Everyone has their own view of the world and what happens around them. Maybe Bob believes that Humans Are Bastards. Maybe Alice thinks Chris is going to betray her. Given enough time, though, these views and opinions can change, allowing Bob to see the good in people, and Alice to start to trust Chris. This trope is when that never happens; A character suffering from Theory Tunnel Vision will stick with whatever idea they have for way longer than what would be normal. Even if Bob meets hundreds of Good Samaritans, he'll keep stating that Humans Are Bastards and Alice will never trust Chris even though he saved her life several times now.
There are several kinds of Theory Tunnel Vision, and several reasons for someone suffering from it:
- Pride/stubbornness: Bob is just too proud or stubborn to say that he's been wrong, instead keeping up his own version of reality.
- Familiarity/indoctrination/prejudice: Bob has been told every day of his life that group X is evil. As a result, nothing group X will ever do can change Bob's vision. Even if someone from group X would rescue Bob from a burning building, all he'd say is to let go of him.
- Convenience: Bob believes whatever is the most convenient for him. If he hurts Alice, he'll rationalise it after the fact: she must have done something to deserve it. If his friends are prejudiced against group X, he'll convince himself that group X is evil, just so he can fit in with his friends without feeling bad about not calling them out. If he throws someone under the bus to save his own skin (or reputation) or gain favor with someone else, he'll convince himself that he had no other choice. In short, Bob will change his memory of events to fit his perception of himself as the good guy and protect his ego.
- Hostility: Bob has a certain view of the world. Alice, his nemesis, states that he is wrong and has a lot of evidence to support her. However, since Alice is Bob's nemesis, he has no reason to believe her, even if the evidence is groundbreaking.
- Trust: Bob simply cannot believe that Alice would ever do something bad; even when she steals money right out of his hands, he deems it an accident. This one pops up very often with parents towards their children.
- Broken Trust: Bob has been betrayed so many times in his life that he simply cannot believe that someone would ever do something good. Even if Alice helps him pay his monthly bills, he sees it as a way to get him in debt with her.
- Mental disorder: Due to a handicap, Bob believes that whatever he thinks is true, is in fact true; anyone who states otherwise is deemed a liar.
- Sunk Cost Fallacy: This may overlap with others. Bob has used up too much time/effort/money/etc acting on a specific belief. If he admits he was wrong, all of that would be wasted.
Theory Tunnel Vison can be both positive and negative, and the person suffering from it can be proven right in the end. The key point is that someone who suffers from it will discard any and all evidence that proves them wrong, no matter how solid it is.
If someone suffering from Theory Tunnel Vision at some point does break, expect a Heroic BSoD, along with muttering about how this should be impossible. A fair warning, though: Do not try to break Theory Tunnel Vision on purpose, as there is a good chance that you'll lose your friendship with the sufferer... or worse.
Selective Obliviousness is the supertrope of this; Flat-Earth Atheist and The Scully are subtropes. A staple technique of the Tautological Templar. The Fundamentalist is the logical extreme of this, building everything around a few notions held this way. What develops into Theory Tunnel Vision may start out as Aggressive Categorism. Also compare I Reject Your Reality, Psychological Projection, and Self-Serving Memory.
Truth in Television; even normal, non-neurotic people will take considerable evidence to overwhelm a strongly-held theory, let alone those in psychological denial who'll get angry at people pointing out reality.
- Though the supernatural is Invisible to Normals in Ayakashi Triangle, even people who can't see can overcome the Weirdness Censor to be aware of its existence. However, once Lu falls in love with someone she thinks is an alien, she is thoroughly convinced anything that seems supernatural actually involves aliens or nonsensical pseudoscience, and constructs elaborate, bizarre alternate theories when magic and spirits are starring her in the face.
- Death Note: Light Yagami is firmly convinced that he's a good guy and that everything he does as Kira is necessary to create a better world, and refuses to see that his actions make him no better than the criminals he's trying to rid the world of. Heaven help you if you so much as suggest that what Light is doing is evil.
- Dragon Ball Super: As far as Zamasu is concerned, all mortal life is evil and needs to be destroyed, and the gods, while lazy, are inherently perfect. He blindly refuses to consider the possibility that mortals can learn and grow from their mistakes and that the gods are just as fallible, even when Gowasu tells him as such.
- In Kill la Kill, Ryuko comes to believe that Student Council President Satsuki Kiryuin was responsible for her father's death before the start of the series since Satsuki claims to have knowledge about why it happened. She becomes so fixated on this that her flashbacks from when she barely saw the killer fleeing the scene start to shift so the figure resembles Satsuki, meaning that when the real killer, Nui Harime, whose twintails make her a dead ringer for the initial silhouette, reveals herself, it comes as quite a shock to her.
