Armies march. Congregations sway. Crowds chant the same words at the same beat. Cultures separated by oceans all invented ways to move in unison, which is a strong hint that the behavior does something.
Scott Wiltermuth and Chip Heath tested it. In three experiments published in Psychological Science in 2009, they had people walk in step, sing together, or move in time, then measured how they behaved in group economic games afterward. People who had acted in synchrony cooperated more — and kept cooperating even when it cost them personally.
The counterintuitive detail: the cooperation did not depend on everyone feeling happy. Synchrony boosted cooperation whether or not it lifted people's mood. Something about matching your body to a group's rhythm shifts how you treat that group, underneath conscious feeling.
This is one answer to an old problem: how do you get people to sacrifice for a group instead of free-riding on it? Institutions that need collective effort — armies, faiths, movements — landed on synchronized ritual long before anyone could measure why.
The caveat: these were short lab studies, not proof that a drum circle fixes a fractured community. Synchrony is a nudge, not a cure.
For culture builders, the practical read is that form carries function. A gospel choir, a second-line parade, a room clapping on the two and four — these are not just aesthetic choices. They are cooperation technology, and they work whether or not the room is in a good mood.
Sources
Wiltermuth, S. S., & Heath, C. (2009). "Synchrony and Cooperation." Psychological Science, 20(1), 1–5.