Why Do People Tend to Walk to the Left?

Researchers in Spain were studying people’s walking patterns when they noticed something unexpected: Most of the participants in about 40 experiments spontaneously veered to the left. The researchers assumed they’d find an obvious explanation and began what they thought would be a simple investigation to determine the answer.

Five years later, they’re no closer to solving the mystery. They examined, for example, whether the tendency was related to whether someone was alone or in a crowd; whether the subject was right- or left-handed; or whether the person lived in a country where cars are driven on the left side of the road instead of the right. But none of these factors seemed to explain it. What the researchers did find was a striking tendency for people across demographics, cultures, and conditions to veer in a counterclockwise direction.

They plan to test more theories, perhaps involving animal behavior. “Fish … move in circles,” says study co-author Iker Zuriguel. “But whether they prefer rotating in one direction or the other, I don’t know.”