- In Monster, detective Lunge initially believes protagonist Dr. Kenzo Tenma to be the serial killer. Over the course of the series, evidence that Johan is the real killer is practically thrown at him, from close acquaintances of Johan to criminal psychiatrists. However, Lunge continues to believe that Johan is a pseudonym for Tenma. It isn't until near the very end, when Lunge sees Johan with his own two eyes, that he realizes Johan is a real person.
- Played for tragedy in Your Lie in April. Early on, it is shown that Kousei's late mother Saki once beat him bloody for underperforming at piano, causing him to wish she was dead. Later, we see the same event from her point of view, where she confesses to a close friend that she pushed him to abusive extents because she was terminally ill and convinced that piano mastery was the only way he could make a living after her passing. Whether this puts a sympathetic sheen on a secretly-broken woman's tough love or just makes her more monstrous for being blind to any other ways Kousei could have gotten by remains one of the divisions in the fandom.
- The Daredevil comic "Seventh Circle" has him run into The Punisher during a Russian gangster's high-profile trial that Matt Murdock is trying to move to Texas since it'd be impossible for the gangster to get a fair trial in New York. Frank is convinced Matt is trying to get the trial held in a state where the death penalty applies and calls Matt a killer, one using a jury rather than a gun... to Daredevil.
- Doctor Doom simply cannot get it out of his head that Reed Richards was responsible for the accident that disfigured him. Being something of an egomaniac, he naturally assumes Richards thinks like him, and occasionally designs traps that would be impossible for Doom to escape... and that Richards just strolls out of.
- Hugo Strange projects his many, many neuroses onto Batman, certain that he only fights crime because he gets off on beating weaker people (Strange being a short, glasses-wearing psychiatrist who occasionally dresses as Batman).
- J. Jonah Jameson is convinced that Spider-Man is a threat and a menace, and no matter how many acts of heroism Spider-Man performs, nothing will change his mind. One story shows that his distrust comes from his abusive upbringing by his veteran father, which soured him on the idea of heroes.
- Many depictions have Jameson utterly fixated on the idea that anybody who wears a mask to hide their identity must have nefarious motives. After all, police don't wear masks but bank robbers do. He refuses to acknowledge that the existence of supervillains far more dangerous than ordinary criminals means that superheroes have an actual legitimate reason to hide their civilian identities.
- The reason Lex Luthor has never figured out Superman's secret identity and never will barring certain extreme circumstances (such as at the end of The Black Ring where he became omnipotent and was able to view Supes' past) is because he is absolutely certain that Superman is an evil mastermind just like him, who would never bother wasting time with being an ordinary journalist like Clark Kent. One comic has him hire a computer expert who uses facial recognition software to point out the obvious Clark Kenting. Lex responds by firing her because obviously Superman wouldn't "stoop" to being Clark Kent and so her software must have something wrong with it.
- Watchmen: When Rorschach investigates the Comedian’s murder, he comes to the conclusion that someone is specifically targeting superheroes based solely on a hunch. As he tries to investigate further, he stubbornly ignores more obvious and logical answers in favor of his “mask-killer” theory. As a result, he spends most of the story on a wild goose chase and by the time he finally figures out the true scale of what has happened, it's too late to do anything about it.
- In Avengers: Infinite Wars, Dooku begins to basically speculate that Palpatine is a victim of this, as Darth Sidious continues to focus his efforts on trying to return to his original plans for the Clone Wars, rather than work on adapting his plans to properly incorporate the Avengers and Ultron and their impact on his schemes (such as Anakin spending more time with the Avengers and thus limiting Palpatine's opportunities to corrupt him).
- After she's replaced in Burning Bridges, Building Confidence, Alya immediately leaps to the conclusion that Vexxin must have stolen the Fox Miraculous, quickly banging out a blog post accusing the new heroine of being a thief. When Lila spins her own sob story about what supposedly happened, Alya's willing to listen since she's 'Ladybug's friend'... but it's not long before her anger gets the better of her, and she dismisses everything that doesn't support her belief that Vexxin must have stolen the Fox.
- This is effectively Alya's Fatal Flaw: despite claiming that 'a good reporter always checks her sources', in practice, she sees no need to do so once she's set her mind on something. This makes her an ideal pawn for Lila, who transforms her from Marinette's best friend to her personal one-girl attack crew.
- This flaw is prominent in many other Post-Chameleon salt fics where Alya is presented with hard evidence against Lila's lies and her own erroneous theories but she doesn't believe it.
