Okay, I'll admit it - occasionally I indulge in some guilty pleasures like watching the show Dancing With the Stars and of course, I have some commentary on it from the vantage point of evolutionary psychology. The show, for those who don't know, centers on several "celebrities" who get paired with a professional ballroom dancer to learn and then perform dances like the mambo, two step, and tango in front of a panel of professional judges. Each week brings two new dances and a rejection for those who don't measure up. The audience gets to weigh in on the decision. The show became so insanely popular last year that it was brought back for a second season.
Last year in my Evolution of Human Mating class a student asked about why her boyfriend refuses to dance with her. She wanted him to take ballroom dance lessons with her. Perhaps there are millions of women who are now asking this same question and hoards of men shrugging their shoulders at the thought. But why? Because it's prissy is not a good enough reason. The men really are sexy when they dance. And we all know what dance is a metaphor for. It's insanely sexual at its core - a sexual display served up for our consumption or rejection. So why won't the average guy get on board?
The information conveyed through dance reveals a guy's fitness and most just don't measure up. The article "Dance reveals symmetry especially in young men" in Nature 2005 presents evidence that men who are rated by women as the best dancers are also more symmetrical. The right and left sides of their faces and bodies more perfectly match. In nature, symmetry is associated with greater reproductive success for numerous species, including humans. Thus, dance isn't just for fun; it reveals hidden messages about an individual's fitness - messages men may want to keep hidden.
The Dance Symmetry Project website describes the neat study methodology (they used image capture technology with body mounted light sensors), presents video of symmetrical and less symmetrical dancers, and has a link to the Nature podcast. This study counts as one of many that I think is so cool I wish I had done it!
Why symmetry is associated with dance is still a bit of a mystery. One theory holds that symmetrical organisms are more metabolically efficient and that translates into greater coordination and stamina. This would also explain why a sample of gifted track athletes were more symmetrical than less successful athletes. A quick google search revealed that in the professional running world, symmetry of stride is a major goal and source of concern if it isn't. By studying runners on a treadmill or wear patterns on shoes, physical trainers can figure out how to improve stride and reduce injuries.
Just how important symmetry is to athletic ability and the chances of wooing a mate is open to debate. Hundreds of articles have been published on the subject but one meta-analysis by A. Palmer showed a publication bias so it's hard for some to take studies like the Dance Symmetry Project seriously. Palmer's website even calls most of the neat studies from EP we discussed in my EHM class "follies." That includes the dance study project.
It's annoying. If we looked at any field of inquiry I think we'd find publication bias. Does this negate the conclusions of studies that are published? Perhaps EP gets singled out for special criticism because people don't like its political implications. People regularly get bent out of shape about discoveries that we humans function under the same rules as the rest of the animal kingdom.
Humans like watching presumably symmetrical stars dancing just like blue-footed booby birds presumably derive some pleasure from watching the fancy footwork of other boobies. Both are examples of courtship rituals backed by sound evolutionary theory and evidence.