What Caused the Dancing Plague of 1518?

Sometime in 1518, a farmer gathers rye from his field and leaves them in storage to dry. After a few days, the rye is collected, ground into flour, and sent off to the town baker — who uses it to make fresh-smelling, fragrant bread that everyone in town buys. 

Unbeknownst to the farmer, the baker and everyone who buys the bread, however, the rye loaves contain a deadly secret. They are contaminated with ergot, a type of mould that grows on rye… and which causes convulsions that look a lot like — well, dancing.

Was this the cause of the 1518 Dancing Plague? Some certainly think so. 

• Ergot only grows on damp rye stalks, and there was a very high possibility of stored rye being exposed to water in 1518 Strasbourg. After all, the city had just seen multiple natural disasters, including flooding. Flooded fields could have thoroughly wet the rye stalks, providing the ideal conditions for ergot to grow. 
• The bad harvests and famines that swept the city at the time probably helped, too. The combination of too little grain and too many empty stomachs meant that every stalk of rye would have been vital in feeding the people — making it entirely possible that the contaminated rye would have been eaten.
• And, of course, ergot causes hallucinations along with convulsions… which would explain the vacant, dreamlike look on some of the dancers’ faces as their bodies moved of their own accord. 

Of course, some doubt that ergot was the true reason for the plague. Experts have pointed out that the fungus restricts blood flow to the limbs, which would make it impossible for the afflicted to dance day and night as they did. Still, it remains as likely an explanation as any other. 

Sources: BBC, Camptown Media, History.com, History & Imagination 

In their attempts to find out the cause of the dance infection, the then-authorities of Strasbourg launched a full investigation. Their first stop was the house of Frau Troffea. The only person they found in the house was her very confused husband, Herr Troffea. 

After a short interview with the man, the town leaders learned some interesting information. Right before the dancing began, Herr Troffea had apparently ordered his wife to do some household chores. She had flat-out refused… and immediately began dancing out the door. 

The town leaders decided that Frau Troffea had started dancing to embarrass her husband — and that the other villagers had simply joined in to annoy their husbands. And, well, it is definitely possible. 

• Famed physician Paracelsus, who is best known today for introducing the use of chemicals and minerals into modern medicine, definitely agreed. Years after the incident took place, he visited the town and was told of the incident. His professional opinion was that Frau Troffea and the others had been acting out against their husbands, spurred on by “free and lewd thoughts”! 
• Besides, there was very little a woman could do against her husband’s wishes in 1518. Women in medieval France could not divorce their husbands, and were expected to obey their every command. It was totally possible that Frau Troffea had seized on her very public dance show as a show of defiance against her husband’s orders, and other women had done the same. 

However, the plague had affected men and children as well, not just women and wives. And if Frau Troffea and the other dancers had simply wanted to get on their husbands’ nerves, surely they would have stopped dancing before they collapsed from exhaustion! Still, we will never know for sure if their vendettas were the cause of the 1518 Dancing Plague. 

Sources: Britannica, Camptown Media, History & Imagination

Strangely enough, the Dancing Plague of 1518 is not the only odd society-wide illness in history. In 1491, a group of nuns had, in a similar way, been overcome with the urge to climb trees and meow like cats. And in what is now known as the 1962 Tanganyika Laughter Pandemic, some schoolgirls in Tanzania burst into sudden, nonstop laughter. This spread to over 1,000 people in other communities, lasted for months, and resulted in the closure of 14 schools! 

Evidently, the 1518 Dancing Plague might have been part of a bigger problem — one that experts call mass sociogenic illness (or mass psychogenic illness). Such illnesses often occur in times of stress and spread through the affected society. Ultimately, these epidemics are a kind of socially-spread mass anxiety. 

So was the 1518 Dancing Plague a mass sociogenic illness? It does make a certain sense. 

• It had been a stressful year for the people of Strasbourg. Up until that point, the people had suffered not just one but a series of famines. They had also been affected by other illnesses spreading, such as smallpox, syphilis and leprosy. Perhaps the stress of hunger and sickness tipped the people over the edge.
• Some such sociogenic illnesses take the form of a local fear. In this case, the Strasbourg people believed that those who displeased St. Vitus, who was the patron saint of epileptics and of dancers, would be cursed to dance continuously! 

It is entirely possible, therefore, that the Dancing Plague of 1518 was caused by mass anxiety. Ultimately, however, the reason for the sickness is anyone’s guess, and all we can do is speculate.

Sources: Atlas Obscura, BBC, British Psychological Society, Camptown Media, History.com, History & Imagination, National Library of Medicine