- Henrietta Garland from Catarina Claes MUST DIE! is the reincarnation of a bullied girl that found relief watching Fortune Lover Hate Sink bully Caterina Claes die in the bad ends. So when she is reincarnated in the world of My Next Life as a Villainess: All Routes Lead to Doom!, she remains firmly convinced that Caterina is a villainess who should end in doom, despite evidence that Caterina is now a Nice Girl thanks to regaining memories of her past life. For example, when hearing how Caterina is treated like a beloved Saint, Henrietta is convinced that she is really a Bitch in Sheep's Clothing that secretly bullies her adopted brother Keith and the commoner student Maria when in actually the latter two are among Catarina's loved ones.
- In Dæmorphing: The Herdmoot, Arbron's parents assumed he died years ago when his Guide Tree went dormant. After learning he became a Taxxon nothlit, they still think he died years ago and another Taxxon is pretending to be him in the present because it's easier than accepting that Taxxons are people.
- Flat out lampshaded in Girl Days where Kunou, Ryouga, and Mousse are all mentioned to "take the facts and jam them into their viewpoint."
Author's Note: The astute reader will notice that Ryouga Hibiki has what can be best described as an unusual logic system. Rather than going from facts to conclusion, one starts at the conclusion and jams the facts around it. And in the minds of the likes of Ryouga Hibiki and Tatewaki Kunou, we all KNOW what the conclusion is.
- The GIW meets its match: The Guys in White are so convinced that ghosts are Always Chaotic Evil and non-sapient that they ignore all evidence to the contrary, relying upon Doublethink-laden "logic" to justify their stance. They also firmly believe that it's outright impossible for anyone who isn't a ghost to oppose them, as their cause is so "obviously righteous"; thus, they assume anyone who resists their extremism is either a ghost in disguise or secretly being controlled by one.
- In Infinity Train: Wake Me Up, there's something of a running theme of characters coming to a conclusion about how other people are or "should be," and treating them accordingly no matter the evidence.
- Amanita was not impressed when Parker began flirting with her shortly after they met. She promptly handed him an Eevee as a blatant bribe to go away and doesn’t bother hiding her disdain going forward. At one point, she expresses sincere sympathy for Jinny when she learns that the other girl was having a sleepover with Parker. In actuality, Parker is a perfectly friendly five-year-old and hasn't been shown flirting with anyone except Amantina.
- Blake and Whitley actually have something of a mutual example going. Blake is absolutely determined to arrest Whitley based on her past as a Team Plasma member, with no regard for what she's done to try to atone in the intervening years. In the process, he makes himself look like such a jerk that Whitley holds him in contempt, and Trip chose to interfere with his ambush five minutes after meeting Blake, without considering that the Interpol agent might have decent reasons to arrest Whitley.
- Eventually, this becomes a major plot point: the Vermillion Citadel's motive is born out of the belief that Chloe Cerise must be one of the Train's greatest heroes. Being composed of "Chloes" from across the multiverse, they (ironically enough) have a checklist of traits that they believe "Chloe of the Vermillion" must possess. They are willing to resort to kidnapping, blackmail, and tormenting innocent people just to push Chloe into becoming a famed hero- only for most of their plans to fail because this Chloe is a lot closer to her anime incarnation. She is not a Nightmare Fetishist, being Properly Paranoid at someone handing her a "demonic artifact," is actually afraid of dogs, and hence never traveled with Atticus, and while she was eager to transform with a Miraculous, she does about as well against a rampaging monster as you might expect from a ten-year-old with no combat training.
- Invoked in Lost in Camelot, when Arthur learns that Bo, Merlin, and Morgana are in a triad relationship and ask how they intend to keep their relationship secret from Uther. Since Uther believes that Morgana's involvement with Bo is basically just them indulging a youthful interest, and he is also convinced that Merlin is involved with Arthur, Morgana doubts that Uther will properly register anything that contradicts that perspective for a while at least.
- The Moon Cries in Reverse (Naruto): Played for Drama in Lunar Lamentations. Once Anko got it into her head that Naruto, Sakura and Shikamaru might not be too terribly loyal to Konoha due to how badly Naruto and Sakura were bullied and Shikmaru's intelligence reminding her too much of Orochimaru, she views literally everything her genin team does as "more evidence" of how dangerous they are. Even worse, Ibiki and Hiruzen share her beliefs, leading them to extreme ends to try and nip the supposed issue in the bud... and potentially creating a Self-Fulfilling Prophecy in the process.
- In Pokemon: Shadow of Time, Ash has rejected the idea of dating any of his travelling companions because he doesn't want to abandon them like he believes his father did, ignoring how even his Pokémon are aware that the girls would be willing to follow him on his travels.
