— including animal songs—and language, but he thinks it is more structural, and less semantic, in nature.

In a study published earlier this year in Cognition, Fitch pointed out that human vocalizations may have developed according to acoustic and emotional foundations that are shared with other primates and mammals.

Still, he says, we humans evolved along our own, unique evolutionary course that heightened our instrumental and singing skills, as well as our appreciation of music.

McDermott agrees, adding that something must have happened in the course of evolution to make us such music lovers.

"The fact that (this level of appreciation) is unique to humans is consistent with the idea that music served some important function that drove its evolution," he said.