Scientists Make Sweet Monkey Music
TUESDAY Sept. 1, 2009 -- Monkeys prefer silence to Mozart, but new research suggests they can appreciate music inspired by the sounds they themselves make.
When researchers played music similar to soothing monkey calls, the animals moved less often. If they played music that sounded like monkey distress calls, they became anxious.
This may not sound surprising. But it shows that "communicating emotionally through music is something we can do to communicate to other species as well," said study co-author Charles Snowdon, a professor of psychology at the University of Wisconsin-Madison.
The study authors also speculate that music may have had its origins in animal calls.
Non-human primates don't seem to appreciate human music, Snowdon said, although research has suggested they prefer Mozart to rock music and silence to Mozart.
In the new study, University of Maryland cello player David Teie created brief snippets of music that were inspired by the calls of the cotton-top tamarin, a very vocal species found in the rainforests of South America. The music included similar pitches, and sounds were of similar lengths.
Then Snowdon played the snippets for monkeys of that species to see if they could tell the difference between music inspired by soothing calls and calls that communicate fear and threats.
The findings appear in this week's issue of Biology Letters.
The researchers found that the monkeys could indeed tell the difference between the two different types of music and acted accordingly, becoming calm or agitated.
Human ears can also detect the differences between the types of monkey music: calming music has longer tones, while the agitating music is more staccato.
By contrast, the monkeys were indifferent when the researchers played calming and arousing music designed for humans, Snowdon said.
Humans also use short, staccato notes to arouse themselves, Snowdon said, and longer notes for calming purposes. You might tell a baby to calm down, for example, by saying "Aww, come on, come on," starting at a high pitch and descending, he said.
Frans B.M. de Waal, a professor of psychology at Emory University who studies primates, said the findings appear to say more about how monkeys respond to the sounds they make than they do about music or the evolution of music.
As to the idea that staccato sounds are perceived as more aggressive than softer sounds in both humans and the monkeys, de Waal said that may be the case in humans because lullaby-like music sounds similar to a mother's cooing voice.
Snowdon no longer has a monkey colony to use in his research. But he said his co-author, Teie, is exploring the concept of music for cats.
"If we understand how we can affect their emotional states through using musical tones and aspects of our speech, maybe those of us living with companion animals can have a better relationship with them, too," Snowdon said.
Visit the University of Wisconsin to hear the monkey music.
Posted: September 2009