- RainbowDoubleDash's Lunaverse: The Element Bearers are utterly incapable of seeing Corona (also known as Celestia) as anything but an arrogant, cruel, greedy monster who'd kill them all given half a chance. This backfires when they're forced to work together, and the six of them think backstabbing the Physical God who's agreed to work with them is a better idea than stopping the necromancer who's trying to become immortal. In fairness, though, they're part of a culture that's been fed a thousand years' worth of stories about how evil she is, and when they first met, she kidnapped some of their loved ones, on account of being completely insane. But even after she's cooled down somewhat, they still refuse to think she's not pure evil.
- Shadows over Meridian: Caleb is so convinced that Jade/Kage is a minion of Phobos and "the Mage"/Nerissa was a genuine ally of the Rebellion that he refuses to acknowledge any evidence to the contrary and relies on increasingly convoluted theories to justify his viewpoint. Even the Guardians rebuking him, his father trying gently to talk sense into him, and Elyon herself chewing him out for clinging to his paranoid beliefs can't get him to drop them.
- Two Letters: After Marinette retires, Alya swiftly decides that the new Ladybug must be to blame — somehow, she must have forced Marinette to give up the Earrings! And that's also why Marinette has been avoiding her best friend! In reality, Marinette willingly gave up her position, and is avoiding the would-be Intrepid Reporter after Alya betrayed her trust one too many times. It takes being told this point-blank for Alya to even consider the possibility that her theory was off the mark, and she still tries to nudge Marinette into confirming her version of events.
- In The Undead Schoolgirl: Dead Pulse, one of Todoroki's first interactions with Izuku and Katsuki convinces him that the latter is abusing the former due to them reminding him of his parents. Afterwards, everything gets viewed through that filter no matter how much it contradicts his theory. Inko isn't worried about Katsuki abusing her daughter? She must not care about Izuku. Inko then freaking out over her daughter getting hurt? She must not know about Katsuki's abusiveness. Katsuki blatantly places Izuku's safety above his own during a villain attack? He's just trying to make himself look good to her. Izuku showing absolutely no fear of Katsuki and even berating him at times? She only feels safe because Todoroki is present.
- 22 Jump Street: Discussed and leads to an "Eureka!" Moment. While chatting with a therapist about their partnership issues, the therapist tells Schmidt and Jenko about embedding and how people latch on to the first bit of information that they're offered while ignoring anything contradictory. This causes the duo to realize that they've been basing their whole investigation on Captain Dickson's briefing that the victim was buying the drugs when in truth she was the one selling them.
- The Caine Mutiny: This is ultimately what exposes Captain Queeg’s mental issues; after a quart of strawberries goes missing from the ship’s galley, Queeg then becomes convinced that there’s some sort of dangerous and recurring food theft going on, concocting an elaborate vision of the “heist”. He soon forces the crew to practically turn the ship upside down in search of a duplicate key that exists only in his imagination and when he’s directly told what really happened (a couple of mess boys ate the strawberries as a snack), he simply ignores it and continues his investigation, to the point that his XO finally relieves him. He ends up damning himself in the court when he goes on a paranoid rant about the strawberries while on the stand, undoing all of the prosecution’s work in proving a mutiny and making it clear that Queeg truly wasn’t in a fit state of mind.
- The Covenant: Chase believes that he can overcome the rapid aging caused by overuse of the power if he gets Caleb to give him his own power to boost his energy, even though Caleb tries to explain to Chase that the issue is the body wearing down rather than the power.
- Sherlock Holmes (2009): Holmes and Watson discuss this trope, in regard to Lord Blackwood's apparent resurrection from his execution. Watson, having seen his fair share of weird shit during his military career, suggests that this time the case could have genuine supernatural elements to it. While Holmes is open to the possibility, he also warns Watson to wait until they have all the facts first, similar to his MO in the Literature section below. "Inevitably one begins to twist facts to suit theories, instead of theories to suit facts."
- A woman suspects her husband is cheating on her. She takes advice from her friends, who tell her to look for Affair Hair. When her husband comes home and she can't find any, she's horrified and disgusted — her husband is cheating on her with a bald woman!
- A joke frequently told during the late 20th century in areas under military occupation has the driver of a Volkswagen Beetle pull over at a military checkpoint. He starts to open the front hood,note but the soldier says "What do you take me for? An idiot?" So the soldier has the driver open the vehicle's rear, and says "Aha! You have stolen a motor! And you must have just stolen it, since it's still running!"
- The Chronicles of Narnia: In The Last Battle, Dwarves are in paradise eating a feast, but they believe they are in a hut eating slops. This does at least have a mystical explanation, as it is caused by Aslan's power, and is part of Lewis' Author Tract on how atheists could have God and Heaven right in front of them but be unable to see it.
