In a November 2014 study, researchers at McGill University found that although most individuals have a natural sensory ability to tap along to a beat, or sway their hips to the rhythm of the music, some people (like all those guys standing on the edge of the dance floor?) just can’t. And their condition has a name: beat deafness. Here’s how it works (or doesn’t): When you clap or dance, or even walk or play an instrument, your body is using complex external signals and synchronizing your actions with them. Even if a regular, expected beat is not noticeable in a song, your body is able to process the signal and maintain a constant rhythm with it. Beat-deaf people are unable to pick up a regular beat after an interruption. The good news: it’s pretty rare, so your friends can probably be coaxed onto the dance floor.