History Main / IncestStandardsAreRelative

* ''VideoGame/CrusaderKingsII'': What "counts" as incest and is therefore prohibited depends on characters' religious preference. Eastern Orthodoxy outlaws "avunculate" (aunt-nephew or uncle-niece) marriages, but Roman Catholicism doesn't, and religions with the "Divine Blood" doctrine (Zoroastrianism, Messalianism, and reformed pagan religions depending on player or AI choice in ''Holy Fury'') actively encourage marrying sibling to sibling or parent to child.

Incest is defined as romantic or sexual relations between people sharing a familial connection and is a cultural taboo across different societies. The most common no-no is incest between close blood relatives (i.e. parent/child or sibling/sibling), which is illegal in most countries nowadays. The legality of cases like KissingCousins or non-blood-related incest like WifeHusbandry, NotBloodSiblings, or FlirtyStepsiblings may vary, but those usually still carry a stigma. The exact definition of what counts as family and thus also incest can however be very different across cultures and time periods. A romantic relationship between the following may thus also be defined as incest and taboo:

Incest is defined as romantic or sexual relations between people sharing a familial connection and is a cultural taboo across different societies. The most common no-no is incest between close blood relatives (i.e. parent/child or sibling/sibling), which is illegal in most countries nowadays. The legality of cases like KissingCousins or non-blood-related incest like WifeHusbandry, NotBloodSiblings or FlirtyStepsiblings may vary, but those usually still carry a stigma. The exact definition of what counts as family and thus also incest can however be very different across cultures and time periods. A romantic relationship between the following may thus also be defined as incest and taboo:

* Between people blood-related in a specific way (like between an uncle or aunt and a niece or nephew), through a specific member of the family or by being on the same side or branch of the family. Marriage between family members outside of these specific relations may be seen as fine in that culture (see also the concept of [[https://en.wikipedia.org/wiki/Parallel_and_cross_cousins parallel versus cross-cousin marriage]]).
* Between people who grew up in the same creche, kibbutz or other cultural in-group (see also the concept of the UsefulNotes/WestermarckEffect).

If one or more of these definitions of family is normal or widespread in the culture of the creator of a work, the {{Angst}} and drama caused by this kind of ForbiddenLove may cause ValuesDissonance in readers not brought up with that taboo. Culture-specific incest may also be played for DeliberateValuesDissonance, especially from an outsider POV or in a constructed fantasy culture -- then YourNormalIsOurTaboo is in play. The definition of what counts as incest may also be different for [[RoyalInbreeding royalty]] or [[DivineIncest the divine]] compared to the common folks.

* In one of Fazil Iskander's stories, a person is being blackmailed with a secret so terrible, his son is certain to commit suicide should he learn. The secret is that long ago, before the son married, his father and his future mother-in-law used to be lovers. Both were widowed at the time, and there were no children born from the affair, but still makes their kids' marriage incest by Abkhasian standards.

* ''{{Literature/Hainish}}'' universe: On planet O, people are divided into "Moieties" known as Evening and Morning, and all of society is built around said moieties. Sexual relationships within a moiety are forbidden. A typical marriage involves two men and two women, one from each moiety. As such, each person has two people he is married to, a man and a woman, who he is supposed to have sex with, and one of the opposite with whom he cannot have sex with. No one in the books ever even considers it.
* ''Literature/TheIngenue'': The titular character cannot marry with Miss de Saint-Yves because she accepted to be his godmother for his bapticism, causing the major part of the intrigue to obtain a Papal dispense.
* ''Literature/JudgeDee'': In "The Chinese Maze Murders", [[spoiler:General Ting's son]] turns out to be having an affair with a married woman his age. Unfortunately, said woman is [[spoiler:his father's concubine]], which is considered as bad as incest even without the (attempted) MurderTheHypotenuse (Ancient China did not like [[spoiler:patricides]], even against an AssholeVictim). The judge orders the man to commit suicide to prevent the family's corruption spreading any further.

