On an otherwise unremarkable July day in early 16th century Strasbourg (now in France), a woman known as Frau Troffea ran into the street and began dancing. There was no music being played, and it wasn’t a holiday or day of celebration, yet, for reasons unknown, she felt compelled to dance. She continued her solo dance performance for almost a week, when several dozen other residents of Strasbourg joined her. Roughly a month later, there were nearly 400 people dancing in the streets of the city.
This incident became known as the Dancing Plague of 1518, and, though it sounds funny, it actually ended up claiming some lives. Several dancers died from stroke or heart attack, and a handful of others died from exhaustion. Apparently, some of the dancers did not take any breaks to eat or drink, leading to dehydration in many.
The city authorities and local physicians ended up worsening the situation at first by deciding that the dancers would only recover from their mania if they kept dancing. They hired professional dancers and musicians to help keep the seemingly crazed dancers going. They also set aside locations for them to dance. It wasn’t until September, when authorities realized their efforts at a cure were failing, that the dancers were carted away to a nearby healing shrine. Only after this did the mysterious dancing plague cease.
What’s even stranger is that this was not an isolated incident in Europe. At least ten other incidences of epidemic dancing took place in different locations in Europe, going back over a hundred years before the Strasbourg incident. The 1518 plague is the best documented, though.
Many historians have tried to discover the cause of these compulsive dancing epidemics. Ergotism has been suggested as a cause. This illness occurs when people ingest ergot, a fungus that grows on rye. It can cause delusions and strange behavior. But it also affects blood supply to the arms and legs, which would have made frenzied, long-term spells of dancing impossible.
The best explanation for the dancing plague is that this was an episode of mass hysteria. This was a stressful time for the people of Strasbourg, as famine and disease were rampant. It is possible that the extreme conditions that existed caused stress-induced psychosis. This caused the first dancer to take to the streets, and then others followed. Events snowballed, and the incident became one of mass hysteria. It also helped that the Catholic inhabitants of the city believed in the curse of St. Vitus, which was said to cause frenzied dancing.
This was the last recorded case of dancing plague in Europe. Once the severe conditions eased, it did not happen again. It has also been suggested that conversion to Protestantism and the rise of rationality helped end these plagues, since people no longer believed in things like St. Vitus’ curse. Whatever caused the end of dancing epidemics, their existence shows just how powerful psychological stress can be.