Sociology
The Micro-Sociology of Pedestrian Flow and Sidewalk Etiquette
Quick fact
Pedestrians in a crowd spontaneously organize into distinct traffic lanes, similar to vehicular traffic, without any central coordination or signage, often within seconds of a flow becoming congested.
Why this is interesting
You've navigated a crowded sidewalk countless times without a formal rulebook—so how does everyone seem to know the unwritten steps of this intricate dance?