A device or effect that makes people less intelligent. (Usually temporarily.)

Generally played for comedy, with the afflicted people talking in [[SimpletonVoice exaggerated "stupid" dialect]] and making decisions that are a TakeThat against whatever the writers oppose. In almost all cases, the effect hits both "book smarts" and "common sense", even though they're different kinds of intelligence. For extra fun, one character will be functionally immune to the effect due to already being stupid.

Can be used to justify the IdiotBall, as opposed to PlotInducedStupidity, which does not bother with an explanation.

When someone's using this as a weapon, it's a type of StupidityInducingAttack.

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!!Examples:

[[foldercontrol]]

[[folder:Comic Books]]
* The ''ComicBook/JudgeDredd'' comic had an experimental weapon named "the Stupid Gun." It fell into the wrong hands--HilarityEnsues.
* In ''SuperMarioBros'' #5 (from ValiantComics), King Koopa's (full name "Bowser Koopa") science team comes up with "the Stoopid Bomb." The King of the Mushroom Kingdom, being an idiot, is unaffected, but everyone else becomes foolish, including King Koopa's own troops, as the bombs are on a hair trigger and keep getting dropped. There are also antidote Smart Bombs, but they are all used on one Shyguy, who becomes a genius and temporarily wrests control from Koopa. Too bad he's now the OnlySaneMan.
* The end of the PresidentEvil arc in the {{DCU}} explained ComicBook/LexLuthor's blaming {{Superman}} for a kryptonite meteor heading for Earth, putting on PoweredArmor, and ranting madly on national TV, by him having injected himself with a mind-altering mixture of Bane's Venom formula and liquid kryptonite. Why he decided he needed some pretty low level SuperStrength despite being the President of the United States is definitely PlotInducedStupidity though. Damn you Loeb.
** Drinking green, radiated rocks from outer space in liquid form is even worse. And don't forget this IS the guy who had cancer because he wore a Kryptonite ring all the time.
** Geoff Johns [[InfiniteCrisis later]] threw in a revelation that Lex's recent bouts of stupidity were caused by the presence of his AlternateUniverse 'counterpart', Alex Luthor Jr. Somehow. [[VoodooShark Even though he is actually]] ''[[VoodooShark the son]]'' [[VoodooShark of his universe's Lex.]]
** The above gets some possibly unintentional FridgeBrilliance from the fact that ''before'' Luthor's total breakdown, in ''Adventures of Superman'' #600, he had a brief period of amnesia during which he became a radical anti-corporate villain, in essence the opposite of regular-Luthor. During this story he called himself ... Alex.
* In the utterly depressing [[AlternateUniverse alternate]] MarvelUniverse that serves as the setting for ''Mutant X'', there is a DumbMuscle character called The Brute. He used to be brilliant scientist Hank [=McCoy=] before his notorious ProfessorGuineaPig tendencies took a tragic turn, leaving him too stupid to figure out how to reverse what he'd done to himself.
* Maul of the comic book ''WildCATS'' has size-changing powers that makes his intelligence inversely proportional. Not only does growing make him dumber, he later discovers he can shrink to get smarter, although this proves exhausting.
[[/folder]]

