Thanks to graphic-journalists at the Washington Post and scientists in the United Kingdom, there's now a how-to-dance diagram based on evolutionary biology for the rhythmically impaired. A couple years ago, researchers at Northumbria University and the University of Gottingen wanted to better understand what makes someone a more suitable mate in the ecosystem of the dance floor. Of course, factors like facial attractiveness, body shape and fitness, style of dress and other socioeconomic giveaways, all affect how a person sizes up the dancing ability of their peers. But if these externalities could be accounted for, what actual dance moves would prove the most appealing to women? To find out, the researchers recruited 30 men to perform 30-second dances to a simple drum beat. The routines were recorded and then transposed onto a gender-neutral, computer-generated avatar. Next, the biologists had 37 women watch the dancing avatars and rate each performance. A viewing of the dancers who got the highest marks, and those who scored the lowest, made plain the differences in skill and coordination. But quantifying what made someone a better or worse dancer was difficult. Under closer analysis, the evolutionary biologists were able to determine that women preferred larger and more varying movements of the head, neck and torso. They calculated that leg movement was less important, and that arm movement had zero effect on desirability. The study was originally published in the journal Biology Letters. Below are the videos of two avatars demonstrating good (top) dancing and bad (bottom) dancing.