Incest is sexual intercourse between close relatives.^[1][2] The term may apply to sexual activities between: individuals of close "blood relationship"; members of the same household; step relatives related by adoption or marriage; and members of the same clan or lineage.^[3]

The incest taboo is and has been one of the most common of all cultural taboos, both in current nations and many past societies,^[4] Most modern societies have laws regarding incest or social restrictions on closely consanguineous marriages.^[5] In some societies, such as those of Ancient Egypt and others, brother–sister, father–daughter, and mother–son, cousin-cousin, uncle-niece, aunt-nephew, and other permutations of relations were practiced among royalty as a means of perpetuating the royal lineage.^[6][7] In addition, the Balinese^[8] and some Inuit tribes^[9] have altogether different beliefs about what constitutes illegal and immoral incest. However, parent-child and sibling-sibling unions are almost universally forbidden.^[10]

Consensual adult incest is seen by some as a victimless crime.^[11][12] However, children born of close incestous unions have greatly increased risk of death and disability at least in part due to genetic diseases caused by the inbreeding.^[13]

Terminology[link]

The English word incest is derived from the Latin incestus, which has a general meaning of "impure, unchaste". It was introduced into Middle English, both in the generic Latin sense, and in the narrow modern sense. The generic Latin sense preserved throughout the Middle English period.^[14] The derived adjective incestuous appears in the 16th century.^[15] Prior to the introduction of the Latin term, incest was known in Old English as sibbleger (from sibb 'kinship' + leger 'to lie') or mǣġhǣmed (from mǣġ 'kin, parent' + hǣmed 'sexual intercourse') but in time, both words fell out of use.

History[link]

Table of prohibited marriages from The Trial of Bastardie by William Clerke. London, 1594

Antiquity[link]

In ancient China, first cousins with the same surnames (i.e., those born to the father's brothers) were not permitted to marry, while those with different surnames (i.e., maternal cousins and paternal cousins born to the father's sisters) were.^[16]

According to the Biblical Book of Genesis, the Patriarch Abraham and his wife, Sarah were half-siblings, both being children of Terah (Ge 20:12).

The fable of Oedipus, with a theme of inadvertent incest between a mother and son, ends in disaster and shows ancient taboos against incest as Oedipus is punished for incestuous actions by blinding himself. In the "sequel" to Oedipus, Antigone, his four children are also punished for their parents having been incestuous.

Incest appears in the commonly accepted version of the birth of Adonis, when his mother, Myrrha has sex with her father, Cinyras, during a festival, disguised as a prostitute.

Incest is mentioned and condemned in Virgil's Aeneid Book VI:^[17] hic thalamum invasit natae vetitosque hymenaeos; "This one invaded a daughter's room and a forbidden sex act".

It is generally accepted that sibling marriages were widespread among all classes in Egypt during the Graeco-Roman period. Numerous papyri and the Roman census declarations attest to many husbands and wives being brother and sister.^{[18][19][20][21]} The most well known of these relationships were in the royal family, the Ptolemies; The famous Cleopatra VII was married to her younger brother, Ptolemy XIII. Her mother and father, Cleopatra V and Ptolemy XII, had also been brother and sister.

In Ancient Greece, Spartan King Leonidas I, hero of the legendary Battle of Thermopylae, was married to his niece Gorgo, daughter of his half brother Cleomenes I. Greek law allowed marriage between a brother and sister if they had different mothers. For example, some accounts say that Elpinice was for a time married to her half-brother Cimon.^[22]

Incestuous unions were frowned upon and considered as nefas (against the laws of gods and man) in ancient Rome. In AD 295 incest was explicitly forbidden by an imperial edict, which divided the concept of incestus into two categories of unequal gravity: the incestus iuris gentium, which was applied to both Romans and non-Romans in the Empire, and the incestus iuris civilis, which concerned only Roman citizens. Therefore, for example, an Egyptian could marry an aunt, but a Roman could not. Despite the act of incest being unacceptable within the Roman Empire, Roman Emperor Caligula is rumored to have had sexual relationships with all three of his sisters (Julia Livilla, Drusilla, and Agrippina the Younger).^[23] Emperor Claudius, after executing his previous wife, married his brother's daughter Agrippina the Younger, and changed the law to allow an otherwise illegal union.^[24] The law prohibiting marrying a sister's daughter remained.^[25] The taboo against incest in Ancient Rome is demonstrated by the fact that politicians would use charges of incest (often false charges) as insults and means of political disenfranchisement.

