The Tanganyika Laughter Epidemic – How a Medical Crisis Became a Joke

In 1962, something spread through Tanganyika. Fourteen schools shut their doors. Over a thousand people fell ill.

Tanganyika was a British colonial territory that had gained independence just seven weeks earlier. Two years later, it would merge with Zanzibar to form what we now call Tanzania.

History remembers it as the ‘Tanganyika Laughter Epidemic’, a joke that got out of hand. But the only medical report written at the time mentions no joke. What it describes is weeping, panic, physical collapse, and fear.

The real mystery isn’t what happened. That’s written down. The real mystery is how it got turned into a story about contagious giggling.

The Story on File vs. The Story Being Told

Here is what does not add up.

Search for the Tanganyika Laughter Epidemic online and you will find dozens of articles telling the same story… schoolgirls in newly independent Tanzania started laughing after someone told a joke, could not stop, and the ‘laughter’ spread like wildfire. Some claim individuals laughed for months on end. The whole thing sounds like a Monty Python sketch that got out of hand.

But pull up the actual medical report from 1963, written by A.M. Rankin and P.J. Philip, the two doctors who investigated the outbreak, and you will find something entirely different. They make no mention of any joke. Not once. Instead, they describe the first cases as three pupils who ‘commenced to act in an abnormal manner’ on 30 January 1962.

The contradictions continue to mount.

The popular version makes for a better story. Who does not love the idea of contagious laughter bringing a country to its knees? But the evidence tells us something darker happened in Tanganyika. This was not an epidemic of mirth. It was an outbreak of distress so severe that over a thousand people experienced physical symptoms with no organic cause.

What the Doctors Actually Saw

Rankin and Philip were not writing a mystery novel. They were documenting a medical crisis. Their clinical observations paint a picture that is nothing like the popular myth.

The primary symptom was not joyful laughter. The doctors defined it as an ‘epidemic…characterised by episodes of laughing and crying’. Note that: laughing and crying. The attacks came with significant restlessness. Patients sometimes became violent when restrained. The psychological component was severe. Patients reported feelings of intense fear, including the sensation that ‘someone is running after her’ or that ‘things are moving about in their heads’.

Physical examinations revealed something else odd. No fever. Not in a single case. The only abnormalities the doctors could find were pupils that were ‘frequently more dilated than controls’ (though still reactive to light) and ‘frequently exaggerated’ tendon reflexes in the lower limbs. If this was an infection, it was unlike any the doctors had seen.

The attacks themselves followed a pattern. Sudden onset. Laughing and crying that lasted ‘a few minutes to a few hours’. Then a period of respite before the next attack. The maximum number of attacks recorded in any individual was four. The total duration of illness ranged from several hours to 16 days maximum, with an average of seven days.

Not months. Not continuous laughter. Brief episodes of mixed emotional outbursts over the course of a week or two. This was not mass hilarity. It was mass psychological breakdown.

How Investigators Ruled Out Sickness and Poison

Rankin and Philip did not jump to conclusions. They followed a methodical process of elimination, starting with the most obvious physical explanations.

First, they tested for infection. They performed lumbar punctures on 17 patients. These are spinal taps that collect cerebrospinal fluid, used to detect infections in the brain and nervous system. The results were clean. No biochemical abnormalities. No bacteria. Nothing unusual under the microscope. Blood tests were also normal. White cell counts were within healthy ranges.

They did not stop there. Blood samples from 15 active cases were packed up and sent to the Virus Research Institute in Entebbe, Uganda. The lab tried to culture viruses from the samples. Nothing grew. They tested for viral antibodies. Nothing there either. Virologically, the patients were clear.

If not a virus, maybe a toxin? The investigators looked for a common source. But the affected people had not all eaten the same food. Water supplies varied between locations. The school used sealed rainwater tanks. The villages relied on local wells and streams. No common source.

They examined maize samples from the affected areas, checking for contaminated seeds. Clean. Someone suggested datura poisoning, a plant known to cause psychological symptoms. But datura victims have dry mouths, fixed pupils, and lose muscular coordination. None of the patients showed these signs. Plus, datura poisoning resolves in hours, not days.

By the end of their investigation, Rankin and Philip had eliminated every plausible physical cause. No pathogen. No poison. No environmental factor that could explain why hundreds of people across multiple villages were having these attacks.

That left them with one remaining explanation.

