Bopping to the beat is a rare feat in animals, scientists find
Dogs may bark to music and chimps may bang on drums, but creatures that can truly keep a beat are rare, raising intriguing questions about the evolution of the human brain.
A bonobo named Kanzi first surprised researcher Patricia Gray more than a decade ago, when Gray was absent-mindedly tapping on a glass window and the great ape on the other side tapped back.
Startled, Gray decided to speed up the tapping and the Kanzi kept pace, even reclining on his back to tap with his toes when treated to a sprig of green onions for a snack.
"So I thought we should be taking a look here at temporal dynamics as a way of getting to some very interesting questions," said Gray.
Since then, a few other creatures have showed scientists that they can truly synchronise their movements to a musical beat - among them a cockatoo that is moved by listening to the Backstreet Boys and a sea lion named Ronan whose favourite song turns out to be the Earth, Wind and Fire classic Boogie Wonderland.
While circus animals may appear to dance or sway to pop music blaring from speakers, most of the time they are not truly synching their movements to the beat, researchers told an American Association for the Advancement of Science meeting.
"Is it just something that we and a couple of other species do?" asked Aniruddh Patel, professor in the department of psychology at Tufts University, near Boston.
"This is an important question," said Patel, whose research paper in the journal PLoS Biology is entitled "The evolutionary biology of musical rhythm: was Darwin wrong?" Charles Darwin believed that all creatures perceived and enjoyed musical cadences, and that rhythm was likely common to all animals, but that its expression depended on how complex they were.
But as scientists look more closely at true beat-keeping, and learn more about the relationship between rhythm and other abilities such as language, some believe Darwin may have been mistaken.
"In terms of cognition, in humans the ability to move to a beat seems to be related to other cognitive capacities," Patel said.
The bonobos Gray worked with were able to understand rhythm and timing, and after being given drums of their own they were soon jamming with the likes of Peter Gabriel.
The apes liked to beat the drums, but are not as precise in their tempo as the cockatoo.
"Maybe we ought to think of bonobos more like human children than human adults," said scientist Edward Large, of the University of Connecticut.
"Infants will move more to the music than to speech but they don't synchronise. As children get older, to the ages of two, three, four, they still don't synchronise," he added.
When toddlers get closest to truly keeping a beat is when they are in a playgroup with other people, studies have shown.
"They really do best in the context of a social interaction," Large said.