Put a small crowd of people in an open space and ask them to walk around, and something odd happens. They do not move as randomly as you might think. Again and again, in experiments in Spain and Japan, groups of pedestrians began drifting counterclockwise, as if an invisible current had started to pull them around the room. The effect was consistent time and time again. In one early set of trials, 32 out of 33 groups showed the same counterclockwise tendency. “When analyzing the experiments, my colleagues realized by chance that in 32 out of 33 experimental trials, as people moved and turned, they noticeably preferred to turn counterclockwise,” said Claudio Feliciani, a project associate professor at the University of Tokyo. It seems like humans may have a small but persistent turning bias in the way they walk. The researchers tested whether culture, gender, handedness, footedness, eye dominance, crowd size or walls could explain it. Most did not. A Crowd Pattern that Starts with the Individual Scientists who study crowds have long known that pedestrians self-organize. On a sidewalk or in a station corridor, people do not usually collide at random. They read one another’s motion, adjust their steps...

New experiments suggest humans have a hidden counterclockwise bias.