This is the implication that a character who dislikes a particular thing is secretly a practitioner of that thing.
This especially comes into play when ethnicity or homosexuality is involved. Such a character is likely to believe in negative stereotypes about his own group (no matter how irrational), and hate himself for it, or live by those stereotypes so they become self-fulfilling prophecies.
In older shows this sometimes comes up with racist characters who are exposed as being light-skinned African-Americans who are 'passing'. Depending on the time frame of the media, the result may be either to show that the character should love himself or, in very old media from before 1940 or so, to show that the character is a sneaky liar who wasn't ethical enough to accept his "natural" place in the order of things.
This sort of implication is "non-falsifiable": If even denial is taken as proof, there's no way to prove innocence. Characters who don't actually fall under this trope, but are accused of it by other characters, may get increasingly angry (or despondent) about no one believing them.
This trope comes in several flavors.
The hater genuinely does not know he is a member of the group he hates.
The hater has clear evidence that he is a member of the hated group but is in denial. He refuses to identify with said group and often comes up with convoluted explanations as to why he isn't actually a member.
The hater privately accepts that he is a member of the hated group but hides it from others.
Alfred J Kwak uses similar parallels. Dolf is a crowsupremacist with a lot of Hitler parallels, and he's secretly half-blackbird.
Hitler was obviously not Aryan, though. Not even close.
There are theories that Heinrich Himmler's Psycho for HireDragon Reinhard Heydrich possessed Jewish ancestry.
Some speculate that rabidly xenophobic half-human Grand Admiral Danetta Pitta, of the Star Wars Expanded Universe, was based in such characterizations of Reinhard.
Hermann Göring's younger brother Albert was said to be a product of their mother's affair with a Jewish friend of the family. Partially subverted in that Hermann loved Albert and kept him from being arrested, even though Albert was a member of the German Resistance who openly and frequently protested the treatment of Jews by the Nazis and who later on passed state secrets to the Czech Resistance.
Anime & Manga
In one chapter of Ai Kora, Maeda attracts the attention of Sajima, a Sadist Teacher who seems to have it out for him because of his "parts love". Turns out Sajima is a parts fetishist himself, but because of this, he was once in a student-teacher love affair that ended in tragedy, and he doesn't want something like that happening to Maeda.
In Bleach, this is the reason why Yumichika and Rangiku have trouble getting their Bankai; they don't like their Zanpakuto because they are just as vain and lazy as their users (though neither of them seem actually aware that they are vain and lazy).
One of the more interesting elements lost in the adaptation of GoLion to the series Voltron is that Prince Sincline is not only the son of a human woman whom his father later disposed of, but that this woman was a citizen of Planet Altea, where his worst enemy lives. His reaction: kill his own grandmother Honerva.
Graydon Creed, the founder of the anti-mutant Friends of Humanity in X-Men, is not himself a mutant — but his parents were Mystique and Sabretooth.
His parents did abandon him.
Played the same in the X-Men animated series, but with a heap more Freudian Excuse.
A closer example would be Larry Trask, son of Sentinel-maker Bolivar Trask. He very nearly succeeded in having his giant robots wipe out all (then-known) mutants, but when his dad's friend Judge Chalmers ripped the power-suppressing amulet off of him, surprise surpise, Larry's a mutant too.
A surprsingly large number of anti-mutant bigots from the X-Men's Rogues Gallery are cyborgs - including Donald Pierce, Akab, Cameron Hodge, Bastion and the Phalanx. So while they're not mutants, they're not exactly normal humans, either.
In Ultimate Spider-Man the biggest mutantphobic person turns out to be a mutant.
The villain Magneto is also an example. He hates Nazis for what they did to him as his family, but as a result became a mutant-supremacist, hating all humans and just becoming a different kind of bigot.
The "homophobes are all secretly gay" idea shows up in a few comics, including Preacher and The Authority.
There is a theory that Rorschach was deeply closeted because of his apparent dislike for homosexuals (and women). See the WMG page for the graphic novel. Somewhat wobbly, since Rorschach dislikes all forms of sexuality.
Red Hulk is implied to be someone who really hates the Hulk. He turns out to be General Ross.
In Empowered, Mind████ takes a peek into (ex-)lover Spooky's memories and instantly grasps that her public persona has been subconsciously patterned after the same vain blonde bimbos she was so traumatized by. Both physically (sans actual Blondeness) and personality.
Said blonde bimbos even sold their souls for "supernatural hotness" (sans superpowers) just like Spooky did, and for the exact same reasons. Spooky discovered this when she tried to use her powers to take revenge — her patron demon didn't allow it because he is forbidden from interfering with other demons' clients.
Film
The main character of Inside a Skinhead is viewing himself as a highly anti-semitic white supremacist, despite being of Jewish origin himself. Of course, he tries to hide his biggest secret but ultimately fails.
