Excerpted from "Humoring the Gerontologists," from the website www.damninteresting.com:
... In the small village of Kashasha, Tanganyika (modern Tanzania), students at a girls' boarding school began to laugh following some remark or event which is now lost to history. ... The laughter was abnormallly infectious, and soon the greater part of the student body was incapacitated with the convulsions. In an effort to quell the outbreak, administrators closed the school and sent the students home, but this allowed the epidemic to spread ... (it) propagated to thousands of people, including other schools, workplaces a neighboring village. The episodes became unpleasant for the sufferers, leading to abdominal pain, fainting, respiratory problems, rashes and uncomfortable weeping. ... Reports vary regarding the duration of the epidemic -- anywhere from six to eighteen months -- but over time it faded. ... Most historians and scientists attribute the bizarre incident to mass hysteria (specifically, mass psychogenic illness). The nation had won its independence from Great Britain only months prior, and the resulting increase in expectations among the citizenry was said to have produced unusually high levels of stress.
* "An epidemic of laughing in the Bukoba district of Tanganyika" (from Central African Journal of Medicine, May 1963): @
* "Examining 1962's 'laughter epidemic' " (Chicago Tribune, July 2003): @
* "Contagious Laughter" (2008 broadcast from radiolab.org): @