Generational Trauma

Generational Trauma is a psychological phenomenon where older generations pass on their horrors, traumas, and angsts to the new blood. Sometimes the older groups aren't even aware of it or can't understand that there's something wrong, perhaps owing to the stigma of therapy and lack of awareness. Read more here.

In fiction, generational trauma is shown to play out over a relatively short time period. The exception may be in intergenerational novels, where you see hundreds of years pass at a time. Usually the person that passed on the trauma has to confront their demons, and the consequences of their actions.

You are more likely to see generational trauma in non-Western works, but it may crop up in Western stories as well that talk about Abusive Parents (perhaps as a Freudian Excuse for the Troubled Abuser) or PTSD. Western works are more likely to shorten the timespan, so that the viewers get a sense of completion and closure.

Compare Sins of Our Fathers, which sometimes stems from the generationally traumatised seeking to resolve their issues by punishing the descendants of the traumatisers. Alternatively, the trauma could stem from the descendants of the Sinning Father getting shamed and stigmatised or outright physically harmed for said ancestor's legacy.

Examples of Generational Trauma include:

Anime and Manga

My Hero Academia regularly has examples of tragic villains that result from this. You had normal kids that were abused by parents with superpowers, and then lash out when they grow up and have children that gain powers. Tomura is a classic example of this, being abused by his family for the crime of having a Quirk. There seems to be no end to the cycle, except with compassion and a clear understanding to stop the pain.
Yona of the Dawn has this play out gradually over time, in regards to both Yona and the main antagonist Su-won. Yona is raised as a naive and spoiled princess who loves her cousin Su-won and thinks that she can persuade her father to let them marry. Then she witnesses Su-won assassinate the king on her birthday, and Su-won proceeds to order her killed as well. She finds out over the course of the series, while on the run with her bodyguard Hak, that Su-won is acting out of the belief that her father killed his father. Hak himself can't believe it, as Yona's father was a pacifist to the point of being an Extreme Doormat and a terrible king owing to his inability to be stern or violent when necessary. Su-won himself is affected by his father's legacy, as well as the consequences of his actions.

Comic Books

The comic book Maus discusses this in Part Two, as Art goes to see a therapist after his father dies while pondering that his wife Françoise Mouly is pregnant with their first kid and that the Maus comic is not yet finished. He feels guilty that he had a good life in the American suburbs, with enough food to eat, while his parents endured concentration camps and his older brother Richieu died via cyanide pills. Yet his childhood and adulthood were filled with his father's embarrassing miserly ways and his mother's depression which eventually led to her death by suicide. Art even mentions to Françoise that he thought all parents screamed in their sleep. His therapist Pavel, also a Holocaust survivor, talks to Art through his mixed feelings about finishing the book, and what it means to survive. Nadja Spiegelman would later write her set of memoirs explaining that her parents were decent people, but her maternal grandfather took offense at Nadja discussing French collaborators.
The Sandman has a few instances.
- Dream is a butthead, sometimes. He's arrogant, a stickler for the rules, and stubborn. He also has his own traumas that come with being the King of Dreams: having his sibling Desire charm away his paramour merely because Desire thought it was funny, witnessing another paramour throw herself over a cliff when their night of sex caused her village to be destroyed, and having an older sibling walk out on the others. These naturally aren't a good combo for being a father. Dream treats Orpheus cruelly when the latter breaks the rules of the universe to try and resurrect his wife, leaving Orpheus's severed immortal head on a beach where it washes up following the Maenads' attack. By the time Orpheus is recovered and exiled to a Greek island, he just wants to die. Daniel, Dream's designated heir, vows to not continue the cycle of arbitrary abuse.
- Rose Walker, her mother and her brother Jed (offscreen as what he suffers onscreen is much worse) grapple with the fact that Unity Kincaid was raped while suffering sleeping sickness and conceived their mother, who was adopted out to an unknown family. Mrs. Walker takes it well after the initial shock, considering she meets her biological mother when Unity is a dying old lady and tends to her during her last few days. The rape in question made Rose a vortex, an Apocalypse Maiden that Dream has to kill to save the universe. While Unity saves her in the Dreaming, by taking Rose's place and becoming the Vortex as was originally intended, Rose becomes depressed and aloof for several years unable to comprehend that her grandmother gave her life for a granddaughter she knew for less than a year.