[[folder:Literature]]
* There was at least one AirportFantasy-style disaster novel which had this effect as the result of a communicable disease. Toward the end, a newscaster (who is having trouble reading the [=TelePrompTer=]) notes that sales of all literature except pornography have fallen drastically. The heroes finally found a cure, but were uncertain if anyone would want it anymore.
** This sounds like ''IQ 83'' by [[http://en.wikipedia.org/wiki/Arthur_Herzog Arthur Herzog]].
* "Bimbo Rays" are popular in certain kinds of fetish fiction.
** You heard this right. It's often combined with ProfessorGuineaPig and GenderBender in most circles.
* "AUM" in the ''Literature/{{Illuminatus}}'' trilogy is a hallucinogenic drug cocktail that renders users highly creative and supremely gullible at once. When one character tests it by spiking the punch at a meeting of a FictionalCounterpart to the Knights of Columbus, the group ends up renouncing Christ and adopting geocentrism.
** Unlike most examples, this stuff tends to make people ''more'' intelligent, not less. Initially they believe almost everything that follows some kind of logic, but since it stimulates inquisitivness and curiosity, it tends to produce more knowledgeable and open-minded people, on average. It's implied that sometimes the opposite can happen as well, but those examples are never seen in the book.
* In the short, short story ''I Wish I May, I Wish I Might'' by Bill Pronzini, a retarded boy finds a genie in a bottle which offers to grant him three wishes. One of them? "I'm going to wish for all the little boys and girls in the world to be just like me so I'll never-ever be without somebody to play with."
* An example where the change is permanent, the Creator/StephenKing short story ''[[Literature/NightmaresAndDreamScapes The End of the Whole Mess]]'', was about some Phlebotinum applied to the world's water supply in order to make everyone less aggressive. It worked, but it caused the end of the world anyway, because a side-effect was rapid onset dementia/Alzheimer's.
* The novel ''BimbosOfTheDeathSun'' is centered around the author of a [[ShowWithinAShow novel within a novel]] with the same name, whose basic premise involves solar radiation messing up computers; as a side effect, it also make women world-wide lose intelligence. Despite what it sounds like, he wasn't doing it to [[AuthorTract make any kind of social point or be chauvinistic]] -- the idea was simply based off of the fact that some diseases are linked to sex.
* In Robert Forward's ''Rocheworld,'' the ship's crew are given a drug ([=NoDie=]) that greatly extends their lifespans at the expense of making them stupid. The ship's AI stops administering the drug when they get to their destination, and their intelligence comes back.
[[/folder]]

[[folder:Live Action TV]]
* The ''Series/BuffyTheVampireSlayer'' episode "Beer Bad." Buffy drinks cursed beer which turns her into a cavewoman. (Although she still looks the same, the guys who drink the beer literally look like cavemen. Granted, Xander expressly cut her off before the rest) Ends with a SpoofAesop:
--> '''Xander:''' And was there a lesson in all this? huh? What did we learn about beer?
--> '''Cave Buffy:''' Foamy.
-->'''Xander:''' Good, just as long as that's clear.
** Of course, the beer itself wasn't a good idea for someone who can literally punch through car doors.
-->'''Giles''': I can't believe you served Buffy that beer.
-->'''Xander''': I didn't know it was evil.
-->'''Giles''': You knew it was beer!
** Another ''Buffy'' episode had Ethan Rayne selling chocolate that made people act like particularly irresponsible teenagers. This is notable because "book smarts" weren't affected so much as common sense was. Buffy wound up having to be the responsible, mature one.
** It seemed to depend on what sort of person the reverted individual was as a teen. The principal was, and became again, a dweeb and mindless hanger-on to whoever seemed coolest (in this case, Buffy.) Giles was, and became again, a danger to everyone around him.
* In the ''{{Series/Eureka}}'' episode "E=MC...?", eating cloned chicken meat causes most of the town to lose their knowledge, common sense, attention span, emotional maturity, etc.
* ''Series/MontyPythonsFlyingCircus'' - In the "Gumby Surgery" sketch, the head surgeon (Graham Chapman) is perfectly intelligent and lucid while asking the nurse for glasses, mustache, and handkerchief. As soon as the latter is put on, he turns into the usual Gumby idiot/madman: "I'm going to operate!"
[[/folder]]

