Tinfoil Hat

Thought control rays, psychotronic scanning
Don't mind that, I'm protected cause I made this hat

"I seem to recall it was your bright idea to spend billions of credits on those orbiting mind-control lasers!"
"How was I to know that tinfoil hats would become the latest fashion?"
Plan 7 of 9 from Outer Space

When a writer wants to establish a character as a Conspiracy Theorist, a Crazy Survivalist, or another kind of paranoid weirdo, they usually give them hats made out of tinfoil to wear, ostensibly to protect themselves from The Government's Mind Control rays.

As The Other Wiki can tell you, however, aluminium actually has very little shielding effect and covering just the top of the head with it leaves the rest of the body (including the bottom of the head) "unprotected", anyway. (In fact, if improperly made, the tinfoil could amplify any radiation reaching the head.) So whoever is wearing it must be... funny in the head to begin with. Or the more sinister interpretation: the whole idea that tinfoil will protect you is Just What They Want You To Think.

To elaborate: To shield off radiation, you need steel. Electromagnetic waves consist of alternating areas of electric fields and magnetic fields. To reflect them, you need a material, that shorts both electric fields and magnetic fields. In terms of shorting electric fields, any metal (being conductors) does an adequate job (aluminium (which so called tinfoil is usually made of, despite its name) is even a very good conductor), but to short magnetic field you need a ferromagnetic metal, like iron, nickel or cobalt. As iron is seldom used nowadays, the best choice is steel (an alloy of iron,carbon and tiny amounts of other components). Just take a look at a video-recorder: Videorecorders may have fancy chassis made of aluminium, but if you look inside, you will see a small box behind the coaxial connectors, there the aerial is connected, containing the high frequency circuitry. This box is made of steel in order to shield the radiation.

For when a Tinfoil Hat actually does protect the Properly Paranoid wearer, see also Artistic License Nuclear Physics and Fantastic Radiation Shielding. This trope includes both properly paranoid and simply paranoid examples.


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    Film — Live-Action 
  • Most of the main characters in Signs wind up wearing one at some point before the end of the movie. The scene gets parodied in Scary Movie 3
  • More of a hat in spirit, in Series 7: The Contenders, the ceiling of competitor Franklin's trailer is lined with tinfoil, and his personality follows suit (YMMV on whether it's played straight—along with the rest of the movie).

    Film — Animated 
  • The Futurama movie Into the Wild Green Yonder featured a cult-like group of hobos called the Legion of Madfellows who all wore such hats to prevent the Dark One from reading their thoughts, and indoctrinated Fry into their practices.note  They were, of course, Properly Paranoid. The hat also serves to block Fry's own mind reading powers as he can't turn them off of his own accord.

  • In the early Artemis Fowl books, the paranoid centaur Foaly always wears a tin-foil hat. In the second book he throws it away in frustration after being trapped in his own hermetically sealed command center.
  • The novel Idiots In The Machine by Edward Savio portrays a character who believes that tin foil keeps harmful gamma rays away and becomes a media sensation, marketing a successful line of foil hats to Chicago.
  • In The Dark Tower, Randall Flagg has one of these. Allegedly, it actually works against most forms of mind control magic, but it doesn't work on the villain he's facing, Mordred.
  • Inverted in The Salvation War, where demonic mind control and illusion powers can be blocked by foil and the story gets much mileage out of this, including the line "There will always be eccentrics who deny that the tin foil hat is absolutely essential to prevent baldricks taking over your mind."
  • In The Alloy of Law, because of the way the magic system works, aluminum blocks emotional allomancy, so wearing a tinfoil hat can in fact protect you from mind control.
  • In the Pegasus trilogy, one character wears a metal skullcap to block out mind-reading. This is actually effective against telepaths in this 'verse. Doesn't help much if the psychic has made skin-to-skin contact, though.

