It’s the dance craze of 2013. Sort of. Miley Cyrus does it/did it way back in March (and later at the VMAs), prompting Jay Z to tweet “worst nightmare.” A few months later, 33 San Diego students were suspended for twerking at Scripps Ranch High School and then uploading the video, although the punishment was later reduced. YouTube has more than 2 million twerking posts, much of it NSFW. So, OZY triber Breed launched an investigation: Just how old should you be to shake, wobble and jiggle like that?