According to a new study published Thursday in Scientific Reports, researchers from Northumbria University in England have figured out what makes a woman a good dancer. As Shakira so famously put it: hips don't lie.
Dance is most often connected to courtship, the study's authors note, and in order to understand what messages a woman's body movements send to potential partners, it's necessary to decipher which movements are appealing.
Researchers first recruited 39 heterosexual female university students between the ages of 18 and 30 to dance however they wanted for 30 seconds to a basic drum rhythm while being recorded by a motion capture system. That footage was modified to remove any distinguishable physical features, so that people viewing the data could focus on movement alone.
Researchers then tasked 57 men and 143 women with rating the dancers on a scale of one to seven, with seven indicating the dancer was extremely good. After determining the five highest and five lowest dancers, two observers trained in the biomechanical analysis of human movement then surveyed these clips and identified which joint angles were best distinguishable among the dancers.
Ultimately, both male and female judges agreed that dancers with a wide range of hip swing, more asymmetric thigh movements, and moderately asymmetric arm movements (as in, your limbs move independently from one another) were the most attractive.
Nick Neave is an associate professor of psychology at Northumbria University and an author on the study. He says dance moves might provide cues to reproductive and health status for both women and men. A previous study he co-authored found that, for men, dance moves indicate strength and vigor. "Males are probably more showing off their size and strength to potential male rivals than they are [trying] to attract females," he tells Broadly, "but females are showing off their reproductive and health qualities by moving their hips. Hip movements are a key feature of female movements, and the more feminine you are, the larger and more expressive your hip movements."
Furthermore, the study points out, previous research has suggested that a woman's body movements can indicate how fertile she is.
As for why asymmetric arm and thigh movement is so appealing, consider how hard it is to pat your head and rub your stomach at the same time. It's more challenging to move your limbs in different directions, the study points out, so being able to do so might "attest to high-quality motor control" and thus be more attractive.
Apart from perhaps making women all over the world a little more self-conscious when they hit the dance floor tonight, Neave says his research is working "to uncover the scientific basis of how movements can signal reproductive quality and how these movements can be interpreted."
But if you're uncomfortable with your body movements sharing details about your ovulation cycle, practicing your dance moves can help—some. "It is very likely that the unconscious signals can be altered by better training, focusing attention onto certain movements and gestures," Neave says, "but this can only take you so far. The hip movements, for example, are limited by your physique and biomechanics."
He continues: "Dance is not all about showing off your moves to a potential partner or rival. Dance is a key human social behavior which is related to social bonding—it is all about expressing yourself and having fun!"