The Explanation That Got Ignored

Having excluded organic causes, Rankin and Philip reached a clear diagnosis… mass hysteria spreading from person to person through direct contact. In modern terms, this is known as Mass Psychogenic Illness (MPI).

They were not throwing the term around lightly. Their report opens with this statement: ‘As the commoner epidemics are caused by the spread of viruses, bacteria or parasites, there is a tendency to forget that abnormal emotional behaviour may spread from person to person and so take on an epidemic form’.

They concluded the phenomenon was mass hysteria occurring in a ‘susceptible population’ and was likely a ‘culturally determined disease’. This was not speculation. It was a diagnosis based on the systematic elimination of alternatives.

Modern analysts agree. Christian Hempelmann, who re-examined the case decades later, classifies it as a ‘motor-variant’ of MPI. Unlike anxiety-variant MPI, which involves symptoms like fainting, motor-variant MPI manifests as physical actions, such as laughing, crying, running, and shouting.

The popular claim that ‘no official explanation was given’ is factually wrong. A clear medical diagnosis was provided by the only professionals who studied the event on-site. They identified it as a psychological contagion triggered by extreme stress.

The real question is what created that stress.

What Set It Off – A Nation at Breaking Point

The outbreak began on 30 January 1962. To understand why, you need to grasp what Tanganyika was going through at that moment.

Consider the timeline:

Just seven weeks after independence, with the country’s leader stepping down to restructure the government, these schoolgirls started their ‘abnormal behaviour’.

The newly independent nation was in chaos. Not the celebratory kind. The real kind, where nobody quite knows who is in charge or what happens next. Nyerere’s resignation was not a simple political manoeuvre. He was stepping back to transform TANU (the Tanganyika African National Union) into a mechanism for one-party rule. The colonial administrators were leaving. The new Tanganyikan civil service was struggling to fill the gaps. This created a backdrop of pervasive, nationwide anxiety.

For the students, this national upheaval coincided with a radical transformation of their educational system. The new government had moved immediately to dismantle the colonial ‘racial education’ system, which maintained separate schools for Europeans, Asians, and Africans. In its place, they created an integrated national system with new curricula, new standards, and new expectations.

Students at mission schools like Kashasha found themselves caught in what researchers call ‘cultural dissonance’, trapped between the ‘strict traditional belief systems of their family and village elders, and new ideas challenging those beliefs in school’. The academic pressure was intense. Education was seen as the path to success in the new nation, but the rules kept changing.

The region around Bukoba had its own specific pressures.

Colonial policies like hut taxes had pushed farmers into the cash crop economy, creating dependencies on fluctuating coffee prices and ironically making the area a net importer of food. There is evidence of pre-existing social tensions within the local Haya culture, particularly concerning anxieties among men over women’s morality and growing independence.

The Kashasha school itself added another layer of stress.

Contemporary accounts describe it as extremely strict. The school had architectural features designed to control the students, including windowless walls to prevent the girls from seeing men in the nearby village. This was a pressure cooker environment at the best of times. January 1962 was not the best of times.

How a School Closure Spread the Panic

For nearly two months, the outbreak stayed contained within Kashasha’s walls. By mid-March, 95 of the school’s 159 pupils had been affected. The school administrators made what seemed like a sensible decision. On 18 March, they closed the school and sent everyone home.

It was exactly the wrong move.

Ten days later, the epidemic appeared in Nshamba village, 55 miles away. Several of the affected girls lived there. They had brought their illness home with them. But here is where the popular narrative falls apart. In Nshamba, the outbreak did not stick to teenage girls. It spread to 217 people out of a population of 10,000, including ‘young adults of both sexes and the remainder school children’.

Adult men were catching the ‘laughing disease’. How does that fit with the giggling schoolgirls story?

The school reopened on 21 May, presumably thinking the crisis had passed. Wrong again. A second wave hit immediately, affecting 57 more pupils. By the end of June, they had to close again.

The epidemic kept spreading.

On 10 June, it reached Ramashenye girls’ middle school near Bukoba. Within eight days, 48 of the school’s 154 students were affected. The connection? Rankin and Philip noted that affected girls from Kashasha lived near the Ramashenye school.

The pattern was clear. This was not spreading through the air or water. It was spreading through human contact and observation. People saw others having attacks and developed symptoms themselves. Classic mass psychogenic illness transmission.

By the time it finally burnt out in mid-1963, approximately 18 months after it began, the epidemic had forced the closure of 14 schools and affected an estimated 1,000 people. All because a school sent its students home instead of containing the outbreak.

