Wang Sau-leyan in Chung Kuo, ugly, fat and clumsy, was treated as a poor sequel to his brothers while he grew up. This is not presented as an excuse for his behavior, but it helps explain it.
Marco from Animorphs is a snarky survivalist early on. While Tobias exalts about how with great power Comes Great Responsibility, Marco snaps back that Tobias can't even go a day without getting his head flushed down a toilet. Once Tobias is stuck as a hawk, Marco's barbs begin to verge on actual cruelty. Later, we find out that Marco's mother supposedly drowned, and his father suffered a nervous breakdown; Marco is terrified of dying because he's afraid of what will happen to his father if he does. He fully admits to being a Sad Clown and that he makes fun of Tobias because what happened to Tobias scares him. He gets better pretty quickly though, once he finds out that his mother is alive, she's just Visser One's host.
Visser Three, of all people, gets one in The Hork-Bajir Chronicles. He lived blind and deaf in the Yeerk Pool for a long time, and when he finally got fifteen minutes in a host, he loved it so much that he swore he'd do anything to get into a host. And then his host's back was broken and he was left there for hours on end, giving him his first real exposure to pain. Finally, the reason he specifically wanted an Andalite host was that his first experience with Andalites and morphing was an Andalite in morph trying to kill him. This makes his fate at the end of the series all the more horrifying: spending the rest of his life without a host.
Subverted in Visser with Visser One. It looks like the author is going to reveal a sympathetic backstory, but she never does, and you can almost feel her laughing at you for thinking that Visser One might be sympathetic.
Isaac Asimov: The Mule is driven to conquer the galaxy because of a childhood of ostracism and abuse due to his physically deformed stature; he claims in his internal monologue that it is now "his turn." Appropriately, he is stopped by a master psychologist administering instant therapy with a bit of mind control thrown in for good measure. He spends the rest of his life happy — and out of the way.
Subverted in Children of the Mind: In a backwards attempt to explain why she is so contrary, Quara reveals to Wang-mu that she was sexually abused at a young age by Quim, her soon-to-be sainted brother. When Wang-mu immediately believes her, she reveals it wasn't true, but points out the hypocrisy of people who would more easily believe the worst in a saint of a man like her brother than believe that some people are inherently, for no real reason, jerks.
Subverted in one of the Dancing Gods books, wherein a) the character discussing his tragic early life is on the side of good, and b) it transpires that this tale of a sad past is complete and utter nonsense designed to throw the villain off his game. It works.
Averted in Dostoevsky's novel Notes from Underground to the point of being An Aesop. Dostoevsky was concerned with the far-reaching consequences of certain ideas being batted around in his day - essentially, that despite humankind appearing to be fundamentally irrational and uncontrollable, using psychology and whatnot they'd one day be able to figure out exactly what makes people act the way they do, and could correct anti-social behavior easy as solving a math problem. (And then they could fix all their woes and achieve a socialist utopia, hooray). So he wrote a book featuring a maladjusted hero who's a miserable prick for no reason and will no doubt continue to be a miserable prick no matter what happens to him. Needless to say, it was not popular with Soviet critics.
Nancy Farmer's The House of the Scorpion: El Patron's ruthlessness arises mainly from the fact that he lived a dirt poor childhood, and was the only surviving child of a large family. The man was forced to live by his wits.
In Stella Gibbons's Cold Comfort Farm, having seen "something nastyin the woodshed" isn't just Aunt Ada's excuse for being a domestic tyrant who never leaves her room, it's also how she does the tyrannizing: anytime anyone tries to leave, or do anything else she disapproves of, it "brings on her trouble". Flora finds this suspiciously convenient.
Hannibal Lecter lost much of his mystique when explanations for his actions were presented in Hannibal and Hannibal Rising during his jarring Badass Decay into a misunderstood Anti-Hero.
The author was all but forced to writeHannibal Rising, having been told that if he didn't provide a backstory for Dr. Lecter, some other writer would.