* In ''Poltava'' by Creator/AlexanderPushkin, as well as [[Theatre/{{Mazeppa}} the opera based on it]], Kochubey absolutely forbids a marriage between his daughter Maria and Mazeppa first and foremost because Mazeppa is Maria's godfather, so it will be a form of incest. In the opera, Mazeppa points out he can get permission for the marriage from the archbishop[[note]]Which ''is'' possible in Orthodox Christianity in RealLife for godparent/godchild marriages[[/note]], but it doesn't convince Kochubey. Maria runs away with Mazeppa anyway, but their relationship ends in tragedy when Mazeppa has Kochubey killed for political reasons.

* ''Literature/TheWayfarerRedemption'' series: The ruling family of [[WingedHumanoid the Icarii race]], the [=SunSoars=] bear a curse that they will always be drawn -- both romantically and sexually -- to others of their bloodline; LoveCannotOvercome is in full effect for relationships outside the family, which near-invariably fail as their blood, “will crave another [=SunSoar=]”. Although KissingCousins, aunts/nephews & uncles/niece, or even child/grandparent are acceptable (as the LongLived race cease to physically age out of their prime), they nonetheless have a taboo on parent-child or SiblingIncest. A subplot in that latter books reveals that [[spoiler:Caelum, eldest child and heir of Axis and Azhure, was in an illicit relationship with his sister [=RiverStar=] before she was murdered -- supposedly by her own twin, Drago ([[BroughtDownToNormal formerly]] called [=DragonStar=]). When this resulted in her becoming pregnant she pressured him about being open about their relationship, on threat of claiming to their parents that he’d raped her; Caelum, internally struggling between this and his public image, fell into a frenzied rage and stabbed her to death and when Drago caught him in the midst of it, he modified his memories to frame him for the act.]]

** Jacob married the sister of his then-alive wife. Subsequent Israelite standards, codefied in the Book of Leviticus, forbid a man from marrying his wife's sister until the death of his wife. The Book of Numbers says that Amram, father of Moses, married his father's sister, which is also forbidden under the Leviticus code (which was given over 83 years after Amram's marriage).

* The story of [[UsefulNotes/KievanRus Saint Olga]] states that she, when a pagan and a widow, caught the eye of the Emperor Constantine VII. She insisted on being baptised with him as her godfather, giving her grounds to refuse him as his daughter.

* In ''Literature/AlwaysComingHome'', all the Kesh people belong to one of five "Houses", determined by the mother's House. Sex with a member of the same house is a strict taboo. One story describes a man who raped a woman and immediately killed himself, with the author commenting that [[LostInTranslation in the original, untranslated story]], the way he addressed the woman makes it obvious from the start they are from the same House.
* The Free Traders of ''Literature/CitizenOfTheGalaxy'' divide their boats in moieties, crew of sailors treated as relatives among whom no marriage is allowed. For instance, on the ''Sisu'', when Mata grew close with the main character Thorby (who originated from a different culture, and was not blood-related to Mata), the Chief Officer actually sent Mata to another ship, since both belonged to the same moiety.

* On planet O from Ursula K. Le Guin's {{Literature/Hainish}} universe, people are divided into "Moieties" known as Evening and Morning, and all of society is built around said moieties. Sexual relationships within a moiety are forbidden. A typical marriage involves two men and two women, one from each moiety. As such, each person has two people he is married to, a man and a woman, who he is supposed to have sex with, and one of the opposite with whom he cannot have sex with. No one in the books ever even considers it.
* The titular character of ''Literature/TheIngenue'' cannot marry with Miss de Saint-Yves because she accepted to be his godmother for his bapticism, causing the major part of the intrigue to obtain a Papal dispense.

* In ''Literature/PercyJacksonAndTheOlympians'', Percy mentions that since the gods don’t have DNA, the DivineIncest prevalent in Myth/ClassicalMythology is considered acceptable. This means relationships between campers are accepted, and even prevalent. There ''is'' one taboo, though--it’s not acceptable for campers to date someone from their own house (meaning they share a divine parent).

