So the researchers set up an experiment as follows: they recruited 30 men to dance to a core drum beat for 30 seconds. The dancers were given no specific instructions on how to dance beforehand, and their movements were recorded via a sophisticated motion-capture system. Each dancer's 30-second routine was then used to animate a "featureless, gender-neutral" computer-generated avatar. Researchers asked 37 women to view each of the dancing avatars and rate their performance on a seven-point scale.
For a sense of exactly what these avatars looked like, check out the videos below. The first shows the avatar of a dancer rated highly in the study, while the second shows a "bad" dancer.
The difference between the two should be obvious, perhaps painfully so. But how exactly do you quantify what's going on in each video? The researchers developed a taxonomy of individual dance moves. They isolated three key body regions and the main joints within - the central body, including neck and torso; legs, including knees, hips and ankles; and arms, including shoulders, elbows and wrists. For each dancer, they then measured the degree and type of movement at each joint - speed, size, and variety of movements like bending, twisting and tilting.
They found that women 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.
Originally published on March 25, 2014