The Tanganyika laughter epidemic of 1962 was an outbreak of mass psychogenic illness rumored to have occurred in the vicinity of the village of Kashasha on the western coast of Lake Victoria in the modern nation of Tanzania near the border of Kenya. It is possible that, at the start of the incident, a joke was told in a boarding school, and that this joke triggered a small group of students to start laughing. The laughter perpetuated itself, far transcending its original cause.
The epidemic is often understood as implying that thousands of people were continuously laughing for months. However, since it is physiologically impossible to laugh for much more than a few minutes at a time, the laughter must have made itself known no more than sporadically. The epidemic reportedly consisted of occasional attacks of laughter among groups of people, occurring throughout the vicinity of the village of Kashasha at irregular intervals. According to reports, the laughter was incapacitating when it struck.
The school from which the epidemic sprang was shut down, but the children and parents transmitted the laughter to the surrounding areas. Other schools, Kashasha itself, and another village, comprising thousands of people, were all affected to some degree. Six to eighteen months after it started, the phenomenon died off. Other symptoms were reported on an equally massive scale as the reports of the laughter itself, such as, fainting, respiratory problems, rashes, and attacks of crying.
There are only a few reports of this occurrence. These reports have been embellished and misquoted. In cases of mass psychogenic illness there are often not many reports of the incident. Due to its nature the incident has been confused with positive humorous or infectious laughter as seen in phenomena like the holy laughter movement. The nature of mass psychogenic illness, however, is quite dissimilar to these euphoric experiences.