10 Strangest Mass Hysterias

During the Middle Ages, many nuns were forced into convents by their parents and often stressed by a lifestyle not of their own choosing — one that demanded celibacy, poverty and hard manual labor. Two especially bizarre cases of mass hysteria involved meowing and biting nuns.

In the first case, a nun in a large French convent began meowing one day. Soon others joined in, and eventually every nun in the convent was meowing. The noise became structured; all of the nuns would meow together for several hours at the same time every day. The neighbors could hear the collective caterwauling and were understandably annoyed. Eventually the nuns quieted down after being threatened with a beating by soldiers.

Next door in Germany, in the 15th century, a nun began biting the other sisters in her convent. It wasn't too long before all of the nuns were biting one another. Word spread about the biting nuns, presumed to have caught some type of nefarious infection, and soon the "infection" spread to convents throughout a large portion of Germany, mostly in Saxony and Brandenburg. But it didn't stop there; convents in Holland and even Rome were also affected [source: Bartholomew and Goode]. The nuns eventually stopped biting because of exhaustion [source: Wundt].

Despite the July heat in 1518, Frau Troffea began silently dancing in the streets of Strasbourg, France. She'd kept up her bizarre dance marathon for nearly a week when suddenly other citizens began joining her. Soon the streets were filled with three dozen dancers. By August, an astounding 400 were shimmying and shaking nonstop all over the city.

Stunned and puzzled, doctors nevertheless proclaimed this affliction was caused by fever and recommended the dancers keep at it until their fevers were gone. The city tried to help, constructing a dance stage and bringing in a band and professional dancers, presumably to entertain the victims during their uncontrollable gyrations.

But people began collapsing from exhaustion and the heat. Some even died. The hysteria, which is well-documented in historical records, didn't end until the dancers were finally removed from the streets (they were taken to a shrine to pray for absolution).

What brought on the dancing plague? Possibly stress. Disease and famine were sweeping through Strasbourg at the time. Many people were reduced to begging. It was also a superstitious period; one common belief among Catholics was that St. Vitus could curse you with a dancing plague [sources: Andrews, Wallis].

It all began when young Betty Parris and Abigail Williams began screaming uncontrollably and flailing about. A doctor declared the two residents of Massachusetts' rural Salem Village bewitched. Soon several other young girls came down with similar symptoms, putting the blame on three villagers, all women, as the ones who had bewitched them.

The women were brought to trial. Two denied the accusations, but one — a Caribbean slave named Tituba — confessed to bewitching the girls and offered to name other witches, likely a ploy to save herself from execution (it worked) [sources: History, University of Virginia].

As more people were swept up in the accusations, some confessed and pointed the finger at even more people. Hysteria flooded the village and spilled over into the rest of Massachusetts. Five months after Parris and Williams first suffered fits, the courts were clogged with witchcraft cases.

The mayhem finally died down about a year later, after several respected citizens began pushing for solid evidence to be presented in the witchcraft trials, as opposed to relying on dreams and visions. By the time the trials were stopped, 19 people had been hanged, seven died in jail awaiting execution and one man had been pressed to death by stones. In all, 200 people were accused of practicing witchcraft [sources: History, Blumberg]

Kissing bugs, a subfamily of assassin bugs, feed on the blood of mammals, including humans. Often entering homes and outhouses, they like to bite the thinner skin of a victim's face or lips, which make for an easier snack. When kissing bugs bite, they can be quite painful, and some carry disease [source: University of Wisconsin-Milwaukee].

In 1899, a kissing bug epidemic exploded in the northeastern U.S. More than 60 newspaper articles from around the nation breathlessly reported accounts of people waking up with swollen eyelids and lips. Although swelling subsided usually in two or three days, the papers noted a few cases of death from these bugs. Residents of cities from Boston to Atlanta became terrified of all flying insects and began sending bug specimens to entomologists, asking whether their specimen was a deadly kissing bug [Garcia et al.].

When entomologists examined these bugs, they found a variety of insects, ranging from houseflies to beetles to bees. Leland Howard, entomology chief for the U.S. Department of Agriculture, referred to this scare as a "newspaper epidemic, for every insect bite where the biter was not at once recognized was attributed to the popular and somewhat mysterious creature" [source: Bartholomew and Evans].The panic apparently subsided when newspapers stopped covering it.

For nearly two weeks in November 1938, residents living in Halifax, England, were terrorized by a man racing around in the dark, slashing women with a knife or razor. The panic began Nov. 16, when two women arrived at a local police station, both with head wounds that appeared to be caused by some kind of blade. They'd been attacked by a man, they told police. Five days later, a third woman ran to the police with a deep razor-like cut in her wrist. In both cases, no evidence was found at the crime scenes. Police were stumped, and citizens became concerned [source: Glover].

Over the next week, more people were mysteriously attacked, all suffering some type of cut. By now the public was referring to the attacker as the "Halifax Slasher," and police said there could be up to three different men attacking victims. Businesses shuttered their windows. Vigilante groups formed, sometimes attacking men who appeared suspicious or out of place. Law enforcement officials put in a call to Scotland Yard for help, and two detectives arrived Nov. 29 [source: Gerber].

As the investigators began questioning the victims, their stories collapsed. Suddenly, everyone began confessing that they had actually cut or injured themselves. One woman said she fought with her boyfriend and, upset, sliced her arm because she had heard about the Halifax Slasher. After nine of the 12 victims confessed to self-harm, police closed the investigation. The nine were all criminally charged, with four going to jail [source: Gerber].