** Avunculate marriage is the blurry edge of incest in Westerosi society. Sibling marriage is definitely forbidden; cousin marriage is definitely allowed. Aunt/uncle and niece/nephew? It's murky. Marriage between the immediate family (most commonly BrotherSisterIncest) was common among dragonriders of Old Valyria to keep the bloodlines pure. When Valyrians Aegon and his two sister-wives arrived in Westeros, their union was in defiance of the doctrines of the native Faith of the Seven, who saw the products of such close incest as abominations. Early in the Targaryen reign, the Faith of the Seven protested the marriage of Maegor and his half-niece Rhaena on the grounds of incest. But there are also examples of native Westerosi couples with the same half-uncle and niece relationship: Edric and Serena Stark, and Jonnel and Sansa Stark.

* In ''Literature/TheStormlightArchive'', the Vorin religion has a taboo against remarrying to a relative of a former spouse, under the perception that in-laws are related. Though Navani and Dalinar clearly care for each other, her prior marriage to his brother Gavilar means this proves an obstacle to their romance, [[spoiler:and even though the literal Stormfather officiates their marriage, it ultimately is a factor in Dalinar's ex-communication from Vorinism.]]

* In ''Literature/WarAndPeace'', Sonya is secretly delighted when Andrey and Natasha reunite because Nikolay can't possibly have an 'incestuous' relationship with Marya; this despite the fact that ''Sonya'' is his blood relation (first cousins), while Marya is only his brother-in-law's sister. Which, to clarify, made her his ''actual'' sister by the standards of the time, while a cousin is just extended family and therefore at least one step removed.
* In ''Literature/TheWayfarerRedemption'' series, the ruling family of [[WingedHumanoid the Icarii race]], the [=SunSoars=] bear a curse that they will always be drawn — both romantically and sexually — to others of their bloodline; LoveCannotOvercome is in full effect for relationships outside the family, which near-invariably fail as their blood, “will crave another [=SunSoar=]”. Although KissingCousins, aunts/nephews & uncles/niece, or even child/grandparent are acceptable (as the LongLived race cease to physically age out of their prime), they nonetheless have a taboo on parent-child or SiblingIncest. A subplot in that latter books reveals that [[spoiler:Caelum, eldest child and heir of Axis and Azhure, was in an illicit relationship with his sister [=RiverStar=] before she was murdered — supposedly by her own twin, Drago ([[BroughtDownToNormal formerly]] called [=DragonStar=]). When this resulted in her becoming pregnant she pressured him about being open about their relationship, on threat of claiming to their parents that he’d raped her; Caelum, internally struggling between this and his public image, fell into a frenzied rage and stabbed her to death and when Drago caught him in the midst of it, he modified his memories to frame him for the act.]]
* In the ''Literature/WhiteIndian'' series, the second El-i-chi is considered by the village matrons to want an incestuous marriage with the daughter of the man his mother married after El-i-chi's father was murdered.
* In one of ''Literature/TheWolfhound'' books, a girl doesn't want the guy chosen for her as a husband. He, thankfully, isn't so keen on the idea either. So the two publicly perform a form of food sharing which, in their society, makes them officially siblings.

-->'''Michelle:''' This is incest!
-->'''James:''' No, it's not.
-->'''Michelle:''' Yes, it is, James.
-->'''James:''' We're not related.
-->'''Michelle:''' Oh, and that makes it okay, I suppose?
-->''' James:''' Well, it makes it ''not incest''.
* ''Series/GilmoreGirls:'' PlayedForLaughs when Lorelai discovers her paternal grandmother's maiden name was also Gilmore. Emily confirms that Trix and her husband were second cousins. Lorelai and Rory are totally [[{{Squick}} squicked out]], and a little perturbed that Emily isn't.
-->'''Emily:''' Oh, don't act so scandalized. It was not at all uncommon for prominent families to keep the bloodlines closed.
-->'''Lorelai:''' Keeping the bloodlines closed. Is that what we're calling it?
-->'''Emily:''' Well, what would you call it?
-->'''Lorelai:''' Oh, I don't know. How about "Good morning, Appalachia, I got a mighty cute sister and an extra set of toes."
-->'''Emily:''' No one has any extra toes.

