Photo of children laughing on the grass.

Mass hysteria is the phenomenon by which groups of people manifest similar or identical physical symptoms at the same time, or claim to suffer from the same thing.

Whether delusional or not, mass hysteria is a scary, though thankfully rare, thing to observe. Because witness accounts emphasize the fact that reason and common sense are the first fatality.

But in some cases not the last. As mass hysteria has been known to lead to death for some of its sufferers, as will be shown in the lines that follow.

Take a look at these 5 occurrences of mass hysteria that put another question mark on what it means to be human, rational and in control.

1. The Dancing Plague

5 occurrences of mass hysteria - The Dancing Plague of 1518

In 1518 in Strasbourg, Alsace, now part of modern day France, but then a territory of the Holy Roman Empire, a woman named Mrs. Troffea took to the streets and inexplicably started dancing. 6 days after that, others started dancing too (34 in total), until the number reached 400 a month later.

Most of them were female and some of them actually died due to exhaustion, heart attack and stroke.

Physicians called it a case of “hot blood”, but it is not known what was the actual cause.

2. Strawberries With Sugar

One of the 5 occurrences was caused by the TV soap opera Morangos Com Acucar, whose poster is pictured here.

If the influence of television on fresh malleable young minds was ever in doubt, take a look at this instance of mass hysteria which has its cause in a Portuguese soap opera called “Strawberries With Sugar” (Morangos com Açúcar).

During its popular 9 season run up until 2012, it attracted many rabid fans among teenagers who identified with the “problems” and lives of the characters presented on screen.

But they went really “rabid”, so to speak, in 2006, when 14 different schools reported a total number of 300 students claiming to have symptoms similar or identical to those that plagued the characters in an episode, namely trouble breathing, rashes, etc.

What’s really intriguing is that the show was allowed to continue after the 2006 incident up to 2012.

3. Nuns That Meow

A photo of a shocked nun.

An account attested in Justus Friedriech Hecker’s book “Epidemics of the Middle Ages” relates how a nun at a convent started meowing all of a sudden and was soon joined by the whole convent. Then, at regular intervals through the following days, all of them would meow together with eerie abandon and dedication.

The villagers living nearby finally had their fill and informed the nuns that they had obtained state permission for a company of soldiers to help them with their Cat-Nun problem. In the form of rods that the soldiers were authorized to use until the nuns ceased and desisted.

This quickly turned the nuns into good little kitties and they did indeed stop.

But who knows if the just meowed softly to each other, in the sanctuary of their convent, from then on? Or maybe they just mimed to each other a meowing cat. A difficult task, to be sure.

4. Sweet Sweet… Sewage?

One of the 5 occurrences revolves around the Mumbai sweet water craze, photographed here.

 In 2006 in Mumbai one of the most impressive cases of mass hysteria reportedly took place, in my subjective opinion.

Impressive because no matter how delusional one is, there are usually some naturally ingrained limits ingrained in each human being which generally pull on the brain’s emergency stop brake. At least in theory.

For example, we have a natural revulsion against bad smells and filth. And our whole body reacts instinctively against them, with avoidance being a priority at all costs.

Not so for many residents of Mumbai who participated in the craze surrounding filth and sewage-laden water in India. Once someone claimed that the water had turned sweet, people started confirming it is so, drinking it and storing it in plastic bottles. Ugh!

5.  Laughter Is Key

Photo of children laughing on the grass.

Yes, a sense of humor is definitely important. But for a Tanzanian village in 1962, the joke might have gone a bit too far.

Initial uncontrollable laughter in a boarding school in Tanganyika soon spread to the whole village and supposedly affected thousands of people, incapacitating some with diverse symptoms ranging from fainting, pain, trouble breathing, the onset of sudden bursts of crying amid the laughter and others.

The authorities (that weren’t affected) were baffled and didn’t know what measures to take to “cure” the population.

Still, if there’s any mass hysteria that I’d have to experience, it’d be this one. At least you get to laugh a little before the gruesome parts kick in.

Oh, and I’d love to know the boarding school joke that started it all, so I can incapacitate my friends at the next party.

While wearing noise cancelling ear-plugs myself, of course.

Image source: 1, 2, 3, 4, 5.