Film

Encanto puts this on full display for most of the movie. Abuela Alma witnessed bandits murdering her husband who attempted to protect her and their triplets, along with a group of refugees. When the miracle happened-- an ever-burning candle caused the mountains to rise and dispel the bandits while creating a safe haven for the survivors, and giving magic to Abuela's children-- Abuela became convinced that the best way to respect the miracle was to make her children useful. Unknowingly, her demand for perfectionism and rigidity causes her to alienate her powerless granddaughter Mirabel who tearfully pinpoints at her Rage Breaking Point that she will never be good enough for Abuela. That's not even going into how she inadvertently turned her son Bruno into the town's pariah who opts to hide in la Casita walls to mend the cracks and protect Mirabel from one of his prophecies, has driven her other granddaughter Luisa to a near-breakdown with how Luisa feels she needs to literally carry the house's burdens on her back, and treats Isabela as the golden child who must never get her hands dirty despite an affinity for plants. It takes la Casita crumbling as Mirabel finally calls out Abuela for her toxicity for Abuela to acknowledge the trauma of seeing her husband die in front of her and reconcile with her granddaughter after a dazed Mirabel wanders from the rubble.
Turning Red has this for the central conflict. Mei has spent her whole life pleasing her mother Ming but her mind and body start to rebel after Ming humiliates her in front of her crush Devon after accusing him of being a sexual predator. Ming in the meantime remains oblivious to the fact that she's emotionally abusing her only daughter while thinking she's helping out and shaming her for the crime of being a teenager...because Ming's own mother did the same to her. It's implied this emotional abuse and shaming runs several generations back. Her mother didn't even approve of Jin, Ming's Nice Guy of a husband, and is quick to berate Ming if Mei appears less than perfect. The climax features Ming's mother seeing the consequences of her abuse when Ming's panda talisman cracks and she becomes a kaiju-red panda, endangering an entire crowd at the 4*Town concert where Mei ran to reconcile with her friends, and manhandling her daughter painfully.
It's implied in The Croods that part of the reason that Grug and his mother-in-law don't get along is because of this. All of the humans, cavemen and Guy alike, have to work hard to survive in a hostile world. Gran was married off to someone she didn't love and never saw the hunter that she wanted to marry again. She's a good mother to her daughter Ugga and raised her to be a sensible woman, but she hates Grug for the mere fact that he's married to Ugga. Grug was raised to fear everything to protect the ones that he loved. While Gran doesn't hate Grug, and grudgingly admits that he won her respect by pulling a Heroic Sacrifice at the end of the film to save everyone else, she does have it out for him when he's just doing what he's supposed to do: hunt for food and parent.

Literature

Like Water for Chocolate shows how Mama Elena's abuse passes to her children and grandchildren. Her baggage is she wasn't allowed to be with the man she loved because he was a "Moor" and lower-class; she married a man who would financially provide for her but died of shock when he heard rumors about the affair, and that daughter Gertrudis may not be his. A single parent and stigmatized, Elena took out her rage on the only person that she could: her youngest daughter Tita, who per tradition would take care of Elena for the latter's days rather than get married. She forbids Tita from marrying her love Pedro, persuading Pedro to marry her eldest daughter Rosaura instead, and proceeded to berate Tita for protesting this decision for years on end. While Rosaura agrees this is unfair, and she and Tita call a truce later in life after Elena dies, she's shocked when Tita refuses to abide by the truce after learning that Rosaura will hold her daughter to the same tradition.
Middlesex is all about tracing this back to Cal's grandparents, who in the first part are revealed to be brother and sister as well as refugees of a war on the Greeks. No one on the American rescue ship knows who they are, so they are able to cover up their relations and their cousin Lina who takes them in also keeps their secret. They also bring their biases with them, with Milton being raised to fear racial integration and value keeping high amounts of money while his son Chapter Eleven becomes a hardcore liberal. Both of these facts end up playing into Cal's conception and birth; even though Cal is born as Calliope and appears to be a girl, Cal is actually intersex thanks to the genetics and does not learn about this fact until they're fourteen. This sparks an identity crisis when a doctor wants to operate on Cal without telling them or their parents the truth, and Cal runs away, cutting their long hair and dressing as a boy.
Every problem in the Buendía clan in One Hundred Years of Solitude can be easily traced to founding patriarch José Arcadio Buendía's propensity to violence and inability to actually parent his children and to his wife Úrsula's incest paranoia. Is not just that the traits are repeating and reappearing like their descendant names, is that each new generation is replicating what they had learned from the previous one.
The Xeelee Sequence is based largely on humanity as a whole suffering from this. After suffering two horrific alien invasions, which resulted in the Unpersoning of all mankind not just biologically and culturally but right down to Earth's fossil and geological record, humanity was forced to build itself back up from nothing but a burning desire to Never Be Hurt Again, even if that meant killing any and all other alien races.

