"Individual small biases can sum up to produce net anticlockwise rotation in crowds."
A new study reveals a surprising and consistent human tendency: when walking without a destination, people in both Spain and Japan prefer to turn left (counterclockwise) over turning right.
The Study
Published in Nature Communications, the research was conducted by scientists from the University of Navarra and the University of Tokyo. It documents a persistent counterclockwise (left-turn) bias in pedestrians across both countries, challenging previous assumptions about cultural influences on walking behavior.
Methodology
The researchers conducted experiments in enclosed spaces and open fields in both Spain and Japan, observing individuals and crowds of varying sizes. To isolate the effect of social influence, one experiment involved 209 individuals walking alone in a hexagonal enclosure. The study also tested the effect of patching one eye. Participants ranged in age up to their mid-30s.
Key Findings
- A consistent counterclockwise (left-turn) bias was observed across all experimental conditions.
- The bias was documented in both countries, despite Japan's typical custom of left-sided dodging while walking, which would have predicted a clockwise preference.
- The bias was not explained by factors such as handedness, footedness, or eye dominance.
- The bias was present in both sexes but was observed to be stronger in children.
- The bias persisted when individuals walked alone, indicating it is not solely a result of social coordination.
- The bias remained after participants had one eye patched.
Proposed Explanations
The exact mechanism for the bias is not yet established. Researchers tested biomechanical asymmetry, cultural influences, and the Coriolis effect, but the bias persisted in all environments. The study's authors suggest the bias may originate from asymmetries at the biomechanical level rather than from social or cultural factors. Virtual reality experiments and simulations of a broken leg did not resolve the mechanism.
"The discovery was accidental during pandemic social-distancing experiments," said Dr. Iñaki Echeverría Huarte, a researcher at the University of Navarra. He noted that individual small biases can sum up to produce net anticlockwise rotation in crowds.
Significance and Applications
Researchers propose that understanding this directional bias could improve the accuracy of crowd dynamics and evacuation simulations. This information may be relevant for the design of public spaces, including airports, stadiums, and evacuation routes, as well as other crowd management strategies.
Limitations and Future Research
The study did not include participants older than their mid-30s. The researchers have indicated that future research could examine older populations, people with mobility differences, and use virtual reality to control sensory inputs. The team also plans to investigate whether a similar directional bias exists in other animals.
Additional Context
The researchers note that anticlockwise running was standardized in athletics in 1913, possibly due to right-leg dominance. A similar left-turn bias has also been observed in rock ants.