Middle Ages[link]

Many European monarchs were related due to political marriages, sometimes resulting in distant cousins (and even first cousins) being married. This was especially true in the Habsburg, Hohenzollern, Savoy and Bourbon royal houses. Incestuous marriages were also seen in the royal houses of ancient Japan and Korea.^[26] Half-sibling marriages were found in ancient Japan such as the marriage of Emperor Bidatsu and his half-sister Empress Suiko.^[27] Japanese Prince Kinashi no Karu had sexual relationships with even his full sister Princess Karu no Ōiratsume, although the action was regarded as foolish.^[28] In order to prevent the influence of the other families, a half-sister of Korean Goryeo Dynasty monarch Gwangjong became his wife in the 10th century.^[29] Brother sister marriages were common during some Roman periods as some census records have shown.^[30]

Prevalence and statistics[link]

Incest between adults and those under the age of consent is considered a form of child sexual abuse^[31][32] that has been shown to be one of the most extreme forms of childhood abuse, often resulting in serious and long-term psychological trauma, especially in the case of parental incest.^[33] Prevalence is difficult to generalize, but research has estimated 10–15% of the general population as having at least one such sexual contact, with less than 2% involving intercourse or attempted intercourse.^[34] Among women, research has yielded estimates as high as 20%.^[33]

Father-daughter incest was for many years the most commonly reported and studied form of incest.^[35][36] More recently, studies have suggested that sibling incest, particularly older brothers having sexual relations with younger siblings, is the most common form of incest,^{[37][38][39][40][41][42][43][44][45]} with some studies finding sibling incest occurring more frequently than other forms of incest.^[46] Some studies suggest that adolescent perpetrators of sibling abuse choose younger victims, abuse victims over a lengthier period, use violence more frequently and severely than adult perpetrators, and that sibling abuse has a higher rate of penetrative acts than father or stepfather incest, with father and older brother incest resulting in greater reported distress than stepfather incest.^[47][48][49]

Types[link]

Between adults and children[link]

Incest between an adult and a child is a form of child sexual abuse^[50] and for many years has been the most reported form of incest. Father–daughter and stepfather–stepdaughter incest is the most commonly reported form of adult-child incest, with most of the remaining involving a mother or stepmother.^[51] Father–son incest is reported less often, although it is not known whether the prevalence is less because it is under-reported by a greater margin.^[52][53] Prevalence of incest between parents and their children is difficult to assess due to secrecy and privacy; some estimate that 20 million Americans were, as children, subjected to incest by a parent.^[51]

According to the National Center for Victims of Crime a large proportion of rape committed in the United States is perpetrated by a family member:

Research indicates that 46% of children who are raped are victims of family members (Langan and Harlow, 1994). The majority of American rape victims (61%) are raped before the age of 18; furthermore, 29% of all rapes occurred when the victim was less than 11 years old. 11% of rape victims are raped by their fathers or step-fathers, and another 16% are raped by other relatives.^[54]

A study of victims of father–daughter incest in the 1970s showed that there were "common features" within families before the occurrence of incest: estrangement between the mother and the daughter, extreme paternal dominance, and reassignment of some of the mother's traditional major family responsibility to the daughter. Oldest and only daughters were more likely to be the victims of incest. It was also stated that the incest experience was psychologically harmful to the woman in later life, frequently leading to feelings of low self-esteem, unhealthy sexual activity, contempt for other women, and other emotional problems.^{[55][clarification needed (needs a better source)]}

Adults who as children were incestuously victimized by adults often suffer from low self-esteem, difficulties in interpersonal relationships, and sexual dysfunction, and are at an extremely high risk of many mental disorders, including depression, anxiety, phobic avoidance reactions, somatoform disorder, substance abuse, borderline personality disorder, and complex post-traumatic stress disorder.^[33][56][57]

The Goler clan is a specific instance in which child sexual abuse in the form of forced adult/child and sibling/sibling incest took place over at least three generations. ^[58] A number of Goler children were victims of sexual abuse at the hands of fathers, mothers, uncles, aunts, sisters, brothers, cousins, and each other. During interrogation by police, several of the adults openly admitted to engaging in many forms of sexual activity, up to and including full intercourse, multiple times with the children. Sixteen adults (both men and women) were charged with hundreds of allegations of incest and sexual abuse of children as young as five.^[58]

Between childhood siblings[link]

