Putting Your Right Knee Forward


Researchers investigated what attracts straight women to guys on the dance floor:

[W]omen rated dancers higher when they showed larger and more variable movements of the head, neck and torso. Speed of leg movements mattered too, particularly bending and twisting of the right knee. In what might be bad news for the 20% of the population who is left-footed, left knee movement didn’t seem to matter. In fact, certain left-legged movements had a small negative correlation with dancing ability, meaning that dancers who favored left leg motion were rated more poorly. While not statistically significant, these findings suggest that there might be something to that old adage about “two left feet” after all. One final surprise – arm movement didn’t correlate with perceived dancing ability in any significant way.

Going beyond the dance floor, these findings could demonstrate that mens’ dance moves could carry “honest signals of traits such as health, fitness, genetic quality and developmental history,” although the authors stress that more research is needed to be sure. It would be particularly instructive to see whether similar findings hold true for mens’ assessments of womens’ dancing ability.

Update from a reader:

The Washington Post summary of the “putting your right knee forward’ article gets a couple of things pretty badly wrong.

Yes, the variability and speed in neck and trunk movement predict dance ratings but the implication that arm movement does not predict dance ratings is simply wrong. Arm movement amplitude, variability, and speed are correlated r= .45, r=.44 and r=.34 respectively with ratings of dancing quality. These would typically be interpreted as moderately strong effects and are only “non-significant” because the original study was based on so few individuals and because the authors chose to interpret these effects using a statistical significance standard that is largely arbitrary and highly limited for such a small sample. Men wishing to impress women on the dance floor should not, however, conclude that arm movement does not matter because it matters almost exactly as much the movement speed of your legs (r= .47). Even some of the left leg movement indicators are pretty decent predictors of ratings of dance quality. Left hip twisting and left knee bending, for example, both correlate r = .31 with ratings of dance quality while left knee twisting correlates r= .34 with dance quality ratings – all moderately large effects.

The authors of the original paper also share some blame for using a statistical method (stepwise regression) that is pretty awful for analyzing this kind of data. The take-home message should be that straight men wishing to impress women on the dance floor should definitely vigorously move their trunk, neck, arms, and both legs – not just their trunk, neck and right leg.