When Minds Unite: 50 Cases of Mass Hysteria That Defy Explanation

Reports of a mysterious attacker with a razor blade gripped the English town of Halifax in November 1938, resulting in 12 random victims. Vigilante groups formed, but it turned out the "Halifax Slasher" was a hoax-all the victims had made up the attacks, some even slashing themselves. Four individuals faced prison time for their false reports, ironically creating real criminals in the process.

During the Vietnam War, the Hmong people, who had fought alongside the French and later the CIA, faced dire conditions when the U.S. withdrew. Mysterious yellow rain in Southeast Asia was initially thought to be a Soviet chemical weapon, causing panic. However, Harvard biologist Matt Meselson discovered it was non-toxic bee feces, challenging the initial narrative. Persecution and wartime hardships made the Hmong hesitant to accept this explanation, highlighting the complex repercussions of conflict on communities.

The Hammersmith Ghost hysteria unfolded in 1803 when reports of ghost sightings in west London fueled fear and panic. People believed the spirit to be that of a recent suicide victim buried in Hammersmith, describing it as a tall figure in white with additional details such as horns and glass eyes. The mass hysteria led to tragic consequences, with an innocent man, Thomas Millwood, mistakenly shot and killed by a fearful resident, Francis Smith, who thought he was encountering the ghost.

The Irish Fright occurred in December 1688, during the Glorious Revolution in England. Rumors spread that Irish soldiers, part of the Jacobite Irish Army supporting King James II, were planning to massacre and pillage in retaliation for James's overthrow. The false reports triggered panic, leading to mass mobilization for defense. The panic spread rapidly across England, reaching at least nineteen counties, with towns mobilizing militias and arming against the supposed Irish threat. The Fright subsided within days, and while its instigators remain unclear, it reflected the febrile political climate after James II's flight and anti-Catholic sentiments.

On July 13, 1986, during a marching band competition at England's Hollinwell Showground in the town of Kirkby-in-Ashfield, nearly 300 students fell silent and collapsed, experiencing shared symptoms like burning eyes, nausea, headaches, and stomach cramps. The mysterious event, known as "All Fall Down," hospitalized 259 individuals. Despite decades of speculation, ranging from mass hysteria to the potential impact of a pesticide sprayed on the field, no conclusive explanation has confirmed the cause.

The ghost rockets reported over Scandinavia in 1946, mainly in Sweden, were concluded by German, British, and Scandinavian intelligence officials to be a case of mass hysteria. Investigations logged approximately 2,000 sightings of rocket- or missile-shaped unidentified flying objects between May and December 1946, attributing many sightings to meteors. Despite some suspicions of Soviet involvement, the phenomenon spread to other countries, prompting a search for extraterrestrial origins, particularly in Greece, where physicist Paul Santorini led an investigation before it was abruptly stopped.

Civilian pilot Kenneth Arnold's report of disc-shaped objects on June 24 sparked the 1947 flying disc craze in the United States, which quickly spread, with at least 800 "copycat" reports in subsequent weeks, peaking on July 7 and largely subsiding by July 10. Mainstream sources attributed the reports to novel technology, mistaken identifications, or mass hysteria, while fringe theories speculated on extraterrestrial origins or apocalyptic significance. Scholars regard the 1947 craze as the "birth of a modern myth" and analyze it within folklore and religious studies frameworks.

In October 2011, a mysterious outbreak of violent twitching and jerking affected initially two and later 20 people, mostly teenage girls, at Le Roy Junior/Senior High School near Buffalo, New York. Concerns arose about water supply and contamination, but environmentalists found no evidence. Dr. Laszlo Mechtler attributed the symptoms to mass hysteria, which social and mainstream media attention exacerbated, and noted that many affected individuals returned to normal by the end of the school term.

In 2016, Havana syndrome, a cluster of symptoms experienced mostly by U.S. government officials and military personnel abroad, was first reported in Havana, Cuba, and later in various locations globally. At first, the attacks were blamed on unknown foreign agents using unknown weapons. However, investigations and reviews, including one by seven U.S. intelligence agencies in March 2023, consistently pointed away from the involvement of U.S. enemies, calling it "very unlikely" that foreigners were involved. Despite this conclusion, Pentagon-funded experiments attempting to recreate Havana syndrome in animals through extended RF wave exposure continued.

Emirates Flight 203, carrying 521 passengers from Dubai to New York in September 2018, experienced a mass hysteria incident when approximately 100 passengers reported symptoms like coughing and fever. Health authorities quarantined the plane at John F. Kennedy International Airport and evaluated passengers, sending 11 to the hospital. However, the belief that others were also sick spread, contributing to the incident labeled the "flight from hell," despite only a few passengers having common colds or the flu.