Childhood sibling–sibling incest is considered to be widespread but rarely reported.^[51] It is believed to be the most common form of intrafamilial abuse.^[59]

Sibling-sibling incest becomes child-on-child sexual abuse when it occurs without consent, without equality, or as a result of coercion. The most commonly reported form of abusive sibling incest is abuse of a younger sibling by an older sibling.^[51] A 2006 study showed a large portion of adults who experienced sibling incest abuse have distorted or disturbed beliefs (such as that the act was "normal") both about their own experience and the subject of sexual abuse in general.^[60]

Sibling abusive incest is most prevalent in families where one or both parents are often absent or emotionally unavailable, with the abusive siblings using incest as a way to assert their power over a weaker sibling.^[61] Absence of the father in particular has been found to be a significant element of most cases of sexual abuse of female children by a brother.^[62] The damaging effects on both childhood development and adult symptoms resulting from brother–sister sexual abuse are similar to the effects of father–daughter, including substance abuse, depression, suicidality, and eating disorders.^[62][63]

Between consenting adults[link]

Sexual activity between adult close relatives may arise from genetic sexual attraction.^[64] This form of incest has not been widely reported in the past, but recent evidence has indicated that this behavior does take place, possibly more often than many people realize.^[64] Internet chatrooms and topical websites exist that provide support for incestuous couples.^[64]

Proponents of incest between consenting adults draw clear boundaries between the behavior of consenting adults and rape, child molestation, and abusive incest.^[64] According to one incest participant who was interviewed for an article in The Guardian:

"You can't help who you fall in love with, it just happens. I fell in love with my sister and I'm not ashamed ... I only feel sorry for my mom and dad, I wish they could be happy for us. We love each other. It's nothing like some old man who tries to fuck his three-year-old, that's evil and disgusting ... Of course we're consenting, that's the most important thing. We're not fucking perverts. What we have is the most beautiful thing in the world."^[64]

In Slate Magazine, William Saletan drew a legal connection between gay sex and incest between consenting adults.^[65] As he described in his article, in 2003, U.S. Senator Rick Santorum commented on a pending U.S. Supreme Court case involving sodomy laws (primarily as a matter of Constitutional rights to Privacy and Equal Protection under the Law). He stated: "If the Supreme Court says that you have the right to consensual sex within your home, then you have the right to bigamy, you have the right to polygamy, you have the right to incest, you have the right to adultery."^[65] However, David Smith of the Human Rights Campaign professed outrage that Santorum placed being gay on the same moral and legal level as someone engaging in incest. Saletan argued that, legally and morally, there is essentially no difference between the two, and went on to support incest between consenting adults being covered by a legal right to privacy.^[65] UCLA law professor Eugene Volokh has made similar arguments.^[66] In a more recent article, Saletan said that incest is wrong because it introduces the possibility of irreparably damaging family units by introducing "a notoriously incendiary dynamic—sexual tension—into the mix"^[67]

Between adult siblings[link]

The most public case of consensual adult sibling incest in recent years is the case of a brother-sister couple from Germany, Patrick Stuebing and Susan Karolewski. Because of violent behavior on the part of the father, the brother was taken in at the age of 3 by foster parents, who adopted him later. At the age of 23 he learned about his biological parents, contacted his mother, and met her and his then 16 year old sister for the first time. The now-adult brother moved in with his birth family shortly thereafter. After their mother died suddenly six months later, the couple became intimately close, and had their first child together in 2001. By 2004, they had four children together: Eric, Sarah, Nancy, and Sofia. The public nature of their relationship, and the repeated prosecutions and even jail time they have served as a result, has caused some in Germany to question whether incest between consenting adults should be punished at all. An article about them in Der Spiegel states that the couple are happy together. According to court records, the first three children have mental and physical disabilities, and have been placed in foster care. However, Susan herself is mentally slow, which may explain the disabilities, but there is still debate over if their disabilities are from incest or their genetics.^[11] In April 2012, at the European Court of Human Rights, Patrick Stuebing lost his case that the conviction violated his right to a private and family life.^[68][69]

Cousin relationships[link]

Marriages and sexual relationships between first cousins are stigmatized as incest in western cultures. In modern secular law, notably some US states, prohibit marriages between first cousins. Currently, 24 states prohibit such marriages, and another seven permit them only under special circumstances.^[70] Cousin marriages while not illegal are highly stigmatized except in the Middle East, North Africa and other parts of Asia.^[71] Communities such as the Dhond and the Bhittani of Pakistan clearly prefer marriages between cousins as they ensure purity of the descent line, provide intimate knowledge of the spouses, and ensure that patrimony will not pass into the hands of "outsiders".^[72]