Lost in Chaos, Not Conspiracy

While the medical side of the story is surprisingly clear, the administrative side is full of holes. There are key documents that should exist but remain missing.

The most important of these is the ‘Annual report of the Health Division 1962’ from the Tanganyikan Ministry of Health and Labour. This report would contain the definitive state-level assessment of the epidemic. But the document is not available in any publicly accessible archive.

There are also reports that the Kashasha school was sued by parents for its role in spreading the illness. The records from that lawsuit, if it happened, would be an invaluable source of evidence. Court documents would contain sworn testimony from teachers, parents, students, and officials. But these records, if they still exist, have not surfaced.

Why the gaps? Consider the events unfolding in Tanganyika at the time. The British colonial administration was packing up. The new Tanganyikan government was trying to build a civil service from scratch while simultaneously restructuring the entire political system. Government ministries were being ‘Africanised’, with European staff replaced by locals who often lacked administrative experience.

This was a jurisdictional void. The old system was leaving, the new system was not fully functional, and in between, things fell through the cracks. A mysterious illness affecting schoolchildren in a rural district? That probably ranked pretty low on the priority list of a government trying to prevent the whole country from falling apart.

There is no evidence of a deliberate cover-up. No signs that anyone tried to suppress information about the epidemic.

The gaps in the record look exactly like what you would expect from a colonial administration in retreat and a new nation struggling to find its feet. Chaos, not conspiracy.

What We’re Still Not Being Told

The evidence points to a clear conclusion.

The Tanganyika outbreak was a documented case of mass psychogenic illness, triggered by extreme psychological stress at a moment of national crisis. The diagnosis held up. So did the timeline. The way it spread matched everything we know about mass psychogenic illness.

But that diagnosis raises bigger questions that the evidence forces us to confront.

Why does the popular story directly contradict the only medical report from the scene? The myth of a joke-triggered laughter epidemic has no basis in the primary evidence. How did this fiction replace the documented reality of psychological distress?

If the on-site doctors provided a clear diagnosis in 1963, why is the event still presented as an unsolved medical mystery? The answer is not missing. It is being ignored.

What specific stressors were converging on these students in January 1962? We know about the national upheaval, the educational transformation, and the institutional pressure. But the psychological trigger was probably more specific than general anxiety about independence.

Why do most retellings incorrectly claim the epidemic only affected adolescent girls? The primary report documents the spread to adult men in Nshamba village. This detail is routinely omitted from popular accounts, making it easier to dismiss the event as teenage hysteria.

What did the local population call this illness? We have one reference to ‘Enwara Yokusheka’, which translates as ‘the illness of laughing’. But that tells us little about how the Haya people culturally understood what was happening, whether they saw it as a medical condition, a spiritual affliction, or a curse.

Was the epidemic connected to other regional events? The Tanganyika outbreak was reportedly one of three behavioural epidemics near Lake Victoria in the early 1960s, including two ‘running manias’ in Uganda in 1963. Were these related, or is the connection purely geographical and temporal?

The question the evidence cannot answer is this… how did a real psychological crisis get turned into a joke? Turning a medical crisis into an internet meme is its own kind of illness, historical amnesia about real people under real pressure.

The students at Kashasha were not laughing. They were breaking down under pressures that would challenge anyone. The fact that we have forgotten their actual experience, replacing it with a comforting fiction about contagious giggles, says more about our need for simple explanations than it does about what actually happened in those Tanganyikan classrooms.

The real epidemic may have ended in 1963. The epidemic of false narratives continues today.

Sources

Sources include: the sole contemporaneous medical report on the event, ‘An epidemic of laughing in the Bukoba district of Tanganyika’ by A.M. Rankin and P.J. Philip (Central African Journal of Medicine, 1963), which provides the foundational clinical evidence for the investigation; modern academic re-analysis of the outbreak as a ‘motor-variant’ of Mass Psychogenic Illness, particularly from researcher Christian Hempelmann; historical and political scholarship on post-independence Tanganyika, detailing the resignation of Julius Nyerere and the chaotic transformation of the colonial education and civil service systems; sociological and economic research into the Bukoba district’s colonial history and local Haya cultural dynamics; the noted absence of key official records, such as the Tanganyikan Ministry of Health’s 1962 annual report and the court records of a lawsuit reportedly filed against the Kashasha mission school; and a comparative survey of numerous secondary media accounts that document the narrative distortion of the original event over time.