At a small girls' boarding school in Tanganyika (now Tanzania), three students started to giggle. Starting and stopping abruptly, their fits would last anywhere from a minute or two to several hours. This "laughter" proved contagious — soon other girls were doing the same thing. No one could concentrate on their schoolwork, and restraining the laughing students proved ineffective. Six weeks later, more than half of the school's middle and high schoolers had caught the laughing bug.

School officials shut the place down. But when they reopened it two months later, the laughing plague immediately restarted and the school was once again shuttered. The laughing epidemic spread to other schools and lasted somewhere between six and 18 months [sources: McGraw and Warner, Sebastian].

So what caused this? "The bad news is, it had nothing to do with humor. There was no merriment. Laughter was one of many symptoms," said linguist Christian F. Hempelmann, who researched the incident. He noted that the students also had fits of pain, fainting, crying and rashes.

He blamed excessive stress for the uncontrollable giggles. The boarding school where the laughter began was a very strict one. Plus the country had just gained its independence, and people were anxious about the future. With all of the terrorism in the world today, experts say another laughing epidemic wouldn't be surprising [sources: McGraw and Warner, Sebastian].

It all began when a mother (who was mentally unstable) accused Ray Buckey, a worker the McMartin Preschool near Los Angeles, of raping her child. Although police were initially skeptical, in an abundance of caution they sent letters home to the parents of other children at the day care center asking them to question their children about acts like sodomy and oral sex. As parents talked to their kids and to each other, more accusations followed. Buckey, his mother, Peggy McMartin (who owned the school), and other teachers were eventually charged with 208 counts of child molestation [sources: Wasserman, Haberman].

As time went on, and social workers were brought in to "get more information" out of the young children, the accusations got wilder. In addition to being raped and sodomized, the children said they'd participated in Satanic rituals, been forced to drink blood and had witnessed a baby being sacrificed in a church. The ensuing trial lasted several years, but none of the defendants was found guilty of anything.

During the years the McMartin trial was going on, and even after, similar allegations were leveled against day care centers and their employees in 46 states. At the Little Rascals Day Care Center in North Carolina, for instance, defendants were accused of sexual abuse as well as a host of other actions involving spaceships, hot air balloons and pirate ships. Many people were found guilty, only to be released later when their convictions were overturned [sources: Wasserman, Haberman, Little Rascals Day Care Case].

No one knows for sure how things got so out of hand. Richard Beck, author of the book "We Believe the Children," says during that era many adults were worried about crime and the decline of respect for traditional authority. Add to that the media coverage that reported everything at face value — and the leading questions social workers asked the children at the day care centers — and you've got a full-fledged panic [source: Casey].

In the spring of 1983, nearly 1,000 young Arabs in the West Bank suddenly became ill with a mysterious ailment characterized by symptoms like headache, dizziness, blurred vision, abdominal pain, weakness and fainting. Seventy percent of the patients were schoolgirls 12 to 17 years old [source: Centers for Disease Control and Prevention].

When some of the early victims said they smelled a strange odor reminiscent of rotten eggs in their classroom before falling ill, Palestinian leaders accused the Israelis of using chemical warfare to drive away the Arabs; some even claimed it was to sterilize Arab females. Israeli officials, in turn, said Palestinians were using chemicals on their own people to stir up trouble [sources: Shipler].

After schools closed in the West Bank, no additional illnesses occurred. And no trace of chemical residue was found in any of the buildings. Health authorities determined that the initial group to fall ill may have been affected by the smell of low levels of hydrogen sulfide gas escaping from a latrine. But the bulk of the sufferers became ill because of psychological factors, namely stress and anxiety, which were likely caused or heightened by news reports suggesting a toxic gas was the culprit.

In May 2006, more than 300 Portuguese schoolkids began complaining they were sick. Many were having problems breathing. Some were dizzy. Others developed rashes. The kids were scattered at 14 different schools around the country, and some of the schools were forced to close [source: China Daily]. Was it possible a deadly virus had descended upon the country?

Here's the intriguing part: These issues developed just a few days after a popular teen soap opera "Morangos com Açúcar" ("Strawberries with Sugar") aired an episode about a mysterious, life-threatening virus. The show centers on the lives of Portuguese kids, and in the episode, the virus was striking children at a school.

After much study, medical officials decided the TV program was part of the problem. Some kids who had allergies or rashes became fearful their ailments were actually serious health problems after viewing the show. Other kids developed the "illness" because they were stressed about the upcoming end-of-year exams. And some merely suffered from collective delusion. How could experts be so sure? "I know of no disease which is so selective that it only attacks schoolchildren," Dr. Mario Almeida told local daily Correio de Manha.

Experts blamed a whole raft of things for the illness that struck several students and one teacher at Virginia's William Byrd High School: Carbon dioxide from the photography classroom. Lead paint. Drugs. Chronic Fatigue Syndrome. Even swamp gas and raging hormones.

In September 2007, a student at the high school fell ill with tremors, twitching, dizziness and headaches. Soon nearly a dozen people were afflicted, causing alarm in the school and community. School officials were urged to close the institution; at one point about 300 of the school's 1,200 students were staying home.

Virginia's Department of Health swept in, performing innumerable tests to see whether there was an environmental issue causing the symptoms. But after weeks of study, all results were negative. The conclusion: a sociogenic problem (i.e., one produced by societal issues). In other words, mass hysteria. The reason for the hysteria was presumed to be stress. However, the school superintendent was uncertain, saying these students were no more stressed than any others [source: Jeffries].