On January 30, 1962, three girls at a boarding school in Kashasha in what is now Tanzania started laughing.
They could not stop.
The laughter spread. Within days dozens of students at the school were affected. The laughter was uncontrollable and it did not stop after a few minutes or a few hours. It went on for days. Students who were overcome by the laughter also experienced crying, fainting, rashes, and pain.
The school closed on March 18 after 95 of its 159 students had been affected. But that was not the end of it.
How Far It Spread
When the students were sent home to their villages, the laughter went with them. It spread to the communities where those students lived. Other schools in the region were affected. More villages were impacted.
By the time the epidemic finally died down several months later, hundreds of people across multiple communities had been affected. Some individuals experienced symptoms for weeks at a time.
The affected people were not laughing because something was funny. The laughter was involuntary and distressing. People described it as painful. They could not eat or sleep properly while the episodes were happening. Some people had to be restrained during the worst episodes.
What Caused It
No physical cause was ever identified. Doctors who investigated found no infectious agent, no contaminated food source, and no environmental factor that could explain the outbreak.
The scientific consensus is that the Tanganyika Laughter Epidemic was a case of mass psychogenic illness. The same phenomenon that likely caused the Dancing Plague of 1518 that we covered in an earlier post. A real physical response spreading through a community through psychological and social mechanisms rather than biological infection.
The school in Kashasha had opened recently and students were reportedly under significant stress. The political situation in Tanganyika was also tense. The country was approaching independence from British colonial rule, which happened in December 1961. The social pressure on communities during that period was real and significant.
Mass psychogenic illness tends to occur in communities under stress. The physical symptoms, whether laughter or dancing or illness, are real even though they do not have a traditional biological cause.
Why This Story Matters
The Tanganyika Laughter Epidemic is genuinely strange. It is hard to describe without it sounding made up. But it is fully documented by physicians, government officials, and researchers who investigated at the time.
It is also an important piece of evidence about how human beings respond to extreme social stress. We are social creatures in ways that go deeper than we usually acknowledge. What happens in our communities affects our bodies in ways that science is still working to fully understand.
The laughter epidemic of 1962 is one of the most dramatic demonstrations of that we have on record. And almost nobody knows it happened.
Robert Lee Beers III is a writer and digital preservation advocate based in North Charleston South Carolina.