Apart from the partial prohibition in the United States, there are some cultures in Asia which stigmatize cousin marriage, in some instances even marriages between second cousins or more remotely related people. This concerns notably the culture of Korea, and some Hindu communities in India. In South Korea, before 1997, anyone with the same last name and clan were prohibited from marriage. In light of this law being held unconstitutional, South Korea now only prohibits up to third cousins (see Article 809 of the Korean Civil Code). In Western Australia over 500 marriages are between cousins. In a review of 48 studies on the children parented by cousins, most of the babies born to cousins were healthy contrary to the popular perception, with birth defects being 4% of births for consanguineous couples as opposed to 2% for the general population.^[73] Inbreeding over many generations does increase risks however.^{[citation needed]}

Incest defined through marriage[link]

Some cultures include relatives by marriage in incest prohibitions; these relationships are called affinity rather than consanguinity. For example, the question of the legality and morality of a widower who wished to marry his deceased wife's sister was the subject of long and fierce debate in the United Kingdom in the 19th century, involving, among others, Matthew Boulton.^[74][75] In medieval Europe, standing as a godparent to a child also created a bond of affinity.^{[citation needed]} But in other societies, a deceased spouse's sibling was considered the ideal person to marry. The Hebrew Bible forbids a man from marrying his brother's widow with the exception that, if his brother died childless, the man is instead required to marry his brother's widow so as to "raise up seed to him" (taken from Deuteronomy 25:5–6).

Inbreeding[link]

Incest that results in offspring is a form of close inbreeding (reproduction between two individuals with a common ancestor). Inbreeding leads to a higher probability of congenital birth defects because it increases that proportion of zygotes that are homozygous, in particular for deleterious recessive alleles that produce such disorders.^[76] Because most such alleles are rare in populations, it is unlikely that two unrelated marriage partners will both be heterozygous carriers. However, because close relatives share a large fraction of their alleles, the probability that any such rare deleterious allele present in the common ancestor will be inherited from both related parents is increased dramatically with respect to non-inbred couples. Contrary to common belief, inbreeding does not in itself alter allele frequencies, but rather increases the relative proportion of homozygotes to heterozygotes. However, because the increased proportion of deleterious homozygotes exposes the allele to natural selection, in the long run its frequency decreases more rapidly in inbred population. In the short term, incestuous reproduction is expected to produce increases in spontaneous abortions of zygotes, perinatal deaths, and postnatal offspring with birth defects.^[77]

There may also be other deleterious effects besides those caused by recessive diseases. Thus, similar immune systems may be more vulnerable to infectious diseases (see Major histocompatibility complex and sexual selection).^[78]

A 1994 study found a mean excess mortality with inbreeding among first cousins of 4.4%.^[79] Children of parent-child or sibling-sibling unions are at increased risk compared to cousin-cousin unions. Studies suggest that 20-36% of these children will die or have major disability due to the inbreeding.^[13] A study of 29 offspring resulting from brother-sister or father-daughter incest found that 20 had congenital abnormalities, including four directly attributable to autosomal recessive alleles.^[80]

Animals[link]

Many mammal species including humanity's closest primate relatives tend to avoid close inbreeding, especially if there are alternative partners available.^[81] However some chimpanzees have been recorded attempting to mate with their mothers.^[82] Male rats have been recorded engaging in mating with their sisters, but they tend to prefer non-related females over their sisters.^[83]

Livestock breeders often practice controlled breeding to eliminate undesirable characteristics within a population, which is also coupled with culling of what is considered unfit offspring, especially when trying to establish a new and desirable trait in the stock.

In popular culture[link]

Incest is a somewhat popular topic in English erotic fiction; there are entire collections and websites devoted solely to this genre, with an entire genre of pornographic pulp fiction known as "incest novels". This is probably because, as with many other fetishes, the taboo nature of the act adds to the titillation. With the advent of the Internet, even more of this type of fiction is available.

Laws[link]

Incest is illegal in many jurisdictions. The exact legal definition of "incest," including the nature of the relationship between persons, and the types sexual activity, varies by country, and by even individual states or provinces within a country. These laws can also extend to marriage between subject individuals.