- Mentioned by the narration in the Father Brown story "The Absence of Mr Glass", when a criminologist consulted by Father Brown attempts to explain the case in terms of his own theories based on racial characteristics.
A man warmly concerned with any large theories has always a relish for applying them to any triviality.
- Forgotten Realms: Something of a recurring theme with guards in Ed Greenwood's novels, who seem to be prone to theorizing that anyone at all they don't personally know and who wants to get past them is up to no good and therefore needs to be brushed off, arrested, or simply killed outright. A classic example in the "Shadow of the Avatar" trilogy has the protagonists come back from a patrol for the Lord of Shadowdale and be accosted by guards of the Lord of Shadowdale, who casually dismiss all their claims and seem all too eager to engage in some casual bloodshed for their own amusement (to be fair, those particular guards were newly hired, but still).
- In Ground Control to Psychoelectric Girl, Erio was in a tragic accident wherein she went missing for three months and then turned up on a beach without any memory of the intervening time. Her reaction was so bad that she invented a story that she had been abducted by aliens and convinced herself that was the only explanation. After a few months, she tried to test her theory... only be injured again. But again, because she was far too fragile to face reality, she only drew even further into her fantasy world, to the point of becoming a Hikikomori. Later, her cousin forcibly proves to her that she isn't an alien, but after an initial highly negative reaction, she seems oddly okay and is even willing to regain society again.
- In Harry Potter, the eponymous character is dead set on blaming anything and everything that goes wrong at Hogwarts (that isn't obviously Voldemort's fault) on Severus Snape or Draco Malfoy, his two main bullies. Sometimes he does have a reason to be suspicious, like in the first book where he stumbles on Snape threatening Professor Quirrel at night and later sees that Snape got bit by Fluffy, the guardian of the book's MacGuffin. Other times, he just wastes time and gets himself in his friends in trouble running after false leads, like when he and Ron use Polyjuice Potion to subtly interrogate Malfoy about the 'Heir of Slytherin' who's been petrifying students... only to learn that while Malfoy approves of the Heir's activities, he has about as much clue about the Heir's identity as Harry does. This goes full Dramatic Irony in book 6, where the reader knows that Draco has been given a mission from Voldemort and Snape has sworn an Unbreakable Vow to help him, but Harry doesn't and drives his friends up the wall by suspecting Draco anyway for all the wrong reasons.
- In The Rook, Graf Gerd De Leeuwen is so fixated on the idea that the Checquy have his missing brother in custody that he ignores Myfanwy's protests that they don't actually know where his brother is (as it turns out, the Graf was right, but even the Checquy didn't know that they had the brother in question).
- Sherlock Holmes believes guesswork leads to this, refusing to discuss a case before he has all available data. He often has multiple theories before finding that out, going on what the newspapers say, but these are inevitably discarded before the end.
- Frequently played for laughs in Suppose a Kid from the Last Dungeon Boonies Moved to a Starter Town, where much of the comedy involves various characters being Entertainingly Wrong about outlandish circumstances or contrived coincidences. For example, Selen believes that Lloyd's love for her unlocked the cursed belt that covered her face all her life. From there, she also assumes that love is the man she's destined to spend her life with and, when the belt turns out to also be a magical artifact that protects her from any harm, that it has been blessed and thus represents the strength of their destined love. Whenever evidence or a person contradicts any level of this logic, Selen will either dismiss it, add a new insane theory, or just flat out murder/destroy whatever's causing the contradiction.
- In the Buffy the Vampire Slayer episode "I Only Have Eyes For You", Giles is initially convinced that a haunting is Jenny trying to communicate, despite all evidence to the contrary, until he is forced to accept that Jenny would never be as cruel as the ghost they're dealing with.
- Dexter: Multiple times throughout the show, a character will suspect something is off (to the point of a Cassandra Truth) and Dexter will have to invent evidence to turn them away. It often works. One extreme example when it doesn't is when Laguerta adamantly believes that Doakes is innocent. No matter what evidence Dexter plants to the contrary, she still stands by this belief.
- A regular feature of Doctor Who.
- The Doctor arrives in a situation, announces that what's going on is nothing like what the local authority figure believes, and is immediately worked into the authority figure's theory as being part of the problem. However, the Doctor has been known to suffer from tunnel vision themself, for instance in "The Curse of Peladon", where the Third Doctor finds it hard to believe the Ice Warriors aren't the baddies.