Jame Gumb and Francis Dolarhyde are given very detailed backstories in the novels, which works well to humanize them. Gumb was born to an alcoholic prostitute and lived in foster homes until moving in with his abusive Grandparents at the age of 10. Dolarhyde was born with a severe disfigurement to his face and was abused by his Grandmother, after being ditched by his stepfather's family which had the same structure as the families he killed. There is only one reference to Gumb's Freudian Excuse is given in the movie, however, which is "Billy was not born a criminal, but made one by years of systematic abuse." It works rather effectively.
Between the level of detail that goes into the other serial killers' backstories, the recurring emphasis on psychology (as unreliable as it can be), and Lecter being, well... Lecter, it's likely that Lecter's seemingly inherent evil was meant as the exception, not the rule.
Gaston Leroux's The Phantom of the Opera gives an excuse for Erik's cold bloodedness: humanity hates him because of his deformity, so he hates humanity. The Phantom adaptation gives more of a backstory to this: in addition to the deformity, his mother shows him no love and keeps him shut inside where he can't fully use his genius. Still a creepy guy for a protagonist.
There's a similar version in the 1990 TV miniseries. While the Phantom's murderous behavior is not condoned or excused, when we get his backstory, his mother is depicted as loving and adoring him despite his deformity, and it is appears that his passion for Christine is based on the resemblance between the two. Which is a whole other Freudian Excuse.
"If you really want to hear about it, the first thing you'll probably want to know is where I was born and what my lousy childhood was like, and how my parents were occupied and all before they had me, and all that David Copperfield kind of crap, but I don't feel like going into it, if you want to know the truth."
And then played straight, as you realise that Caulfield's deceased younger brother is a large part of the reason he's so unhinged.
Deconstructed in Lolita- Humbert's reason for being a pedophile is very Freudian (at age 16 he was interrupted having sex with his childhood sweetheart who died shortly afterward) and he thinks about it in these terms. However, the author's point was that this is a poor excuse for his terrible actions.
The mostly sane (he hears voices in his head, but that's alright, one of them is his psychiatrist!) protagonist of Eric Nylund's A Game of Universe has a more subtle Freudian Excuse for his background. His childhood (born on a hellhole of a planet, dad killed his mom when he was born, dad whored out his brother to miners (a fate he only avoided by being too young at the time), then accidentally killed his brother while his brother was trying to rape him) doesn't mess him up that badly, it's only when this background leads him to panic over a misunderstanding and murder his mentor does he really start to lose it. (He spends the next few months hiding in a sewer, and then the next few years in a school based on Klingon Promotions.)
A kind of subversion, based on going into more details. In Artemis Fowl and the Lost Colony we are introduced to Billy Kong (previously called Jonah Lee), and told that his teenage brother was killed when he was quite young. Later, we learn that when Jonah was young, his brother claimed that he was part of a secret group that fought child-eating demons, in an attempt to keep Jonah off the Miami streets while their mother was working, due to trouble his brother had been having with a gang at the time. When his brother was murdered, Jonah was convinced that demons did it, and he and his mother moved to Taiwan (where she was from) shortly after. Jonah is said to have later decided his brother had deceived him, causing him to become inherently distrustful and making it easier to hurt people, which combined with the environment he grew up in, turned him into a violent criminal. Shortly before the book begins, he is hired to help capture a fairy demon, causing Kong to start wondering if his brother had been honest after all. When Holly is captured while trying to save the captive demon and is being interrogated, she uses her knowledge of Kong's past to try and psych him out, and unknowingly feeds into his delusions by "confirming" the abilities that Billy's brother said demons had. This leads to Kong having a rather tragic nervous breakdown, and starts an obsession with destroying all demons, and killing anyone who gets in his way.
Inverted with James T. Kirk, whose tendency to Take a Third Option is explained in various Star Trek novels as being a result of surviving the mass executions on Tarsus IV (from the TOS episode "The Conscience of the King") as a boy. It also probably explains why he doesn't believe in the The Kobayashi Maru and the No-Win Scenario.