[[folder:Newspaper Comics]]
* In ''ComicStrip/TomTheDancingBug'', [[http://www.gocomics.com/tomthedancingbug/2013/06/13 "Flowers for Trinitron"]] uses this trope to create FlowersForAlgernonSyndrome. A television causes stupidity. A man is watching ''Series/NYPDBlue'' when the cable goes out. The man, cut from TV, becomes gradually smarter over the next six days. He reads ''Literature/EastOfEden'', volunteers at a homeless shelter, and shifts his handwriting from print to cursive. He is about to destroy his TV, when the cable comes back and ''Series/WheelOfFortune'' comes on. The man soon reverts to stupidity.
* ComicStrip/CalvinAndHobbes:
--> '''Calvin:''' [[http://www.gocomics.com/calvinandhobbes/1991/03/15 I have in my hand an invisible cretinizer! One shot renders the victim a babbling simp, a dolt, an utter moron!]]\\
'''Ronald:''' OH SURE, CALVIN! GIVE US A BREAK!\\
'''Calvin:''' As Ronald proves, it's quite effective even at long range.
[[/folder]]

[[folder:Tabletop Games]]

* In the ''TabletopGame/DungeonsAndDragons'' campaign setting ''TabletopGame/{{Ravenloft}}'', the mysterious [[PowersThatBe Dark Powers]] that control the [[PocketDimension Demiplane of Dread]] maintain this as a general effect on the inhabitants so that they do not question the bizarre nature of the world they live in or the way its individual domains cross different TechnologyLevels and genres. For example, the inhabitants of the domain of Lamordia (based on Franchise/{{Frankenstein}}), are not great believers in magic despite the neighboring domain of Darkon being a StandardFantasySetting.

[[/folder]]

[[folder:Toys]]
* One of the Vahki models in ''{{Bionicle}}'' had the ability to temporarily overwrite a Matoran's conciousness and turn them into a mindless "shambler" incapable of rational thought.
** It also occured to Vezok when he got a LiteralSplitPersonality - the original Vezok lost a few IQ points because the part split off got his ability to think tactically.
[[/folder]]

[[folder:Video Games]]
* In the game ''VideoGame/{{Psychonauts}}'' using super-powerful sneezing powder to make people ''literally sneeze their brains out'' results in the person turning into a listless zombie obsessed with television (and hacky-sack, for some reason).
** The trope is also inverted in the case of Ford Cruller, who (due to a crippling psychic battle) is schizophrenic and amnesic when he's ''not'' near the [[GreenRocks Psitanium]] deposit.
* The plot of the point-and-click adventure game ''ZakMcKrackenAndTheAlienMindbenders'' revolves around aliens who took over the phone company and are sending out a signal that makes people stupid.
* In ''SoulNomadAndTheWorldEaters'', [[spoiler:Danette appears to be TheDitz for much of the game, but it turns out that the block on her memories is to blame. When it's finally removed, she's only a little bit ditzy.]]
[[/folder]]

[[folder:Webcomics]]
* In the first Djinn arc of ''TheWotch'', a wish turns all girls ''except'' blondes into stupid bimbos.
[[/folder]]