In American Beauty, the homophobic neighbor turns out to be a closeted homosexual.
Lampshaded in This is England: one of the far-right extremist characters, Combo, is a racist played by a mixed-race actor... hence his Meaningful Name.
He hates them because they have invaded his homeland, not because they are Romans, though.
Erik/Magneto from X-Men: First Class hates Nazis due to being a survivor of the Holocaust, but ultimately embraces mutant racism which isn't much better.
Isn't it? The film climaxes with what is simultaneously a display of humanity's inherent violence and a reminder that "peace was never an option." If two totally ideologically opposed nations are willing to join forces and obliterate a small band of people who just saved both their asses,it's pretty easy to see why diplomacy might be a bad idea.
In I, Robot, Detective Spooner (Will Smith) displays an intense dislike towards humanoid robots... despite being a cyborg.
Although, he does have an justified Freudian Excuse for that one.
Surrogates features the Prophet, a man leading a group against the eponymous surrogates. It turns out that he himself is a surrogate, controlled by the inventions' creator at that
Literature
Lord Voldemort: racial supremacist for pureblood wizards, hates those with Muggle blood, had a Muggle father himself.
In Deryni Rising, the first book of Katherine Kurtz's Deryni series, Queen Jehana loudly claims her hatred of all Deryni, and later on Morgan describes this very trope when confronting her to obtain her peaceful cooperation during her son Kelson's coronation. It turns out that she is, indeed, a full-blooded member of the magically gifted Deryni race. Thanks to Internalized Categorism, she becomes a Boomerang Bigot and spends several years in penance for the sins of being Deryni.
Seek ye the true reflecting pool? Look to the enemy you despise, not the friend you love.
Hinted at, though never explicitly stated, for one character in Those Who Walk in Darkness. Soledad joined MTac as a means of revenge on the supervillain Bloodlust, who destroyed her hometown. It's mentioned offhandedly that Bloodlust's "power" was his skill at inventing things, which he mostly used to design weapons. Soledad herself designs Abnormal Ammo, including but not limited to phosphorus bullets, poisoned bullets, explosive bullets, and homing bullets, all clearly beyond the skill of any other normal person in the setting.
In the Sword of Truth novel Blood of the Fold the leader of the eponymous organization (which despises all forms of magic), Tobias Brogan, turned out to be one of these. His sister had magic but he was not actually aware of his own abilities. The protagonist Richard Rahl is clearly able to recognize Brogan has the gift, confusing Brogan greatly during a discussion on defeating evil and the insidiousness of said evil, and telling him 'Be careful the shadow you chase is not the one you cast'. Brogan explicitly does not understand what Richard was hinting at.
In the Chrestomanci novel Witch Week, an alternate Earth on which witches are known, feared, and persecuted turns out to also be a world on which nearly every human is secretly a witch.
Shortly after having his new home destroyed, his father killed, and being forced on the run with his mother by the Harkonnen family, Paul points out to his mother that she is Baron Harkonnen's daughter, making them part of the very noble family that they despise.
Essentially directly stated in one of the epigraphic quotations at the beginning of a chapter:
"What do you despise? By this are you truly known."
from the Manual of Muad'dib by the Princess Irulan
In Kate Chopin's short story "Desiree's Baby", the slave-owner Armand rejects his wife Desiree and their newborn son due to the son's obvious African heritage. He takes this to be proof that Desiree is also of mixed heritage, and she eventually gets fed up and goes back home to her parents with her son in tow. While throwing out Desiree's things, Armand eventually comes across letters from his deceased mother that reveal that she was one of his father's former slaves.
Artemis Fowl:The Lost Colony has Leon Abbot, who has an intense hatred of warlocks for relying on magic over brute strength, dispite the fact that he uses magic power he stole from a warlock to brainwash his kinsmen into loyal minions.
Live-Action TV
Stephen Colbert of The Colbert Report considers the gays and their gay agenda to be one of the biggest threats to the USA, and is so deep in the Transparent Closet that a diagram of his brain had a large area labeled 'Repressed Homosexual Urges.'
In the July 28, 2010 episode of The Daily Show, Jason Jones interviewed Scott Lively, who argued that the Nazis persecuted the gays to hide their sexuality:
Scott Lively: The Nazis did persecute homosexuals to distract public attention away from their homosexuality. Jones: So that which you hate the most... you secretly are. (Beat) Lively: I am not gay. Jones: I didn't say you were.
Hazel on Degrassi the Next Generation is rude to the Muslim girl on Culture Day and secretly pretends to be Jamaican, until the Muslim girl's exhibit is vandalized (context: this was only a few months after 9/11) and Hazel comes clean about her Somali heritage.
On Heroes, Angela vaguely hints that Danko, The Hunter of supers, might be a super himself. Whether this is true is left ambiguous.