Tigerstar: His father abandoned him at a young age to be come a kittypet, causing his irrational hatred towards kittypets, and he was mentored by an incredibly aggressive warrior whose personality traits seemed to rub off on him. Apparently, father issues, an aggressive personality, racism, and ambition combine to create the feline version of Hitler.
Scourge: He was constantly teased and excluded by his brother and sister until he eventually ran away from home, where he was attacked and almost killed by Tigerstar. He spent the rest of his life trying to prove that he was strong, and to get revenge on Tigerstar, which eventually lead him to being a mass-murdering psychopathic dictator.
Hawkfrost: Not mentioned often, but Hawkfrost was essentially an orphan and had to grow up living in his father's shadow until he eventually decided to follow in his footsteps. Also, his brother died, that might have something to do some of it... kinda...
Brokenstar: He had a horrible foster mother in his kithood, who hated him and always tried to exclude him, making him the Un Favorite. Due to this, he saw aggressiveness as the only way to prove himself, and eventually killed Raggedstar, his real father, to show that he could become a leader, and prove his greatness. This lead him to commit all sorts of atrocities, so that he could make ShadowClan the strongest Clan of them all.
Ashfur: Started out as an adorable, boisterous young apprentice, until his mom was killed indiscriminately by Tigerstar. Fell in love with Squirrelflight, only for her to pass him over in favor of Brambleclaw. Then he was forced to mentor their "son", whose very presence was a constant reminder of the mate that he lost. He eventually went insane and went on a Roaring Rampage of Revenge, attempting to kill Squirrelflight's "kits" to make her feel the same emotional pain that he felt when she rejected him.
Mapleshade: Fell in love with a RiverClan warrior, but when she tried to bring her kits across the river into RiverClan territory (since her own Clan had driven her out), the kits drowned. Eventually, the tom she was in love with found another mate and had kits with her. She hated Crookedstar because he was her former mate's great-grandson.
And Sol has been given a backstory as well: His mother, Cinders, didn't really care for her kits - she hadn't even bothered to name them - and complained all the time. His father was never around. The only good part in his life was that she told them stories of "sky warriors". She eventually abandoned them at different Twoleg nests. Sol felt that if he could have been a "sky warrior", she might have been proud of him and stayed around. Then he discovered SkyClan, but after trying to train with them, they felt he didn't respect the warrior code, so they wouldn't make him a warrior. This resulted in his trying to get revenge on all the Clans, not just SkyClan.
Snape from Harry Potter was revealed to have had an abusive father and poor home life in Order of the Phoenix. This in turn led to him gaining a mutual and deep hatred with James Potter, both having pushed one another's buttons.
Oh, it's worse than that: Snape's only friend and love interest growing up was Lily Evans, but his poor lifestyle choices (hanging with would-be-Death Eaters and supporting their racist cause, even though that cause is racist against people like Lily) ended up pushing her away from him. Who'd she end up marrying? James Potter. Harry is not only James' son, but the son of James and the woman Snape loved, something Snape is always reminded of when looking at Harry (who has his father's face, but his mother's eyes.) To Snape's credit, Harry being Lily's son is also the reason he protects him, despite his bullying of him. Furthermore, he never blamed James for Lily, but blamed himself. This probably meant that even if Lily wasn't in the picture, Snape would still be The Resenter to James.
Invoked and consciously averted with Voldemort. His upbringing as an orphan was far from ideal, but others (most notably Harry himself) were brought up in worse conditions without using it as an excuse to become Wizard Hitler. It's also implied that Voldemort is unable to feel love and compassion because he was conceived through Merope Gaunt using a Love Potion on Tom Riddle, Sr.
Harry's aunt Petunia hates, hates wizards in general and her witch sister Lily in particular. Then we see when Lily got her acceptance letter to Hogwarts, Petunia got a letter too, telling her she wasn't a witch...
