The Tanganyika Laughter Epidemic
Later explainedSummary
The name is wrong, and the name is most of the problem. This is not a story about people laughing uncontrollably for months, and it is not amusing.
In January 1962, three girls at a mission boarding school began having attacks of laughing and crying. It spread through the school, then through the district. Roughly a thousand people were affected, fourteen schools closed, and it ran for about eighteen months. The symptoms included crying, pain, restlessness, aimless running, fear, and occasional violence. Laughter was one symptom among several.
Two medical officers examined the affected and found nothing physically wrong with any of them. They were right, and their diagnosis has held for sixty years.
What is documented
The onset. On 30 January 1962, at a mission-run boarding school for girls in the village of Kashasha, three pupils began having attacks of uncontrollable laughing and crying. Nothing had happened to prompt it.
The spread within the school. It reached 95 of the school's 159 pupils, who were aged between twelve and eighteen. The school was closed on 18 March 1962.
It came back. The school reopened on 21 May. The outbreak resumed immediately and affected fifty-seven more pupils. The school closed again by the end of June.
The spread beyond it. It reached the village of Nshamba, where around two hundred people were affected. On 10 June it reached Ramashenye girls' middle school near Bukoba, where within eight days forty-eight of one hundred and fifty-four pupils were affected.
How it travelled, which is the diagnostic fact. Not through air, water or food. Rankin and Philip, the medical officers who investigated, established that it moved through personal contact and observation. It followed the social network of the affected. The girls from Kashasha who carried it to Ramashenye lived near that school. People saw others having attacks and then had attacks themselves.
The symptoms, in full. Attacks of laughing and crying, lasting from minutes to hours, and in severe cases recurring over as much as sixteen days. Restlessness. Aimless running. Fear responses. Occasional violence. Pain. Dilated pupils and exaggerated reflexes.
No fever. No abnormal physical findings of any kind.
The medical investigation. Rankin and Philip examined the affected and conducted lumbar punctures, virus studies and analyses of the food. They found no organic pathology. Nothing. Their report was published in the Central African Journal of Medicine in 1963, and it remains the primary source on the outbreak.
The scale. Around a thousand people affected. Fourteen schools closed. It burned out around the middle of 1963, roughly eighteen months after it began.
What the community thought. Locally it was called endwara yokusheka, the laughter disease, and akajanja, madness. Proposed causes among villagers included fallout from atomic bomb testing and poisoned maize flour. Adults were affected as well as children, including men.
Leading explanations
Mass psychogenic illness, motor variant. Established. Rankin and Philip identified it in 1963. Christian Hempelmann's subsequent analysis classified it more precisely as mass motor hysteria: a psychogenic illness whose symptoms are involuntary movements and vocalisations rather than, for example, fainting or nausea.
The conditions were all present, and they were acute.
Tanganyika had become independent in December 1961, one month before the outbreak began. The country was in the middle of a rapid and disorienting transformation of its administration and its schools. Julius Nyerere resigned as Prime Minister in January 1962, the month it started.
The pupils were adolescent girls in a strict mission boarding school, subject to an unfamiliar and rigid discipline, with expectations imposed on them that they had no permitted way of resisting or even discussing. That is a textbook setting: a population under sustained stress, unable to remove itself from the situation, with no sanctioned outlet.
Organic causes were investigated and excluded. Encephalitis has occasionally been proposed. It has to contend with the fact that the physicians on the ground looked for exactly that, with lumbar punctures and virus studies, and found nothing, and with the fact that the outbreak propagated along lines of social contact rather than lines of infection.
What the popular version gets wrong
"People laughed non-stop for months." No. Attacks came in bouts, from minutes to hours, recurring in the worst cases over as much as sixteen days, separated by periods of normality. Nobody laughed continuously for a year.
"It was an epidemic of laughter." It was an epidemic of psychogenic symptoms, of which laughing was one. The affected also cried, ran, screamed, felt pain, and in some cases became violent. Christian Hempelmann, who has studied it more closely than anyone, is on record as being irritated when humour researchers cite the Tanganyika outbreak as evidence that laughter is contagious. What was contagious was the illness. Laughter was a symptom of it.
"It's a funny story." It is not. It is a story about a district in acute distress, one month after independence, in which around a thousand people became genuinely and frighteningly unwell, fourteen schools were closed, and children were unable to stop.
The name has done the work of making it a curiosity. The medical officers who were there did not find it curious.
"Nobody knows what caused it." Two doctors diagnosed it correctly, in 1963, on the ground, with the diagnostic tools available to them, and everything learned since has confirmed them.
Current status
Later explained. The mechanism is understood, the diagnosis has stood for six decades, and the case is closed.
The registry keeps this record for the same reason it keeps the Dancing Plague of 1518, and the two should be read together. Both are outbreaks of involuntary movement in a population under severe stress with no permitted way out. Four hundred and forty-four years apart, in a Rhineland city and an East African district, the same thing happened, and it took the shape each culture gave it.
Sources
- Rankin, A. M. and Philip, P. J. (1963). "An epidemic of laughing in the Bukoba district of Tanganyika." Central African Journal of Medicine, May 1963. The primary source.
- Hempelmann, C. F. (2007). Analysis of the outbreak as a motor variant of mass psychogenic illness. Humor: International Journal of Humor Research.
- Bartholomew, R. E. (2001). Little Green Men, Meowing Nuns and Head-Hunting Panics: A Study of Mass Psychogenic Illness and Social Delusion. McFarland.
- Historical scholarship on Tanganyikan independence (December 1961) and the administrative and educational transition that followed.
Last reviewed: July 2026. Records are provisional. Where the evidence changes, the entry changes. Found an error? Tell us.