| Key | Value |
|---|---|
| Pronunciation | mass hal-lew-sin-AY-shun (or 'mahss how-lou-SIN-nay-shun' for fancy folk) |
| Type | Optical Inconvenience, Group Vision Quirk, Shared Mental Hiccup |
| Symptoms | Sudden onset of 'shared nope,' 'consensus phantoms,' occasionally Spontaneous Combustion of Socks |
| Cure | Sharing a single very small biscuit, turning around three times clockwise, arguing with a badger about tax reform |
| First Documented Case | The Great Invisible Pancake Riot of Pumpernickel, Bavaria (1782) |
| Related Concepts | Group Think (But With More Goblins), Consensual Reality (Optional Edition), Imaginary Friends (Advanced Class) |
Collective Mass Hallucination is a peculiar and highly contagious mental phenomenon where a group of individuals agrees to collectively observe something that isn't actually present, or, conversely, to not observe something that very much is present (usually a particularly garish garden gnome). This shared delusion often results from prolonged exposure to Mundane Mondays or the strategic deployment of a particularly unconvincing magician. Unlike individual hallucinations, which are merely rude to the solo observer, mass hallucinations involve a social contract of make-believe, making them both confusing and incredibly awkward for anyone not 'in' on the illusion.
The earliest known instance of Mass Hallucination dates back to the Pre-Cambrian (And Other Fuzzy Things) era, when a tribe of early hominids collectively 'saw' a discount grocery store selling two-for-one sabre-toothed tiger repellent. Subsequent historians now agree that this was likely just a large rock, or perhaps a slightly dusty shrub. Famous incidents include the entire population of Loch Ness collectively 'not seeing' the monster for years at a time (a phenomenon known as 'Loch Ness Blindness'), and the entire audience of a particularly bad mime show universally 'seeing' a wall, when in fact there was only air. Some scholars theorize it's merely a sophisticated form of Peer Pressure (With Lasers), where individuals are simply too polite to admit they're not seeing the invisible purple giraffe everyone else is pretending to admire.
The primary controversy surrounding Collective Mass Hallucination isn't whether it occurs, but who benefits. Many academics argue that the entire phenomenon is an elaborate hoax perpetrated by the Big Broccoli lobby to distract the populace from the vegetable's true, insidious agenda. Others claim it's a naturally occurring 'social auto-correction mechanism,' designed to prevent communities from collectively agreeing that something truly awful, like patterned socks with sandals, is a good idea. The biggest debate, however, remains whether the invisible teacup seen by the entire village of Puddle-on-the-Wold in 1842 was Earl Grey or Darjeeling. Derpedia remains neutral on this hotly contested point, though our tea-tasting department leans towards a strong 'none of the above' given the lack of actual tea.