In an episode of House, Kutner acts pretty hostile towards a group of high school bullies. His co-workers immediately assume he was bullied in high school (as Taub theorizes, being an Indian American and having had his parents murdered in front of him most likely didn't help his popularity). However at the end of the episode, we see Kutner visiting a former classmate and apologizing to him about bullying him. A rare positive example?
More 'you hate what you were' than 'you are what you hate'. Inverted, maybe?
The season two finale of Murdoch Mysteries has a mild example. A visiting Mountie starts upstaging Murdoch in the areas where he usually excels which leads Murdoch to declare "I don't know how anyone could put up with it." As Murdoch walks off his superior says to a third character "Yet somehow I manage." Of course it also later turns out that Murdoch and the Mountie are half-brothers.
Jocelyn Jee Esien's sketch show featured the character of Fiona, a black woman who dislikes black people and fears they will "out" her to her white co-workers, who (she believes) do not know that she's really black.
The image at the top of the page is from Chappelle's Show, which contains an extremely literal example; in the sketch, it is revealed that, in a twist of irony, a blind Klu Klux Klan leader is actually black (and the only reason it has gone unnoticed is due to his robes and his friends hiding his own race from him). This example is added to in the closing narration:
In the past few weeks, Clayton Bigsby has finally accepted that he is a black man. And just three days ago, he filed for divorce from his wife. When asked why, after nineteen years of marriage, he replied, "Because she's a nigger lover".
Extremely southern Blanche from The Golden Girls discovers when attempting to join "The Daughters of the South" (an expy for "Daughters of the Confederacy") that not only is her great-grandmother a Yankee from Buffalo NY, but was nee Feldman.
The Killer Of The Week on an episode of Cold Case turned out to be a Jewish (or at least half-Jewish) member of a neo-Nazi group.
In episode 7x01 of Supernatural, Castiel kills a homophobic preacher who Cas reveals is secretly gay himself.
Music
Pink Floyd's The Wall has the main character become the very thing his father had died fighting against, as noted in the later songs "In The Flesh", "Run Like Hell", and "Waiting For The Worms"...at least within his own mind. This is made even more noticeable in the movie version.
Professional Wrestling
During a segment on WWE Raw, CM Punk taunted John Cena with the fact that he (and by extension, Cena's hometown of Boston, of which Raw was taking place in that night...) was no longer the underdog by consistently being the "top dog" in the WWE, stating that he was no longer the Boston Red Sox, but rather the New York Yankees. Naturally, Cena didn't take too kindly to the comparison and promptly decked Punk after his comments.
Tabletop Games
Quite a lot of ultimate villains in RPGs are like that:
A campaign in the old Marvel RPG had a mutant villain wanting to eradicate all mutants, founding an American NASI party, and of course being mutant himself.
Emperor Karl Prosek in Rifts is rumored to be a magician.
In the Ravenloft setting, Malocchio Aderre seized political control of Invidia and initiated a pogrom against the Vistani. Malocchio's mother, whom he ousted from power, is part Vistani herself.
The general concept behind sanctioned psykers in Warhammer 40,000, who must wield the energies of the Warp to defend Humanity from, among other things, the creatures of said Warp.
The New World Of Darkness sourcebook Second Sight explicitly states that possessors of the two anti-psychic merits listed are latent psychics who have mental blocks preventing them from accessing their powers, and that this in turn makes them virulently skeptical.
Paranoia is generally played with every player character as a "Troubleshooter" whose job is to hunt down various types of traitors, including unregistered mutants. Due to unacknowledged malfunctions in the cloning vats, everyone in the setting is a mutant. Bonus irony if they're also a member of the "Anti-Mutant" secret society, the members of which are completely unaware that there's not a single genetically pure human among them.
Video Games
This trope is given something of a work-out in Fate Stay Night, especially in the "Unlimited Blade Works" route: Archer is quite vocally disapproving of the idealism and stubbornness that seems to plague most of his 'allies' (especially Shirou), and yet it is repeatedly pointed out by several characters and scenes that he is, in many ways, just as bad when it comes to suffering from Chronic Hero Syndrome. Just to make things weirder, this is a LITERAL example in regards to Shirou, considering that they are the same person.
In Grand Theft Auto IV, a politician is having an affair with Bernie Crane, while campaigning against same-sex marriage in order to appease his right-wing voter base.
Adrian from X-Men: Destiny is a Purifier-in-training and despises mutants. Turns out he is one, though he had no way of knowing until the events of the game.
Bertrand from inFamous 2 considers Conduits to be demons and ultimately wants them to be exterminated, but is secretly a Conduit himself.
Although Cole points out that he most likely is jealous of the fact that whilst others became shiny supermen, he got to be a big bug. So maybe instead of "you are what you hate," he falls more under "you hate that others like you possess awesome powers yet yours suck."