* On the planet O from Ursula K. Le Guin's {{Literature/Hainish}} universe, people are divided into "Moieties" known as Evening and Morning, and all of society is built around said moieties. Sexual relationships within a moiety are forbidden. A typical marriage involves two men and two women, one from each moiety. As such, each person has two people he is married to, a man and a woman, who he is supposed to have sex with, and one of the opposite with whom he cannot have sex with. No one in the books ever even considers it.

* In ''Poltava'' by Creator/AlexanderPushkin, as well as [[Theatre/{{Mazeppa}} the opera based on it]], Kochubey absolutely forbids a marriage between his daughter Maria and Mazeppa first and foremost because Mazeppa is Maria's godfather, so it will be a form of incest. In the opera, Mazeppa points out he can get a permission for the marriage from the archbishop[[note]]Which ''is'' possible in Orthodox Christianity in RealLife for godparent/godchild marriages[[/note]], but it doesn't convince Kochubey. Maria runs away with Mazeppa anyway, but their relationship ends in tragedy when Mazeppa has Kochubey killed for political reasons.

* In ''Literature/TheStormlightArchive'', the Vorin religion has a taboo against remarrying to a relative of a former spouse, under the perception that in-laws are related. Though Navani and Dalinar clearly care for each other, her prior marriage to his brother Gavilar means this proves an obstacle to their romance, [[spoiler:and even though the literal Stormfather officiates their marriage, it ultimately is a factor in Dalinar's excommunication from Vorinism.]]
* In ''A Time of Changes" by Creator/RobertSilverberg, the narrator has been attracted to his "bondsister", Halum, all his life, even going as far as [[SettleForSibling marrying her very similar looking cousin]]. [[spoiler:Once she learns of his feelings, Halum is so disturbed she is DrivenToSuicide at once.]]

Subtrope to ForbiddenLove.

* In ''Literature/TheStormlightArchive'', the Vorin religion has a taboo against remarrying to a relative of a former spouse, under the perception that in-laws are related. Though Navani and Dalinar clearly care for each other, her prior marriage to his brother Gavilar means this proves an obstacle to their romance, [[spoiler: and even though the literal Stormfather officiates their marriage, it ultimately is a factor in Dalinar's excommunication from Vorinism.]]

[[folder:Mythology and Folklore]]

* On the planet O from {{Literature/Hainish}}, people are divided into "Moieties" known as Evening and Morning, and all of society is built around said moieties. Sexual relationships within a moiety are forbidden. A typical marriage involves two men and two women, one from each moiety. As such, each person has two people he is married to, a man and a woman, who he is supposed to have sex with, and one of the opposite with whom he cannot have sex with. No one in the books ever even considers it.

* Between in-laws (e.g. by marrying your [[RomancingTheWidow dead brother's wife]] or her sister; see also DoubleInLawMarriage)
* Between milk siblings (people nursed by the same woman)
* Between SwornBrothers
* Between people blood-related in a specific way (like between an uncle or aunt and a niece or nephew), through a specific member of the family or by being on the same side or branch of the family. Marriage between family members outside of these specific relations may be seen as fine in that culture (see also the concept of [[https://en.wikipedia.org/wiki/Parallel_and_cross_cousins parallel versus cross-cousin marriage]]).
* Between people who grew up in the same creche, kibbutz or other cultural in-group (see also the concept of the UsefulNotes/WestermarckEffect)
* Between people with a religious or spiritual connection (e.g. one being a godparent to another)
* Between step-siblings, even [[RetroactiveStepsiblingRelationship retroactively]]

[[/folder]]