- The Twelfth Doctor, who despises war and killing and hates himself for hurting innocent people, cannot believe that Clara's ex-soldier boyfriend Mr. Pink is anything but a Blood Knight who glories in death and destruction. Mr. Pink, now a middle-school teacher who also despises war and killing and hates himself for hurting innocent people, upon learning the Doctor is a Time Lord, cannot believe that an officer ("an aristocrat!" at that) is anything but an Upper-Class Twit Glory Hound who doesn't care about "lower people" getting hurt. In the end, they agree that Clara loves them both and that's all that really matters. (The Doctor also settles on referring to Pink as a muscle-headed PE teacher [Pink teaches maths], which is probably an upgrade from heartless killer soldier.)
- In the Elementary episode “The Deductionist”, FBI profiler Kathryn Drummond notes that she has profiled various serial killers and found them all to be the victim of childhood sexual abuse. However, this led to her forming the same view of killer Martin Ennis, to the extent that she paid an old neighbour of the Ennis family to provide fake testimony confirming such abuse rather than just admit that she was wrong about him, which drove Ennis’s father to suicide and his mother dying of despair a year later.
- Kamen Rider Gaim:
- Takatora tends to have tunnel vision on multiple fronts, like believing his co-workers are good friends (they're actually conspiring against him) and that they need to sacrifice six-sevenths of humanity to save the rest. He doesn't like that last one, but is so convinced of it that he tries to break Kouta's spirit to assuage his own guilt (after all, if he can convince an idealist that it's the right course of action, it must be). Kouta eventually manages to bring him evidence solid enough to convince him that less deadly solutions are possible, but he doesn't catch on to his co-workers' betrayal until they flat-out try to murder him.
- Unfortunately, his little brother Mitsuzane also has tunnel vision, and (combined with being a Heroic Wannabe) his ends up being far more destructive. In his case, the belief he can't let go of is "I'm smart and logical, and I can get us out of this situation." When Mai tries to counter some of what he says, he decides she must be confused. When Kouta deviates from the long-term plans with short-term heroic actions, Mitsuzane gradually becomes convinced that he's a naive idiot who needs to be killed for the good of everyone else.
- Monk has an episode with a nudist. Since nudity is one of germaphobe Adrian's triggers, his theories get crazier and crazier as he tried to explain how the nudist has to be the guilty party.
- Genius: The Transgression: A Genius's Wonders are based on forming a theory that doesn't fit reality and then crazying it into working anyways, so naturally this is a common problem amongst the Inspired. A Genius who comes to truly believe that his Wonders describe reality instead of altering it to function is called an Unmada. Unmada make up the Lemuria faction, and the Etherite branch of the Lemurians are a textbook example of the trope; they are Inspired who latched on to some scientific or pseudo-scientific theory (a common one being the Luminiferous Ether, hence their name) and now absolutely refuse to acknowledge any evidence that disproves it and get very violent when their pet theory is questioned.
- Paranoia: After the Big Whoops, when The Computer was trying to figure out what the hell to do next, the first usable files it found were civil defense files from 1957. It promptly decided that Alpha Complex was being invaded by the Commies, and rejected all evidence to the contrary as an elaborate Commie plot to obscure the truth.
- Warhammer 40,000: Part and parcel of the Crapsack World nature of the setting, since the Imperium runs on fundamentalism and rigid discipline. One reason Ork kommandoes (seven-foot-tall killing machines who are stealthy and able to perform covert missions in addition to being the charge-happy dakka-shooting lunatics we know and love) are successful is that a Guardsman who tried to report their existence was executed for cowardice, as what he said went against Imperial doctrine.
- The Batman: Arkham Series version of Riddler is so convinced that Batman is nothing more than a thug that bullies those weaker than him and that his tech is stolen from others, that after Scarecrow removes Batman's mask in live television, Nigma refuses to believe it and "figures out" that the entire thing was a conspiracy created by Batman, Scarecrow, and most of the human populace just to trick him.
- Played for laughs in the Hordes of the Underdark expansion for Neverwinter Nights — if you have Deekin with you in Hell, he interprets the signs of battle between Demons and Devils as the remnants of something long and complicated involving dragons.
- In Red Dead Redemption II, it's subtle but almost every time a major job goes wrong, the gang automatically assumes there was a mole, no matter how improbable. The Saint Denis heist is a great example, as the gang normally goes south or east to evade the law, so it wouldn't be a stretch for the law to guess Saint Denis would be their next target. Some gang members also take certain circumstances, such as Abigail being able to escape when Hosea didn't or John being captured but not killed right away, as evidence of them being traitors. It isn't until the end that Arthur realizes how flawed their strategy is. Of course, there really is a mole, but they didn't turn traitor until after Guarma.
- Walker in Spec Ops: The Line is always certain that he's doing the right thing and that the 33rd are in the wrong, despite the mounting evidence to the contrary. He finally recognizes the truth at the end of the game.