Live-Action TV

Brooklyn Nine Nine reveals that Jake Peralta comes from a line of crappy fathers. Each one passed on their trauma to the next generation. It's part of the reason why Jake is scared of having kids, that he will pass on the Peralta garbage.

Newspaper Comics

Played for Laughs the few times it's mentioned in Calvin and Hobbes. When Calvin misbehaves at the doctor's office because he hates being sick in the summer and fears his deadpan pediatrician, his mother remarks that she hopes Calvin has a kid one day as bad as he is. Calvin says snarkily, "Yeah that's what Grandma says she told you." Given that Grandma is a Deadpan Snarker as shown by her way of getting Calvin to write thank-you letters for any presents that she sends, it may explain a lot about why Mom is so uptight.
If you read For Better or For Worse from beginning to end, this may be a generous interpretation of the Pattersons. Elly and John are old-fashioned by modern standards but believe they are good parents that happen to have mischievous children. When April wanders outside with family dog Farley after asking them for permission, neither of them realizes they should have been paying attention to their toddler daughter. While John was on the phone and had a legitimate excuse, Elly was showing off vacation photos and lacks one. Most of the aftermath is focused on April's guilt since Farley died rescuing her from the river due to an old heart, and how the family is dealing with Farley's absence, rather than the fact that John and Elly were inattentive at the wrong time. Their kids are encouraged to settle down in the same town and marry their childhood sweethearts after college, ideally not trying groundbreaking careers. Liz gives up a promising job as a teacher to work in a gardening store after her pilot boyfriend cheats on her, a decision which leads to a coworker assaulting and nearly raping her at work despite her punching him in the face several times. When Michael grows up and has two kids, he has moments where he wonders if this was how Elly felt when Meredith becomes overly demanding and if he just became his dad. April is the Only Sane Woman that calls out Anthony for emotionally cheating on his wife Therese to pursue her big sister, and her parents for wanting to move to a smaller house without considering her feelings since she also lives in their house; she's the only Patterson that breaks the cycle by moving to the countryside as a vet and settling down with someone in the area.