    Live Action TV 
  • Eastenders character Joe Wicks was briefly portrayed constructing and wearing his own tin-foil hat as part of a storyline which saw him suffering from schizophrenia.
  • In an episode of Stroker & Hoop entitled Tinfoiled again (a.k.a. Star Crossed Livers), Stroker wore a tin foil hat to protect himself from being psychically manipulated by Ron Howard.
  • In The X-Files, The Lone Gunmen wear them occasionally. Also, a policeman suggests they all get one in their Origins Episode when he realizes what kind of kooks he is dealing with.
  • On an episode of Fringe Walter wears a tinfoil hat at Massive Dynamic headquarters to defend against mindreading/Mind Control projects, and convinces Astrid to do the same. In context, it's actually a credible concern.
  • NYPD Blue: While on desk duty Sipowicz gets a call from a psychotic Conspiracy Theorist. Sipowicz suggest (in as close to Sincerity Mode as possible) that he make a tin foil hat in order to block the rays the government is allegedly sending to his head.
  • In an episode of The Finder the Finder wears an aluminum foil hat. The client (Hodgins from Bones) mocks him, but it really does help block the government from interfering with your brain waves so you can move.
  • In the fourth season of Farscape a Sheriff (or deputy) encountered by Moya's crew when they land on Earth in 1985 via time travel turns up again showing off a tinfoil-lined baseball cap on TV in 2003 when the crew returns. In his defense, he did receive several doses of one of Noranti's potions during the first visit.
  • Oliver does this in Hannah Montana, but it's really more of a parody, because he wants Joanie to think he's insane and dump him.
  • Dollhouse: Senator Perrin goes public accusing the Rossum Corporation of unethical practices, hoping that it will encourage witnesses to come forward. The following episode he's griping that the only witness so far is a guy in a tinfoil hat claiming that Rossum mailed his liver to Saturn.

  • Deconstructed in Freemans Mind, where Freeman reasons that, assuming mind reading is possible despite not showing up on any known spectrum, a tinfoil hat would conduct any signal that the wearer is concerned about. He concludes that you'd have better chances with a lead helmet coated in rubber.

  • In Doctor Steel's web video, "Reality Engineering", Steel is shown wearing a tinfoil hat when he's labeled a conspiracy nut.
  • "Weird Al" Yankovic's "Foil" (which provides the trope picture and is a parody of "Royals" by Lorde) has Al claim to have cracked the code on conspiracy staples such as the Illuminati, Black Helicopters, the Moon Landing Hoax, and more, which is why he crafted a handy hat from foil, to protect himself from alien Anal Probing and mind reading. It doesn't do him much good, because The Men in Black just tranquilize him and drag him away.

    Tabletop Games 
  • GURPS Illuminati actually gives a bonus on resisting Mind Control Lasers to people wearing a tinfoil hat.fnord 

    Video Games 
  • The tin-foil hat was an April Fool's Day item created by Blizzard to parody player paranoia about their character information being searchable on the World of Warcraft armory.
  • L.A. Noire features a street mission in which Phelps has to chase down a tinfoil hat-wearing conspiracy theorist.
  • Dogen Boole in Psychonauts wears a tinfoil hat he claims prevents him from accidentally making people's heads explode with his Psychic Powers.
  • In Destroy All Humans!, you occasionally encounter humans wearing tinfoil hats... and Crypto can't read their minds because of it.

    Web Comics 

    Web Original 
  • SJ Games used to (still does?) run a site cataloging weird things you might find in a Secret Government Warehouse. One of them was a crate of instruction booklets on how to make a tin-foil hat. They were all stamped "obsolete" and there was a note in the inventory saying that the mind-control system had been upgraded since printing, so tin-foil hats were no longer effective. (Elsewhere in SJ Games's paranoia-inducting line of games is the note that aluminum foil beanies do not work against mind-control devices, but tin foil beanies did. This fact is behind the switch from tin to aluminum foil in the mid-20th century.)
  • A guy wearing a tinfoil hat is the symbol of the Wild Mass Guessing section of This Very Wiki.
  • The Aluminum Foil Deflector Beanie.

    Western Animation 
  • Exaggerated in an episode of The Simpsons, "Brother's Little Helper", Bart becomes paranoid after taking an ADD drug called Focusin, leading him to believe that Major League Baseball is spying on him and begins donning a tin foil bodysuit. At the end of the episode, Bart turns out to be right when he shoots an MLB satellite out of the sky.
  • On Regular Show, Mordecai and Rigby make foil hats when using Pops' '80s era cell phones, after he warned them that they cause tumors.
  • Being a paranoid cuckoo girl, Sticks of Sonic Boom inevitably references this in "My Fair Sticksy". She mentions one of her town defense system modes includes people trying to read her thoughts. According to her, it's a serious of tinfoil-lined paddles to smack away telepathic signals. Or maybe just smack the mind readers themselves.
  • In The Amazing World of Gumball, Mr. Small wore this when he says he's aware of many things in Elmore disappearing like Janice. It turns out he was right when Gumball and Darwin noticed Molly was missing and they all went to the Void to rescue her and Janice. Tinfoil hats were worn so they are aware of the existence of the Void and at earlier times, change one's luck like in "The Helmet".