Dance fever: Study shows it's something in the way he moves

Sure, you already may know that guys with superior moves have sex appeal. Women simply prefer men who can dance.

But did you know that it may have something to do with symmetry?

A group of Rutgers anthropologists interested in whether bodily symmetry confers a survival advantage, has turned to one of the world's oldest mating rituals for an answer -- dancing.

"We wanted to discover whether dancing ability is related to symmetry," said William Brown, a post-doctoral researcher at Rutgers in New Brunswick. "Dancing is an important part of courtship in many societies -- it could kindle romantic interest. Or at least flirtation."

Reporting in today's edition of the journal Nature, the anthropologists for the first time collaborating with University of Washington computer scientists have linked dancing ability to desirability. The best dancers, they found, have the greatest body symmetry.

The study was conducted by creating computer-animated figures that duplicated the movements of 183 Jamaican teenagers dancing to popular music.

Body symmetry often is viewed by scientists as an indicator in most animal species including humans of how well an organism develops despite problems it might encounter as it matures. It also conveys an organism's underlying quality as a potential mate.

Humans, like starfish, exhibit bilateral symmetry. If divided in half by an imaginary vertical line, one side mirrors the other.

In humans, though, there are subtle differences. One arm can be slightly longer than the other. Ears may not match.

The researchers gathered a group of teens ages 14 to 19 from Southfield, Jamaica, a rural region where music and dancing are valued. Using digital calipers to gauge the dimensions of the subjects, Brown and the team of anthropologists compared the ears, elbows, wrists, knees, ankles, feet, and third, fourth and fifth fingers, with measurements precise to three decimal places.

"At least since Darwin, scientists have suspected that dance so often plays a role in courtship because dance quality tracks with mate quality," said Lee Cronk, associate professor of anthropology. "But this has been hard to study because of the difficulty of isolating dance movements from variables, such as attractiveness, clothing and body features.

The study group was composed of men and women who were the most symmetrical and those who were the least. The researchers affixed infrared reflectors on 41 body locations of each dancer, from head-to-toe and arm-to-arm, to capture and measure detailed body movements.

The, each was asked to dance.

The subjects grooved alone to the same song -- a bouncy number popular in Jamaican youth culture -- while being videotaped. The scientists fed the data into programs that first created dancing animations of stick figures. Then, to avoid any bias introduced by subjects recognizing one another or using other cues for attractiveness, those images were converted into virtual human forms.

One animation shows an anatomical doll pathetically repeating the same few dance steps over and over, resembling the average I-can't-dance boyfriend. The young man had a low rating for bodily symmetry.

In another, the anatomical doll gyrates, pivots and swivels in familiar life-of-the -party fashion. The human behind the video had a high score for symmetry.

Women watching the recordings preferred the dances of symmetrical men. Men, in turn, also preferred dances performed by more symmetrical females.

The men's choice, however, was not as pronounced, confirming the researchers' theory that women, who usually bear the majority of the childcare burden, are more choosy when selecting a mate.

Kitta MacPherson covers science. She can be reached at 973-392-5836 or at kmacpherson@starledger.com