Capricorn in Inkheart, though it certainly isn't an attempt to justify his cruel actions; we just learn from Fenoglio that Capricorn's father was extremely abusive, and beat him for offenses such as showing pity. It is implied that the abuse was at least partially what made him cold and heartless.
In the short story collection The Further Adventures of the Joker, the eponymous Joker gets a story devoted to a snapshot of his childhood with an abusive father (SMILE, I SAID!) as the centerpiece. That, and killing small animals and collecting the bones to make grotesque sculptures. Perhaps most notably, we get some insight into how his father got to where he is. Big surprise — it involves his father.
Jane Austen's Mansfield Park contains a Take That at this trope: Edmund excuses every red flag in Mary Crawford's behavior as the result of faulty upbringing or the influence of bad friends. He finally has to admit he's been Loving a Shadow and the perfect woman he thought was spoiled by a crappy childhood in her uncle's house is a Rich Bitch who was hoping his ill older brother would die so Edmund would become the heir of the family and be rich enough for her to consider marrying.
The title character of the Wally McDoogle series writes a new superhero story in every book in between the action. Every one introduces the Villain of the Week with speculation as to what might have caused him to turn evil.
Herod Sayle of Stormbreaker (renamed Darrius Sayle in The Film of the Book) came from a poor Lebanese background and was sent to a British boarding school after saving a wealthy English tourist couple (in the film, he was an American who lived in a trailer until his mother won the lottery), where he was bullied due to his background by several other children, many of whom became influential figures in British government (including the Prime Minister). His reaction to this is to invest in a multi-million dollar advanced computer system which he would donate to the British school system, which secretly contains biological weapons which, when simultaneously activated, will kill millions of children, and probably thousands of other innocent people. Lampshaded in the movie.
Alex Rider: Alright so you were bullied; lots of kids are bullied! It doesn't turn them into mass-murdering psychopaths!
Same with Desmond McCain, who was bullied for being black and criticized in the newspapers. Still doesn't justify his evil charity and his love of killing.
General Alexei Sarov, from the third book. His son was killed at war, and then he lost the country that he lived for. That still doesn't come close to excusing him for his plan to cause a massive nuclear explosion.
In Scorpia Rising we have Julius Grief. He is a fifteen year old who gets pleasure from other people's pain, seems quite fond of murdering people, and is consumed by his hatred of Alex. However, considering he was created and raised so he would be evil, with no purpose other than helping Doctor Grief take over the world, and it is stated that he and the other clones got the cane if they shot a gun the wrong way, resulting in him being completely insane, it's hard not to feel a little sorry for him.
Not really. He never experienced any sort of emotional pain or trauma in his childhood, and never spoke badly of his father. In fact, the fact that his own psychologist instinctively dislikes him seems to be a subtle hint that readers should not pity him.
Dr. No, in the novel of the same name, got where he is in large part due to his father's rejection of him. His beginnings in the crime world — violence, destruction, and a general lack of empathy — were largely a reaction to his father's treatment of him and a manifestation of his rejection of authority in general. Curiously, by the events of the story, he is plainly aware of this fact and doesn't hesitate to put it in those very words.
In Watership Down, General Woundwort's violent and un-rabbitlike behavior stem from his traumatic kittenhood, in which his father was shot, his siblings scattered, and his wounded mother killed and eaten by a weasel right in front of him. Adopted and nurtured by a kindly human, who'd nevertheless failed to keep his cat from menacing the young rabbit, Woundwort never learned to interact civilly with other rabbits, and his lapine psyche became warped, his natural flight-instincts supplanted by aggression.
Truth in Television, as captive-reared wild animals tend to develop behavioral problems and socialize poorly with their own species.
In The Silmarillion, some of Fëanor's rash actions can probably be attributed to the fact that, in what was virtually paradise, his mother was the first person ever to die, that his father (however loving) remarried (which was completely unheard of and never happened again), had other children, and then was the first person to be killed in Valinor. Now, in the published Silmarillion, this is not belatedly revealed to excuse Fëanor's actions; in fact, it's not explicitly held up as an excuse at all. However, it is a relatively late addition to the Quenta Silmarillion: in earlier versions, Fëanor's just someone who obsesses over his jewels and hates his brother because of Morgoth's lies; later, he's also to be pitied, a bit.
