Authorities prescribed "more dancing" to cure the tormented movers but, by summer's end, dozens in the Alsatian city had died of heart attacks, strokes and sheer exhaustion due to nonstop dancing. For centuries this bizarre event, known variously as the dancing plague or epidemic of 1518, has stumped scientists attempting to find a cause for the mindless, intense and ultimately deadly dance. Historian John Waller, author of the forthcoming book, "A Time to Dance, A Time to Die: The Extraordinary Story of the Dancing Plague of 1518," studied the illness at length and has solved the mystery. "That the event took place is undisputed," said Waller, a Michigan State University professor who has also authored a paper on the topic, which has been accepted for publication in the journal Endeavour. Waller explained that historical records documenting the dancing deaths, such as physician notes, cathedral sermons, local and regional chronicles, and even notes issued by the Strasbourg city council during the height of the boogying rage, all "are unambiguous on the fact that (victims) danced." "These people were not just trembling, shaking or convulsing; although they were entranced, their arms and legs were moving as if they were purposefully dancing," he said. Possible Causes Eugene Backman, author of the 1952 book "Religious Dances in the Christian Church and in Popular Medicine," sought a biological or chemical origin for the dancing mania. Backman and other experts at the time believed the most likely explanation was ergot, a mold that grows on the stalks of damp rye. When consumed unknowingly in bread, the mold can trigger violent convulsion and delusions but not, Waller says, "coordinated movements that last for days." While at Australia's James Cook University, sociologist Robert Bartholomew proposed a theory that the dancers were performing an ecstatic ritual of a heretical sect, but Waller counters, "there is no evidence that the dancers wanted to dance." "On the contrary," he added, "they expressed fear and desperation," according to the written accounts. Unusual Events Preceded the Epidemic A series of famines, resulting from bitter cold winters, scorching summers, sudden crop frosts and terrifying hailstorms, preceded the maniacal dancing, Waller said. Waves of deaths followed from malnutrition. People who survived were often forced to slaughter all of their farm animals, secure loans and finally, take to the streets begging. Smallpox, syphilis, leprosy and even a new disease known as "the English sweat" swept through the area. "Anxiety and false fears gripped the region," Waller said. One of these fears, originating from a Christian church legend, was that if anyone provoked the wrath of Saint Vitus, a Sicilian martyred in 303 A.D., he would send down plagues of compulsive dancing. Waller therefore believes a phenomenon known as "mass psychogenic illness," a form of mass hysteria usually preceded by intolerable levels of psychological distress, caused the dancing epidemic. Mass Hysteria Ivan Crozier, a lecturer in the Science Studies Unit at the University of Edinburgh, told Discovery News that he "agrees completely" with Waller's conclusion. "His cultural explanation, combined with a contextualized view of the conditions in which people lived at the time on the Rhine and Mosel, is very convincing and is superior to the arguments about ergot, which is a compound like LSD," Crozier said. "Ergot gave people visions, not energy to dance," he added. Crozier is a world authority on yet another mass hysteria epidemic: koro. Since at least 300 B.C., plagues of koro -- an irrational male fear that one's genitals have been stolen or are fatally shrinking into the body -- have swept through various parts of the world, particularly throughout Africa and Asia. Most recently, a 1967 outbreak, documented in the Singapore Medical Journal, caused over 1,000 men to use pegs and clamps in hopes of protecting themselves from the gripping fear. "In both cases we see cultural issues impacting on collective behavior," Crozier said, explaining that preexisting superstitions, fears and beliefs surrounding both koro and the dancing epidemic led to group beliefs turning into "collective action." Waller explained that victims often go into an involuntary trance state, fueled by psychological stress and the expectation of succumbing to an altered state. "Thus, in groups subject to severe social and economic hardship, trance can be highly contagious," he said. More Deadly Dancing, And Laughing At least seven other outbreaks of the dancing epidemic occurred in medieval Europe, mostly in the areas surrounding Strasbourg. In more recent history, a major outbreak occurred in Madagascar in the 1840's, according to medical reports that described "people dancing wildly, in a state of trance, convinced that they were possessed by spirits." Perhaps the most unusual documented case of mass psychogenic illness was the Tanganyika Laughter Epidemic of 1962. A paper published the following year in the Central African Journal of Medicine described what happened. Triggered by a joke among students at a Tanzania boarding school, young girls began to laugh uncontrollably. At first there were spurts of laughter, which extended to hours and then days. The victims, virtually all female, suffered pain, fainting, respiratory problems, rashes and crying attacks, all related to the hysterical laughter. Proving the old adage that laughter can be contagious, the epidemic spread to the parents of the students as well as to other schools and surrounding villages. Eighteen months passed before the laughter epidemic ended. Curing the Mind According to medical epidemiologist Timothy Jones, an assistant clinical professor of preventative medicine at the Vanderbilt University School of Medicine, who also reported an incident of hysteria in Belgium following soft-drink consumption, "Outbreaks of psychogenic illness are likely to be more common than is currently appreciated, and many go unrecognized." Jones recommends that physicians treating such problems "attempt to separate persons with illness associated with the outbreak," conduct tests to rule out other causes, monitor and provide oxygen for hyperventilation, attempt to minimize the individual's anxiety, notify public health authorities and seek to assure patients that, while their symptoms "are real…rumors and reports of suspected causes are not equivalent to confirmed results." Aside from their medical interest, Waller believes such epidemics, particularly those from past centuries, are "of immense historical value." He said the dancing plague "tells us much about the extraordinary supernaturalism of late medieval people, but it also reveals the extremes to which fear and irrationality can lead us." He added, "Few events in my view so clearly show the extraordinary potentials of the human mind."
Submitted for consideration: Dancing as a subconscious or superstitious or symbolic expression of territoriality.