‘The Saint John’s Dancers in Molenbeeck’ (1592) by Pieter Brueghel II.

St. John’s Dance, known historically as St. Vitus Dance, was a social phenomenon involving a type of dance mania that gripped mainland Europe between the 14^th and 17^th centuries. One of the most well-known major outbreaks took place in Aachen, Germany, on the 24^th of June 1374, just several decades after the Black Death swept across Europe. During the outbreak, afflicted individuals would dance hysterically through the streets for hours, days, and apparently even months, until they collapsed due to exhaustion or died from heart attack or stroke. The number of participants at any one outbreak could reach into the thousands. In modern literature, women are often portrayed as being victims of the St. John’s Dance, although medieval accounts record that men, women and children were equally likely to be affected.

It was initially considered that the dancing mania was a curse sent by a saint, commonly thought to be St. John the Baptist or St. Vitus, hence the name of the condition. Therefore, people suffering from this condition would proceed to places dedicated to the said saint in order to pray for deliverance. The association of this phenomenon with St. Vitus can be traced to an incident that happened in Germany in 1278. During that year, a group of 200 people were dancing so vigorously on a bridge over the Maas River that the bridge collapsed, killing many of the dancers. Those who survived were taken to a nearby chapel dedicated to St. Vitus, and many of them were reported to have been restored to full health.

Interestingly, these were not isolated events, but occurred numerous times throughout Medieval Europe. Outbreaks occurred in Italy, Luxembourg, France, Germany, Holland, and Switzerland over the following three centuries.

An engraving of participants in a dancing mania. Photo source: Wikipedia.

Several hypotheses have been put forward to explain this phenomenon. For instance, ergot poisoning has been blamed by some for the hallucinations and convulsions that accompanied the St. John’s Dance. This form of poisoning coincided with floods and wet growing seasons, as the damp condition was suitable for the growth of the fungus claviceps purpura, which contains toxic and psychoactive chemicals, including lysergic acid and ergotamine (used in modern times as a precursor in the synthesis of LSD). This fungus is usually found on cultivated grain such as rye, and may induce certain symptoms of the St. John’s Dance including nervous spasms, psychotic delusions, and convulsions. Nevertheless, it has been argued that the outbreaks usually do not happen during the floods or wet seasons. Furthermore, not all the symptoms of the St. John’s Dance can be attributed to ergot poisoning.

Another explanation for the St. John’s Dance is that those participating in it were followers of deviant religious sects. As these people made pilgrimages throughout Europe during the years following the Black Death in order to gain divine favour, they grew in numbers. As they were involved in prolonged dancing, fasting, and emotional worship, such symptoms as hallucinating, fainting, and trembling uncontrollably would have been common.

Although it is highly plausible that some of the participants of the St. John’s Dance were genuinely affected by mental illnesses, it has been argued that the majority of those engaged in the dance did not actually suffered from any of the symptoms. Instead of looking at the St. John’s Dance as a form of mental disorder, it may be considered as a social phenomenon, sometimes referred to as ‘mass psychogenic illness’. This involves the occurrence of similar physical symptoms, with no known cause, which affect a large group of people as a form of social influence. Perhaps it may be suggested that some of those engaged in the St. John’s Dance did so out of fear, while others danced in order to fit in with the crowd.

While this form of mass hysteria may seem to belong to the history books, it is in fact just as common in modern times.  The Tanganyika laughter epidemic of 1962, for example, was an outbreak of mass hysteria in Tanzania in which uncontrollable laughter, accompanied by fainting, respiratory problems, and crying, spread from a group of school girls, to the entire school, neighbouring schools, and entire villages. Thousands of people were affected to some degree. The phenomenon was not completely eradicated for some eighteen months!

Such occurrences of mass hysteria have continued to confound the medical community and while it is easy to laugh off as ridiculous and bizarre behaviour, research has shown that there are a number of complex factors that can contribute to the formation and spread of collective hysteria, including rumours, extraordinary anxiety or excitement, cultural beliefs, social and political context, reinforcing actions by authority figures, and stress.  Cases of mass hysteria have been reported all over the world for centuries and provide a fascinating insight into the complex nature of human psychology!