‘Wave’ Study May Help With Crowd Control

A “wave” of 50,000 sports fans that sweeps around a stadium may be sparked by only 25 people, according to a study in Thursday’s issue of Nature. Sometimes called the Mexican wave because of its popularization in Mexico City during the 1986 World Cup soccer tournament, the action begins when fans stand and raise their arms in succession, then quickly drop their arms as they sit down. The surge of movement generally rolls across the crowd until it completes the circle at least once.

Researchers applied the same mathematical formulas used to gauge the spread of forest fires to analyze how behaviors are amplified in large crowds, said Tamas Vicsek, the lead researcher and a physicist at the University of Budapest in Hungary. The study’s suggestion that a few fans’ enthusiasm sways tens of thousands of people may be used for crowd control, the researchers said.

“In violent street incidents associated with demonstrations or sporting events, it is essential to understand the conditions under which small groups can gain control of the crowd,” Vicsek and his colleagues said.

The researchers studied tapes of waves at 14 stadiums designed to hold 50,000 or more people. A wave usually rolls clockwise at about 20 seats per second. At any given time, about 15 rows wide of people are standing.