A consistent tendency for pedestrians to walk in a counterclockwise direction has been documented across multiple experiments in Spain and Japan.
The Hidden Bias in Human Movement
A series of experiments conducted in Spain and Japan has revealed a striking and consistent behavioral pattern: pedestrians, whether alone or in groups, tend to walk in a counterclockwise (CCW) direction. This bias appears to be universal, independent of crowd size, handedness, footedness, eye dominance, and cultural social norms.
Confined Space Experiments (Spain & Japan)
Researchers observed groups of 16, 24, and 32 participants walking freely in a circular arena with a radius of 5 meters.
Spain: In all trials, the mean collective polarization—a measure where positive values indicate CCW rotation—was approximately 0.2. The proportion of right-turners in the group did not significantly influence the bias. Probability density functions showed a peak near 0.25, with the distribution narrowing as crowd size increased. The CCW motion was more pronounced near the arena boundaries.
Japan: When the experiment was replicated with participants who typically step left to avoid collisions, the results mirrored the Spanish data. The mean collective polarization was positive in all but one trial, where it was approximately zero. Probability density functions were skewed positive, peaking near 0.2, and again narrowed with larger group sizes.
Boundary-Free & Nursery School Experiments
In an open schoolyard without defined boundaries, over 100 teenagers still exhibited a positive mean polarization, confirming the CCW bias persists even in unbounded spaces.
Boundary-Free Experiment (Spain): Over 100 teenagers walked in a 50-meter by 60-meter open schoolyard. The mean collective polarization remained positive, and the probability density function was narrower than in the confined arena, consistent with the larger crowd size.
Nursery School Experiment (Japan): Children approximately 5 years old ran freely in an enclosed space. The mean collective polarization exceeded 0.7 in all trials, with probability density functions peaking near 1—indicating near-unanimous CCW rotation.
Individual Behavior & Biological Roots
Researchers analyzed individual polarization across all scenarios. The distribution showed a larger peak at approximately +1 (CCW motion) than at -1 (clockwise motion). Notably, the group-level patterns could be reproduced by randomly sampling individual values from solitary walking data, suggesting the bias originates from individual behavior.
In a separate experiment, over 200 participants walked alone in an enclosed arena. A two-tailed one-sample Wilcoxon signed-rank test confirmed a statistically significant positive individual polarization (median 0.12–0.27, P < 0.001). No statistically significant differences were found between subgroups based on handedness, footedness, eye dominance, sex, or right-eye patching.
Social Norms vs. Observed Behavior
A survey of 168 participants in Spain asked about the expected direction of rotation in a circular arena. No clear norm emerged. The majority of aligned expectations pointed toward clockwise (CW) rotation—directly contrary to the observed counterclockwise behavior.
The experimental evidence contradicts explicit social expectations, as most participants anticipated a clockwise bias.
Conclusion: An Unresolved Mystery
The study concludes that the counterclockwise motion bias is a consistent individual-level phenomenon. It is not explained by pedestrian-wall interactions, pedestrian-pedestrian avoidance, explicit social norms, handedness, footedness, eye dominance, or cultural background. The source of the bias remains undetermined but is hypothesized to have a fundamental, possibly biological, origin.