[[folder:Western Animation]]
* In ''WesternAnimation/{{Futurama}}'', Fry is the only one immune to the giant brains' stupefying effect due to his...unique...brain structure, which is normally a handicap.
** I already did!
*** No I'm... doesn't.
* In an episode of ''WesternAnimation/ChalkZone'', Craniac 3 tries to get Rudy with a smart bomb. It is sentient, though, and does not want to blow itself up. He instead opts for the Dumb Dart, which lowers intelligence.
* An episode of ''WesternAnimation/KimPossible'' had Dr. Drakken using "silly hats" to reduce the world's leading scientists to blithering idiots.
* In one episode of ''WesternAnimation/AdventuresOfSonicTheHedgehog,'' Dr. Robotnik accidentally takes a stupid pill instead of a smart pill. In another episode he invents a ray that does this.
* In an early episode of ''WesternAnimation/TheAdventuresOfJimmyNeutronBoyGenius'' Jimmy builds a "brain drain" helmet to lower his intelligence to normal levels. Unfortunately, the helmet works a little too well and he becomes a blithering idiot.
* ''WesternAnimation/SpongeBobSquarePants'': "You won't get away Man-Ray; not while we have the Orb of Confusion!" Which, by the way, causes a wave of confusion that ''starts'' with the person who turned it on, making it a very ''literal'' IdiotBall.
* An episode of ''WesternAnimation/RockyAndBullwinkle'' featured "goof gas". Bullwinkle was too stupid to be affected by it. Boris remarked something like, "Goof gas affects the brain. No brain, no effect."
** Pretty much the exact same thing, with different {{phlebotinum}}, happened in TheMovie.
* An episode of ''WesternAnimation/InvaderZim'' had a power amplifier that "radiated pure stupid" when [[TheDitz GIR]] hooked himself up to it.
* In the ''WesternAnimation/ReBoot'' episode "Enzo the Smart", Enzo messes with the clock speed of Mainframe in an attempt to make himself smarter. He asks it to make him twice as smart as everyone. Instead of becoming smarter, everyone else becomes [[LiteralGenie half as intelligent]] as him.
* [[WesternAnimation/TheSimpsons Homer Simpson's]] stupidity isn't natural: a crayon lodged in his brain takes 50 points away from his previously average IQ.
** This is worsened by the fact that the nuclear power plant where he works doesn't use proper shielding. All the slapstick violence in the form of blows to the head certainly can't help, either. WordOfGod is that he loses 5 IQ points a season from brain damage, and at this point he's basically "a dog that can talk."
* Used as a brief gag at the end of one episode of ''WesternAnimation/BuzzLightyearOfStarCommand''. RobotBuddy XR has had files he's not supposed to have on his brain chip throughout the episode. At the end he deletes them. However, he also erases most of his IQ by mistake.
* Played with in an ''I.M Weasel'' short on ''WesternAnimation/CowAndChicken'', in which [[ButtMonkey I.R. Baboon]] managed to publish a book that apparently turns everyone who reads it into complete and utter idiots. Lamenting on this turn of events, I.M. Weasel decides to expose himself to the "stupid powers"... but remains unaffected. He eventually realizes that everyone around him was already a stupid twit and he just didn't notice it.
* ''WesternAnimation/LiloAndStitchTheSeries'' has Experiment 319, named Spike, who can spray spikes that raises peoples' silliness by 99%, leaving them only 1% clever.
* In ''WesternAnimation/ThePenguinsOfMadagascar'' episode "Sting Operation," the penguins use one of Kowalski's inventions to make themselves stupid [[spoiler: so that they can't feel the hornet's stings.]]
** In another episode, Kowalski's attempt to boost his intelligence backfires and makes him stupid instead.
* [[WesternAnimation/JohnnyTest Susan and Mary Test]] built an intelligence amplification machine, and Johnny used it to give them an IQ of 22.
* ''WesternAnimation/{{Dogstar}}'': In "Mensamania", Fenwick creates a stupidity virus which Bob santino unleashes on Mensa, the most intelligent planet in the galaxy as a test run. If it works there, he intends to use it on Earth to make the population stupid enough to buy his latest product.
* In ''WesternAnimation/TeenTitansGo'', Beast Boy becomes sick of being the team's idiot, so he steals Raven's spellbook to make himself smarter with magic. When he screws that up, he realizes that to have a similar effect, he can just make everyone else on his team dumber than he is. He succeeds at that, but becomes frustrated with having to take care of four people who are bordering on TooDumbToLive. He decides to fix the dynamic... by making himself even dumber than his brain-drained teammates.
* ''WesternAnimation/XiaolinShowdown'' features the [[StupidityInducingAttack Woozy Shooter]], whose effect consists of creating a mist that makes its targets [[MushroomSamba hallucinate]] and act madly goofy.
[[/folder]]

[[folder:Real Life]]
* [[AlcoholInducedIdiocy Ethyl alcohol]].
* Sleep deprivation.
[[/folder]]
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