In Violet Eyes, the reason for Dr. Frankenstein's cruelty is that during his childhood, he was jealous of his brother, who was more talented than he was.
This one depends upon your point of view. In "The Icemark Chronicles" Medea had a bad childhood because her parents didn't give her the attention that her sibling had. However there is a debate among fans as to whether this was her parents fault or her own.
Crenshinibon from the Forgotten Realms was originally an extremely powerful and dangerous but nonsentient artifact. At one point it fell into the hands of a sultan who overestimated its power and relied entirely on the crystal towers it generated to protect his land from invasion. He realized too late that the more towers that are created they weaker they are, and his lands were overrun. At the moment of his death, his tormented spirit merged with the Crystal Shard, and at last Crenshinibon was complete. The insatiable desire for power and control that Crenshinibon forces upon its wielders is the twisted reflection of a sad man's regrets of failing to protect his people.
The mystery villain of Janet Evanovich's Smokin' Seventeen engages in his killing spree because Stephanie's it's-complicated Joe stole his girlfriend back when they were all in high school together, so now he intends to steal Joe's girlfriend. With murder. Somehow.
In The Pale King, The unnamed narrator of Chapter 23 has issues with regards to his self-worth. He remembers a presentation he did on The Iliad in the eleventh grade, and he freely associates it with his family. He likens his family to Achilles, in that his seemingly perfect brother is Achilles's shield, while he is the heel. He even develops a fixation on people's feet.
In Death series: Played straight and averted across the series. Some of the murderers have this, and some of them were always evil. Either way, Eve and Roarke do not consider the Freudian Excuse acceptable, considering the Abusive Parents they had.
Max Barry's Machine Man has the excellent example of Lola, whose father deliberately self-maimed himself in a series of industrial accidents to collect insurance and pay for Lola's Heart Trauma replacement. As a result, Lola as an adult finds men who've lost body parts irresistible, and works in prosthetics.
Sisterhood Series by Fern Michaels: Averted for the most part across the series. Practically none of the bad guys have a single excuse for their behaviour. With that said, Senator Webster from the book Payback and John Chai from Vendetta may be exceptions. The Senator had good parents, but he distanced himself from them and disowned them because he was ashamed of them and the fact that they were so low-class! John Chai is the son of a diplomat and an ambassador, and he may have gotten feelings of entitlement and being untouchable from being born in all that power, wealth and position.
The narrator/protagonist of Letters Back to Ancient China (a time travelling mandarin from medieval China) compliments a western woman on her breasts. She rationalized his odd behavior by concluding that he wasn't breastfed enough.
Many Inheritance Cycle villains have these. Sloan is such a jerk because his wife died, and Galbatorix was partially motivated by the death of his dragon.
On the other hand, Lisbeth has very little sympathy or fellow feeling for Harriet; but that probably says more about Lisbeth than anything else.
In Richard Condon's Manchurian Candidate Raymond's mother is a seething pool of Freudian motives. She had an incestuous relationship with her father. Hated her mother as a sexual rival and complained that she could not understand how he could lie down with such an ugly woman (people said that as an adult she was nearly a twin for her mother). When her father died, her older brother claimed leadership of the family and she swore that she would follow him into any profession he chose to outdo him, and crush him. He chose politics.
In the Belisarius Series, Empress Theodora's obsession with power (both the trappings and reality thereof), gut level distrust of anyone with a working penisnote (she is honestly devoted to her husband Justinian, but trusting him fully is another matter), and overall mean streak is quite fully explained by her being sold to a pimp at the age of twelve... by a father who had started raping her when she was nine.