Oral Tradition, Folklore, Myths and Legends

Ramayana has a lot of conflict starting because of this trope. Dasharatha has three wives, with Kausalya being the favored one though he loved Sumitra and Kaikeyi, and four sons. When he prepared to crown Kausalya's son Rama, the avatar of Vishnu, Kaikeyi's maid Manthara convinced her to use two boons that Dasharatha gave Kaikeyi to exile Rama and his wife Sita for fourteen years, and crown Kaikeyi's son Bharata. Everyone is aghast at this, including Bharata, but Rama accepts this readily. During this exile, however, King Ravana of Sri Lanka kidnaps Sita and refuses to return her to Rama; Hanuman offers to escort her personally but Sita is worried about her honor. Even though it's proven she never gave into Ravana forcefully trying to marry her through the subsequent war, Rama feels pressured by gossip in his kingdom after his exile ends to banish her, just as she's pregnant with their sons. While the boys never know their father and Sage Valmiki raises them after finding Sita in the woods, they say that Rama sounds like a cruel man when Valmiki tells them an abridged story with the names changed. When years later the boys and Rama fight to a standstill, because Rama sent out a sacrificial horse and the boys thought it would be fun to fight for a white horse, Rama is shocked to see Sita again. He tries to apologize and invite her back to the kingdom; she refuses and calls him out for letting gossip repeat the cycle that got them banished in the first place, before asking the Earth, her mother to swallow her. All Rama can do is take the boys back to his kingdom; shortly after he and his brothers commit suicide by walking into a river after Durvasa curses Lakshmana and barges into Rama's chambers.
Mahabharata: The great war that makes up most of the saga starts because of this. Duryodhana's father is blind and weak-willed, leading to Duryodhana becoming spoiled rotten and entitled, albeit a man with principles that rewards loyalty. Princess Kunti uses a boon thoughtlessly as a teen, which led to Surya impregnating her and Kunti abandoning the baby. This child, raised by charioteers who always wanted a son, would become Duryodhana's right-hand man Karna after the latter made him the crown prince of Anga so he could qualify for an archery tournament. Her later children via the boon also end up being spoiled and entitled since she's married as an adult, especially Arjuna; Krishna has to step in once in a while to break Arjuna's haughtiness. Because of his promise to Duryodhana after the latter makes him a prince, Karna refuses to reveal that he is the rightful heir to the kingdom when Kunti recognizes him and reveals that she's his mother in an attempt to stop a war where Duryodhana wants to rule the brothers' kingdom and cede nothing to them. All Kunti can do is watch in horror as the bloodbath starts and knowing it started with her. The Pandavas themselves are horrified when she reveals the truth to them after the war after she begs them to give Karna a proper funeral. Oh, and in this war, Yudhisthira lies to Drona that his son Aswathamma is dead on Krishna's orders, so Drona willingly dies of despair; to avenge his father, the real Aswathamma wipes out the innocent Pandava children, where only one survives.
In The Bible, this is basically King David's story. He forms a friendship with King Saul and Prince Jonathan after playing the harp for Saul, saves the kingdom from Goliath, and pledges loyalty to the kingdom. Jonathan is more than fine with the idea of David inheriting the kingdom because he sees that David is a good man, but Saul isn't. Cue Saul starting to hunt down his harpist, and Jonathan sent David into hiding because he points out that David has committed no crime other than earning the love of the people. When Jonathan and Saul died in battle along with any heirs to the throne, David becomes king. It seems all is well...but then he spies on Bathsheba, who is married, and decides he wants her. Cue her being pregnant, and Uriah doesn't return home in time to claim the baby as his. David sends her husband Uriah to die and pressures Bathsheba to marry him. Nathan the prophet warns that as a result, their first baby will die, and David's other sons start a civil war because they understandably don't want Solomon to take their birthright. David mourns that his actions ruined his family, and only moves to rule because that is his duty. When Solomon manages to get to the throne, his way to avoid his father's tendency toward infidelity and have a better chance for a worthy heir is by making an harem and marrying as many women as possible, which while giving him less grief while he is alive creates an even bigger succession crisis after his death.

Theatre

It's implied to be the reason why people become messed up in Hatchetfield if there isn't a supernatural reason. Some of the Nightmare Time episodes show that you don't need supernatural beings to corrupt people; human beings are corrupt already. Jerkass and emotionally abusive Linda Monroe treats everyone like garbage (including her husband Gerald who loves her) because she's a backstabbing opportunist, and only favors her son River. Turns out her dad treats her exactly the same way, as "Honey Queen" reveals. She enters the Honey Queen pageant to win his approval, even as Gerald warns her that the senior Mr. Murray isn't worth it.

Visual Novels

Umineko: When They Cry has the Ushiromiya clan, who all suffer one way or another the consequences of the traumas of current patriarch Kinzo. The man was emotionally abused while growing up, forced to become the head of the family after practically every other male adult died in the 1928 Tokyo earthquake, and roped into an arranged marriage he disliked and only consummated to get heirs, but none of the children he had with his legitimate wife was good enough to him. It's implied that the man joined the Imperial army during WWII less of a patriotic feeling and more to get away from his wife and children. Abroad he met his true love, but because of the times, he couldn't divorce his wife and had to keep her as his mistress until she died in childbirth. His legitimate children were raised under various levels of parental abuse on his side, having to bear western names, and developed several unhealthy coping mechanisms themselves: Krauss tends to go towards risky business to the point of getting frequently conned, Eva is a perfectionist that tried to compensate not being taken in account due to Heir Club for Men, Rudolph is a womanizer, and Rosa, the most abused child, gets herself involved with unattainable men and abuses her own kid in turn. His grandchildren are slightly better adjusted due to most of them not being outright abused (and the one who actually is has developed quite creepy coping mechanisms), but they still feel under the heavy eye of their grandfather and their parents' neuroses. And let's not talk about how he raised his illegitimate daughter in such a way she never knew Kinzo was her father, so he could sexually abuse her due to her strong resemblance to her mother, and how the child born from that relationship has to be raised hidden from him to avoid getting the same fate...