- In Super Paper Mario, upon hearing that Mushroom Castle was attacked and Princess Peach was kidnapped (AGAIN!), Luigi immediately decides that Bowser must've been behind it. (He would have been right the last fifty times...)
- In Ace Attorney, Miles Edgeworth's initial approach towards prosecuting was this. Unlike other prosecutors who merely wanted to win (such as his mentor Manfred von Karma), or those who only want to seek the truth (such as Klavier Gavin), Edgeworth worked on the premise that the defendant was always guilty of the crime they were accused of, and prepared his cases and arguments around that. He thinks this way because of Psychological Projection; he believes that he is a Karma Houdini for accidentally killing his father as a child and assumes that all other defendants are in the same position he was: guilty but faking innocence. His character arc in the original game involves getting over this view; it starts to crack in case 1-3 when Phoenix convinces him that Will Powers was innocent and Dee Vasquez was suspicious, and Edgeworth ends up being the one to force the critical testimony that ends the case in a Not Guilty verdict, and it falls apart entirely after he becomes the defendant of 1-4 and Phoenix proves that not only is he innocent of the original crime, he never killed his father, and Manfred von Karma taught him to believe in his own guilt because Manfred was the true murderer.
- El Goonish Shive has got those two alien enthusiast nerds annoying people. Hilariously enough, they never noticed real aliens and half-aliens in their town.
- In Homestuck, Terezi finds the corpse of Tavros and immediately concludes that Vriska is the most likely suspect. As she searches the crime scene for clues, Terezi admits to herself that she's only pretending to not already know who the murderer was. Then she finds the bodies of Feferi and Nepeta and concludes that Vriska's on some kind of killing spree. She's a bit taken aback when Vriska freely admits to killing Tavros but isn't even aware that the others died.
- Note that while Gamzee had staged the last crime scene to frame Vriska, it was only after they found out about Terezi's personal conviction, and John later remarks on how poorly staged said scene was.
- The Order of the Stick
- Tsukiko firmly believes that Humans Are Bastards, and as the opposite of the living, undead are good underneath everything, despite the total lack of evidence for this. She starts to realize she may be wrong as her wights are controlled into draining her to death.
- Miko is unable to comprehend that anyone who is good might disagree with her methodology, therefore the Order (who defend Belkar, who is evil) are also evil. Her determination to stick to this belief in the face of all the evidence eventually leads her to full-blown paranoia and falling from paladinhood when she concludes that her sworn lord since he "conspired" with the Order, is also evil... and betrays her oath by killing him. This, of course, she interprets as further evidence of the Order's evil. They "tricked" her into abandoning her vows.
- Redcloak believes O-Chul is hiding information about the defenses of Girard's Gate from him despite multiple torture sessions and every coercive spell he can think of. The fact that O-Chul doesn't know (the first five guardians of the Gates swore not to look for the gates' locations precisely in case this happened) isn't about to stop him. In Redcloak's case, it's actually a subversion: while he is baffled that the Sapphire Guard would throw away the security of the world for a foolish promise by their predecessors, he's accepted it as the truth and is using the interrogation as an excuse to hang around Azure City instead of continuing to the next Gate as per Xykon's intentions.
Redcloak: I find it far more probable that you are somehow resisting my magic. This "Soon's Oath" story is just that — a cover story designed by your leaders. [...]
O'chul: You find the idea that I have some sort of secret knowledge implanted in my brain by the elders of the Sapphire Guard that has been so deeply suppressed that no magical effect can unearth it to be simpler... than the idea that I just don't know anything?
Redcloak: I like the way I phrased it better.
O'chul: No doubt.
- In Schlock Mercenary, during the Mahuilotu arc, the local police just cannot get over the idea that the killer shark was some kind of "murder-sub" built by John der Trihs. (They knew that their terraformed planet didn't have any sharks. Why blame John? They probably figured that he who smelt it dealt it.) The Toughs later threaten to sue the idiots for what their lawyer calls "impersonating a police force".
- In Atop the Fourth Wall, Lord Vyce is completely convinced that he alone can defeat The Entity, that he absolutely refuses to believe Linkara when he says the latter already defeated it. When Linkara points out that there's video footage and sensor readings of The Entity's defeat, Vyce brushes it off as either The Entity Faking the Dead or Linkara doctoring the evidence.