This is part of the basis for A Christmas Carol. Scrooge is a Jerk with a Heart of Jerk at the story's beginning, but the Ghost of Christmas Past takes him back to see the various Freudian Excuses that made him that way. His mother died at a young age, leading his father to abandon him at boarding school and never return home, even at Christmas, which taught him not to empathize with his fellow man. When he became a workaholic obsessed with getting ahead, his fiance realized he cared more about money than her and left him. He hates Fred, his good-natured nephew and only living relative because his beloved sister died in childbirth. And all of these events happened over Christmas, making him despise the holiday. None of these excuses really serve to justify Scrooge's cruelty or selfishness, but do highlight his chance at redemption.
In the off-Broadway Radio City Music Hall Production, Scrooge had a much different Freudian Excuse. His father was sent to debtor's prison, and the only advice he could give his son was to remain thrifty at all costs and avoid a similar fate. His mother died shortly afterwards trying to raise him and his brother himself, but he took the advice to heart, eventually taking it too far, again caring more about money than anything else.
Trapped on Draconica: Zarracka was spoiled by her mother and then banished for seeking attention by summoning an emperor ghoul in the capital. The only reason she started working for Gothon is because she was living in a city that he conquered.
In Galaxy of Fear, the Children are cannibals. This is because their stranded parents, starving, unable to stand the sound of their children crying from hunger, started to feed the dead to them. Malnourished and uneducated - the last of the parents died when the oldest of the Children was seven - the Children remember this as something joyful, as the ultimate act of love, even though it was clear that their parents were absolutely horrified. Hearing about this makes Zak Arranda a lot more sympathetic towards them.
Yandere Penny the monster bringer's father was a pedophile and her mother was dead. Penny was also the The Unfavourite out of her two sisters, and felt bitter jealousy towards them. This was shortly followed by her father being imprisoned. in later books, Penny also has her legs broken, which Caine describes in FEAR as what really pushed her off the precipice of insanity and evil
Orc (who is a villain only in the first book before becoming more sympathetic), was abused by his father (Michael Grant seems to love this trope) to the point where a electric drill went through his arm. And as of the end of the first book, is a stone-monster and alcoholic
Even Smug Snake Zil Sperry seems to have one, although it seems a little less tragic. Zil was simply the "unfavourite" in comparison to his little brother, which kick started his jealous and bitter traits.
Bug had a abusive step father who beat him, and a sick, alcoholic mother. His brother also got high a lot on class A drugs and liked to torment and bully him. The reason he was sent to Coates was apparently for "his own safety".
The only case in which this trope in averted is in sadistic, reprehensibly violent Drake Merwin, whose only motivation behind his heinous, psychopathic acts is "YOLO, bitch!"
"I had a hard life. Hard for my parents, I mean. It wasn't that bad for me." - Drake Merwin.
Skulduggery Pleasant has Argeddion, a Well-Intentioned Extremist who was actually a pretty nice guy. Who was wrongly put in a coma, then beaten up his own alternate universe self, before having to watch his beloved die right in front of him, and see his ideologies, everything he believed in, collapse in front of his eyes. Then he gets pissed off and goes into full villain mode.
Percy Jackson and the Olympians has Luke Castellan, who for the first four books is just portrayed as a douche and a Manipulative Bastard, before the fifth and final book tells the pretty sad tale of his past. Ok, so he doesn't know his father, who left him with a insane, abusive mother who threatened him and never let him leave the house. Then, at just nine years old, he's forced to run away and live on the streets, in dangerous, cold New York. After that, he finally meets his father, who essentially tells him he wants nothing to do with him and won't help him. (Justified in that it's dangerous for the gods to intervene with their children, but Luke didn't know that). Shortly afterwards, one of his only friends is turned into a freakin' TREE. Then the gods give him a quest "just to keep him busy", which involves him getting permanently disfigured. At this point he's naturally annoyed at the gods and joins the Titans. And then, once one of his few real friends comes back to life, she tries to kill him. Damn. And when he finally decides to do a Heel-Face Turn to save one of his friends (and consequently the world), he has to die for it. And while he's lying on the ground, the friend he just saved tells him she never loved him. Ouch.