Western Animation

Avatar: The Last Airbender practically runs on this trope. A hundred years ago, Avatar Roku's death provided a window of opportunity for the Fire Nation to launch global colonialization on the other kingdoms, under the guise of "improving" them. While the instigator Firelord Sozin had good intentions initially, he realized too late that wiping out all the Airbenders in search of Aang was not going to win him any brownie points or spiritual karma. Each generation of his descendants became worse than the last, with Azulon willing to murder his grandchildren to make a point, and Ozai showing no compunctions about scarring his fourteen-year-old son in front of an Agni Kai audience when said son refused to fight him. It's no wonder that Zuko is a Jerkass after suffering that, and his redemption only starts in season 3 when his imprisoned uncle gives him scrolls of Sozin's diaries, that show where his great-great-grandfather went wrong.
- Legend of Korra continues this with the new blood:
  - Avatar Aang was a good person, a cheerful guy, and a doting father, but Tenzin felt immense pressure from Aang since they were the last two Airbenders in existence. Aang couldn't forget that he was the only survivor of the Airbender clans, having found many skeletons where he expected to find friends, and passed that anxiety onto his only airbending child. Kya and Bumi felt that they were ignored in favor of Tenzin, and both resented their little brother while still showing they would protect him with their life.
  - Firelord Izumi and her son General Iroh bear the emotional scars of what their ancestors did. Iroh leads fleets to protect the innocent while knowing the implications of declaring war. Izumi herself refuses to launch preemptive strikes against Kuvira in Season 4, pointing out that decisions like that led to the Fire Nation destroying entire cultures.
  - Toph Beifong was raised in an over-sheltered manner and hated it, so when she decided to have children she went for Hands-Off Parenting instead. The result was that her two daughters, Lin and Suyin, felt practically abandoned by her mother and rebelled in rather opposite ways, Lin by becoming overly strict in both her private life and as a police officer, and Suyin by briefly foraying with gangs before becoming the head of a free-thinking coven of metalbenders, unwittingly raising the charismatic villain of the last season.
In Gravity Falls, Stan clearly favors Mabel over Dipper as shown in "Dreamscaperers". He gives her more leeway while making Dipper do the nasty chores like shooing a bat out of the kitchen. We soon find out why: his father did the same to him, as a means to toughen him up so that Stan could face the world. Stan thinks that being hard on Dipper means that the world can't knock down his grand-nephew. It gets darker in "A Tale of Two Stans" and the graphic novel: Filbrick Pines was an emotionally abusive man who always picked on Stan for being the screwup goofball while planning to ride on Ford's coattails after the latter proved he was a genius in school. When Stan accidentally sabotaged Ford's project that would have earned him admission to this world's university of Stanford, Ford busted him and believed it was deliberate. Filbrick's response was to kick out his underage son before the latter even finished high school, and Ford never gave Stan a chance to explain himself out of belief that his brother betrayed him for a childhood dream. The implications are that Shermy, the twins' grandfather, was too little to pass on the trauma to the kids since he was a baby when Filbrick kicked Stan out of the house. It takes until the season 2 finale for both brothers to realize their selfishness will get Dipper and Mabel killed, and Ford starts regretting that he took his brother for granted when Stan pulls a Heroic Sacrifice and allows Ford to erase his mind to stop Bill.

Real Life

This psychological phenomenon has been observed many times in real life. If an group suffers a trauma, including violence or displacement, the next generation bears the emotional scars that their parents develop.
Even pregnant parents can pass on stress to their children. This is referred to as transgenerational stress inheritance according to Wikipedia.
The lingering effects of slavery and Jim Crow laws on post-abolition succeeding generations of black Americans, as well as what if any affirmative action and reparation should be made for it, remain a contentious issue.
Many of modern China's actions on the world stage are informed by the Century of Humiliation.