Science is confirming what many women on the dance floor already seem to know: that shaking their hips is, well, hot. Researchers are following up on a 2011 study that asked women to rate top dance moves among men (it's all about neck and torso fluidity). Reporting in the journal Scientific Reports, they found that at least among the 200 viewers of 39 young women's dance moves, lots of hip movement and asymmetrical arm and leg movements got the highest ratings. From an evolutionary standpoint, the hips aren't surprising, one of the researchers tells Scientific American, because fluidity here may signal a woman's fitness and even reproductive health.
But most (143) of the 200 viewers doing the rating were female, hinting at the potential for dance moves to also be a competitive display of skill, reports the New York Times. "They’re showing off how good they are to female rivals," says the researcher. Another researcher not involved in this study suggests that dance moves can also be a display of "affiliation, friendship or bonds to other people," where displaying confidence helps one gain not just romantic partners but also friends. The stiffness of the lowest-rated dancers, for instance, is suggestive of shyness, while the asymmetry of arm and leg movements hints at a more relaxed person. (This police officer started busting out some serious dance moves.)