[University of Oxford psychologist Robin Dunbar] and his colleagues report people who have just been playing music have a higher tolerance for pain—an indication their bodies are producing endorphins, which are sometimes referred to as natural opiates. In their experiments, simply listening to music did not produce this positive effect. “We conclude that it is the active performance of music that generates the endorphin high, not the music itself,” the researchers write in the online journal Evolutionary Psychology.

Dunbar argues that music evolved, at least in part, as a way of strengthening societal bonds. As a 2010 study of preschoolers found, people who sing or move in rhythmic unison tend to work together more cooperatively afterwards. This explains the presence of music in church services and military ceremonies. But what’s the trigger of this spirit of community? This new research suggests it may be the release of endorphins.