In the qualifying matches for the FIFA World Cup of 1970, Honduras won the first match in its capital Tegucigalpa, and El Salvador won the second in San Salvador. Violence broke out at both matches between the visiting and home fans, and thousands of Salvadorans left Honduras after their victory in the second match, avoiding persecution. At the time, there were historical tensions between Honduras and El Salvador that escalated within the matches.
This soccer war isn’t the only example of an extreme reaction from fans. Hooligans, ultras or barras bravas — terms used to describe football fan associations in Latin America — often commit violence, property damage and even murder in supposed support of their teams on the field.
Francisco Zamorano, a medical biologist at the University of San Sebastian in Conception, Chile and the Clinica Alemana, wanted to understand why some fans experienced these extreme reactions, and discovered it has a lot to do with the brain.