In Hatoful Boyfriend, Sakuya, the proud heir of a pureblood fantail noble family, treats every non-pureblood bird like trash, including even his half-brother Yuuya who he calls a "half-breed mongrel". However, he learns on the Bad Boys Love route that he's actually not the true heir of the Le Bel family and is Yuuya's full brother, which means that he's the very same "mongrel" that he constantly scorned Yuuya for being.
Western Animation
In one episode of Spongebob Squarepants, Squidward claims he hates Krabby Patties, but after just having a tiny bite, he tries harder and harder to secretly get a Krabby Patty. He is finally caught in the Patty Vault.
For clarification he hated them before he ate them because he's Squidward and he's a grump but after he ate one, he loved it but lied to everyone, including Spongebob who later finds Squidward eating thousands of Krabby Patties. Which go straight to his thighs. And then he blows up. (Run-on sentences without context are fun!)
And since he has convinced the brewery to fire illegal immigrants, well...
King of the Hill has an interesting case: Hank Hill, proud Texan that he is, is initially horrified to find out he was actually born in *gasp* NEW YORK!
Played with on South Park. Cartman hates "Gingers" (People with red hair, freckles, and pale skin) and insists they have no soul. As revenge Stan, Kenny, and Kyle draw freckles on him and dye his hair red in the middle of the night. He then hangs out with the gingers and whips them into a genocidal frenzy against everyone else. At a massive rally, they're about to kill everyone who isn't a ginger (starting with the "Daywalker," Kyle) only to have Stan, Kyle, and Kenny reveal Cartman's not a ginger. Then he just goes back to ripping on gingers.
And then in 201 it turns out Cartman's father was also Scott Tenorman's father, making Cartman half-ginger.
Mr Garrison is homophobic in the early seasons, and is in denial about his sexuality throughout seasons 1-3 until he admits to himself that he is gay in the fourth season. When his sex change results in Mister Slave breaking up with him, he goes back to being hateful to homosexual men, and when it turns out Mister Slave is going to marry Big Gay Al, Garrison becomes an angry opponent of gay marriage. Then there's a mini-arc where Mrs. Garrison thinks it's "wrong" to be with another woman, but enjoys it and claims to then be a lesbian... And then there's a reverse sex change and Garrison becomes a man again, and almost immediately uses a homosexual slur. There's a quote from one of the creators that goes something along the lines of, "Garrison just hates whatever he happens to be."
Uncle Ruckus from The Boondocks. He's the darkest guy in the series and he hates black people with a passion. He does his best to distance himself from being black, holding on to whatever European heritages he believes he has ( though a genetic test in one episode reveals he's 102% African, with a 2% margin of error) and claims to have a condition called "re-vitiligo", the "opposite of what Michael Jackson had", which supposedly causes him to get darker.
When Springfield tried to pass a law deporting all immigrants in The Simpsons, Moe was one of its most vocal supporters. He viciously blames them for everything that ever happened in town, including bear attacks, and rants about things that piss him off about them like not learning the local language. He was later spotted nervously taking the citizenship exam wearing a very thin disguise.
In an episode of Futurama where Bender and Amy had a robosexual relationship, Bender at one point was sent to a retreat where Preacherbot urged sinners to wrestle with human mannequins in order to symbolically beat out their sinful impulses. Naturally, this entailed the robots making out with the mannequins. Preacherbot was clearly aroused.
In Justice League, General Eiling who deeply despises superheroes and metahumans, when Cadmus was disbaned, decides to use a superhuman serum and turn himself into "The General" and fight the Justice League, so far only face the League's non-metahuman members, and the crowd calls him out on his actions.
In Recess, Spinelli despises "The Ashleys" (a group of Alpha Bitch-esque girls all named Ashley) yet becomes very defensive when it's pointed out that her own first name is Ashley.
Actually it doesn't appear that she hated her first name, she just hated the fact that it grouped her with those Ashleys as she was clearly anything butGirly Girl.
Also in Poland, 'anti-fascist activists' were calling to block (and ultimately forcefully blocked) the legal march commemorating Independence Day because they considered it 'fascist'. Illegal suppression of freedom of speech and assembly is exactly what Nazis did before they gained legal power.
Adolf Hitler himself has been accused of having Jewish and even African ancestry based on DNA evidence.
There was also Emil Maurice, founder of the SS, who was found to have Jewish ancestry. Hitler granted him the title of "honorary Aryan."
Leo Felton who planned to blow up Black memorials in America is the son of an African American father. He came up with convoluted theories to argue that he was white rather than black, most notably arguing that race was more spiritual than biological.
Certain fandoms tend to receive flak, such as Furry Fandom, yet a sizable number of people who tend to criticize certain fandoms are, to some extent, part of them.
