Case file · High strangeness
The dancing mania of 1374
In summer 1374, crowds began dancing uncontrollably in Aachen; the mania spread along the Rhine to Cologne, Metz and the Low Countries.
1374 CE · 50.77, 6.08 · status: unexplained
The account
Dancers screamed, saw visions and collapsed; priests treated them as possessed.
The sceptical view
Explanations include mass psychogenic illness after floods and plague; ergot poisoning is unlikely.
The researched reading
A real epidemic of compulsive dancing among stressed, devout populations. Mass psychogenic illness shaped by belief explains it far better than poison or the supernatural.
| Explanation | Weight | Why |
|---|---|---|
| Perception, memory or mind | 40% | Historian John Waller argues the outbreaks fit mass psychogenic illness among people in distress, after floods, famine and plague, who believed in dancing curses tied to saints. Trance and contagion spread the behaviour along trade routes. |
| A cultural story | 20% | Belief in St John’s and St Vitus’s dance, possession and pilgrimage gave the episodes their shape. Chroniclers also wrote moralised accounts. |
| Undetermined | 20% | The share a generic explanation had beyond what has been shown for this case: it fits many cases like this one, but has not been demonstrated for this one. |
| A known natural phenomenon | 8% | Disease, such as encephalitis or neurological conditions, may explain some individuals but not the coordinated spread. |
| Something in the surroundings | 5% | Ergot poisoning from mouldy rye causes convulsions and hallucinations. However, it rarely produces sustained coordinated dancing and does not fit the spread across regions. |
| A hoax or fabrication | 4% | Some participants may have been beggars or opportunists, as some chroniclers alleged. |
| Genuinely anomalous | 3% | Well explained by known social and psychological mechanisms. |
Official position: Clergy treated the dancers as possessed; modern historians favour mass psychogenic illness.
Connections in the atlas
- The dancing plague of Strasbourg
- St Vitus sends the dancing curse