- Parodied (rather darkly), with Mario Is a Monster, a creepypasta story by Slime Beast similar to his earlier I HATE YOU. The narrator is dead-set on making Mario out to be the true villain of his series by describing all his actions in his 8-bit and 16-bit games in the most heinous-sounding way possible. It gets to the point that the narrator discusses a "spooky lost game" (in typical Mario-related creepypasta style) called "Mario Nights" full of terrifying and gory content like poorly-lit Blackout Basement levels, "gibbering bogeymen", masked worm creatures that pop out of the ground only to get their pale flesh burnt by Mario's flashlight, Yoshi puking out acid, and the Nightmare Faced Big Bad eating a chunk out of Princess Peach's skull if you lose. The narrator is so focused on portraying Mario himself as a bad guy that he glosses over all the frightening stuff happening around Mario in "Mario Nights" — and is confused when no one else he talks to knows about the game.
- Sadly common in Not Always Right and it sister sites. A surprising amount of customers are absolutely certain that whatever theory they want to be true, like a store selling a certain product, an item working a certain way, or a person actually working at a store they're in, is absolutely correct and every employee/concerned bystander/police officer they meet is part of a massive conspiracy against them. This story takes it to pure I Reject Your Reality levels, as a rehab center employee would rather believe that the poster faked their driver's license, passport, military dependent ID, concealed carry permit, social security card, credit cards, checkbook, hunting license, and Facebook page, than that a person in rehab gave them a fake phone number when asked.
- In There Will Be Brawl, Mario immediately assumes Bowser is behind Peach's latest kidnapping and refuses to hear any other explanation... not that you could blame him, of course. He only relents when Luigi tells him of Bowser's death.
- Denzel Crocker in The Fairly OddParents! immediately attributes anything slightly unusual to FAIRY GODPARENTS! Granted, he is correct a lot of the time, but he is just as quick to attribute completely mundane events to them.
- In the Gravity Falls episode "Little Dipper" after Mabel Pines determines that Dipper's spontaneous growth spurt is the result of magic, she accuses him of hiding a wizard in the closet. After she opens the door to find an empty closet, she accuses him of hiding an invisible wizard in the closet. Even after Dipper shows her what the real cause of his growth spurt was (a flashlight fitted with a magic crystal that refracts light into growth and shrink rays) she still thinks there's an invisible wizard hiding in the closet.
- The Owl House: Despite having lived among them for hundreds of years, Emperor Belos still clings to the belief he was fed during his childhood, that witches and demons are all inherently evil and deserve to die. This is especially galling since the residents of the Boiling Isles were actually fairly peaceful and good-natured when he first arrived and only turned more callous and darwinistic because of his influence. Likewise, he preemptively rejects the idea that other humans (like Luz or Caleb) could and would have genuine objections to his goal of complete genocide, convincing himself that living among witches has twisted them somehow, and justifying the fact that he murdered Caleb by saying that he was trying to save his soul. When you get past the lies Belos tells himself, however, it becomes crystal clear that he murdered Caleb because he resented his brother for leaving him alone after falling in love with Evelyn, and that he now seeks to wipe out the Demon Realm out of sheer spite towards her.
- The Shredder in Teenage Mutant Ninja Turtles (2012). He claims Splinter is responsible for everything bad in his life. At first, it seems like he's just lying to manipulate his henchmen, but soon it becomes clear that he seriously believes in the bizarre conspiracies he attributes to Splinter, violently rebuking any evidence to the contrary. He clings to this theory so obsessively that he sometimes seems to be outright delusional. At one point, he sincerely claims to have watched Splinter murder somebody that he himself killed.
- Young Justice (2010):
- General Zod theorizes that Jor-El sent his son to Earth so that he would become a god among the humans, turn the planet into a New Krypton, restore the glory of the Kryptonian race and bring them to galactic supremacy (something Zod himself would've done, of course, militant jingoist that he is). Seeing that Superman has "failed" in this endeavor, Zod swears to succeed where he failed and prepares to have Superman executed by a brainwashed Superboy.
- After the Zods fail to conquer the Earth or kill either of the Els, Lor Zod uses the Time-Sphere to flee before he can be captured by the Justice League or their allies. Much to his surprise, the Time-Sphere's controls are locked, meaning Lor has no way to know where or when he's headed to. Once the Time-Sphere reaches its destination, Lor finds himself back on Mars, six months ago, mere moments before Ma'alefa'ak's gene bomb explodes. As Lor finds Superboy attempting to destroy the gene bomb by sinking it into the lava flow, he determines that he's been given one last chance to kill Superboy and doesn't stop for even one second to ponder how or why he's been brought back to this moment specifically. This proves to be a fatal mistake as the Time-Sphere disappears as soon as Lor steps out of the cockpit, distracting him from killing Superboy before Phantom Girl accidentally takes him to the Phantom Zone and leaving him with no time to escape before the kryptonite-laced bomb explodes, killing Lor and etching his shadow on a nearby wall as he's reduced to ash. All according to Metron's design.