Tywin Lannister's father was a good man who had his kind nature frequently taken advantage of and who was mocked by even his own bannermen for his perceived weakness. After his father's kindness nearly brought their house to ruin, it was up to Tywin to restore the glory of the Lannister House, no matter how ruthlessly he had to act in order to do so. Tywin also served as Hand to the Mad King, Aerys Targaryen, and had his successful efforts to stabilize the realm rewarded by Aerys treating him as nothing more than a servant whose daughter was unfit to marry into Aerys's family. The best part of him, inspired by his love for his wife, Joanna, is said to have died when she did.
Cersei Lannister has spent her entire life horrified that a prophecy about her future would come to pass. She was told, at a young age, that all of her children would die before she would and that she would be killed by her younger brother. This explains both her extreme overprotectiveness of her children and her absolute loathing of Tyrion.
Sandor Clegane was mutilated at a young age by his psychopathic, older brother, Gregor, who burned off half of Sandor's face for playing with one of Gregor's discarded toys. Sandor's father and little sister are also implied to have been murdered by Gregor, and Sandor, who grew up witnessing his brother be rewarded for his atrocities with a knighthood, has become convinced that all knights are monsters who kill for the pleasure of it. For these reasons Sandor believes that neither gods nor nobility exist in the world and that only the strong are able to do as they wish, so he embraces his Blood Knight tendencies.
Gregor has a bit of one himself. His freakish size is implied to be due to a brain tumor that both gives him frequent crippling headaches and drives him into a constant rage. Combine that with the hints that both him and Sandor were raised to kill the same way a dog would be raised to hunt, and it's understandable how they ended up the way they did.
Petyr "Littlefinger" Baelish originally came from a small house but was fostered at House Tully for much of his childhood. While there, he was frequently mocked for his family's poor standing. Petyr fell in love with Catelyn Tully, but Catelyn only loved Petyr like a brother. When Petyr, urged on by stories of knights and adventure, attempted to duel for her hand against her then fiancée, Petyr was left scarred but alive at Catelyn's urging. While delusional and recovering from his duel, Petyr was taken advantage of sexually by Lysa Tully, who became pregnant with his child but was forced to abort it at her father's insistence. In retribution for his duel, Petyr was sent back to his poor house and Catelyn cut off all contact with him. These events helped turn Petyr from a young boy who loved stories of knighthood and romance, into a Machiavellian schemer who believes political plots are the only way to gain power.
Ever since Viserys Targaryen was a boy, he had the hopes of his entire destroyed house resting on his shoulders. The stress of his task, along with being so poor that he had to pawn everything of value he had, even his mother's crown, and the years he spent being ridiculed as "The Beggar King," eventually caused his descent into madness.
The Star Trek Novel Verse essentially uses this trope for whole societies. Few cultures in Star Trek are "evil" by nature, but the traumas of their development often forge them into unpleasant antagonistic societies (an idea that may have started in Star Trek: Deep Space Nine as the Founders' Start of Darkness came from their desire to impose order and safety in a galaxy that persecuted them). Fear and hurt on a civilization-wide level, leading to a culture lashing out in aggression and conflict, is a staple theme, particularly in portrayals of the Cardassians and Klingons. In fact, whole ongoing sagas explore these two societies coming to terms with themselves and their deep-stated fears. The Tholians, Romulans and even Borg have also had their "Freudian excuses" explored. Greatly simplified, for Klingons it's the Hur'q invasion, for Cardassians the climatic catastrophe that nearly starved them, for Tholians oppression by the Shedai, for Romulans the difficulties of the exodus from Vulcan. As for the Borg, see Star Trek: Destiny.
In the Temeraire series, most Europeans regard dragons in general as savage bloodthirsty creatures barely kept in check by their handlers. The eighth book Blood of Tyrants reveal that Russian dragons (especially the heavyweight ones) live down the these expectations... then we see that they spend their formative years pinioned, half-starved at best, and largely treated with the sort of abuse that would make most humans psychotic.