In some places, incest is illegal, regardless of the ages of the two partners. In other places, incestuous relationships between two consenting adults (with the age varying by location) are permitted. Such countries where it is permissible and legal, includes the Netherlands and Sweden where incestuous couples must seek government counseling before marriage. The only type of incestuous relationship allowed by law in Sweden is that between half-siblings.^[84]

A jurisdiction's definition of an incestuous relationship will also limit who a person is permitted to marry. Some jurisdictions forbid first-cousins to marry, while others limit the prohibition to brothers, sisters, mothers, fathers, aunts and uncles.

Religious views[link]

Jewish[link]

In three places in the Torah, there are lists of family members between whom it is prohibited to have sexual relations; each of these lists is progressively shorter. The biblical lists are not symmetrical – the implied rules for women are not the same. Relationships compare as follows:

Apart from the questionable case of the daughter, the first incest list in the Holiness code roughly produces the same rules as were followed in early (pre-Islamic) Arabic culture;^[85] in Islam, these pre-existing rules were made statutory.^[86]

In the 4th century BCE, the Soferim (scribes) declared that there were relationships within which marriage constituted incest, in addition to those mentioned by the Torah. These additional relationships were termed seconds (Hebrew: sheniyyot), and included the wives of a man's grandfather and grandson.^[87] The classical rabbis prohibited marriage between a man and any of these seconds of his, on the basis that doing so would act as a safeguard against infringing the biblical incest rules,^[88] although there was inconclusive debate about exactly what the limits should be for the definition of seconds.^[85]

Marriages forbidden in the Torah were regarded by the rabbis of the Middle Ages as invalid – as if they had never occurred;^[89] any children born to such a couple were regarded as Jewish bastards,^[89] and the relatives of the spouse were not regarded as forbidden relations for a further marriage.^[90] On the other hand, those relationships which were prohibited due to qualifying as seconds, and so forth, were regarded as wicked, but still valid;^[89] while they might have pressured such a couple to divorce, any children of the union were still seen as legitimate.^[89]

Christian[link]

In the Roman Catholic Church, marriage is generally not permitted if the potential spouses are related in the collateral line up to and including the second degree, although a dispensation may be granted permitting marriages between first cousins or even uncle/niece unions as in the marriage of Leopold I, Holy Roman Emperor to his niece, and first cousin, Margarita Teresa of Spain in 1666. The Church does not generally permit the marriage if a doubt exists on whether the potential spouses are related by consanguinity in any degree of the direct line or in the second degree of the collateral line.^[91]

In the Eastern Orthodox Church, marriages are banned between second cousins or closer and between second uncles / aunts and second nieces / nephews (between first cousins once removed) or closer. Also, marriages that produce children that are closer genetic relatives than legal are also not permitted (unless the genetic relationship does allow marriage between those children). For example, two siblings may not marry two other siblings because legally their children will be cousins, but genetically they'll be half-siblings. On the other hand, two siblings may marry two cousins.^{[citation needed]}

The Anglican Communion allows marriages up to and including first cousins. But in all of the three preceding Christian churches, marriages to uncles, aunts, relatives in the direct line, or their respective spouses are not allowed.^{[citation needed]}

Islamic[link]

The Quran gives specific rules regarding incest, which prohibit a man from marrying or having sexual relationships with:

The main differences (apart from relationships between a man and his daughter) are:

A Hadith also prohibits marriage to a woman and her parent's sister at the same time.^[94] The same applies for a woman with the male counterparts to the aforementioned.

Hindu[link]

Hinduism speaks of incest in abhorrent terms. Hindus are fearful of the bad effects of incest and thus practice strict rules of both endogamy and exogamy within castes (Varna in Hinduism) but not in the same family tree (gotra) or bloodline (Pravara). Marriages within the gotra ("swagotra" marriages) are banned under the rule of exogamy in the traditional matrimonial system.^[95] People within the gotra are regarded as kin and marrying such a person would be thought of as incest. i.e. Marriage with paternal cousins is strictly prohibited. Marriage with maternal cousins and marriages between uncle and niece were widely in practice.^[96] In fact marriage between two people whose parents are related paternally up to seven generations is expressly prohibited. Gotra is transferred down the male lineage while the Gotra of a female changes upon marriage. i.e., upon marriage a woman belongs to her husband's Gotra and no longer belongs to her father's Gotra.Hence marriage with a person having same Gotra as of the original Gotras of grandparents is prohibited^{[citation needed]}.

Buddhist[link]

Buddhist societies take a strong ethical stand in human affairs and sexual behavior in particular. Most variations of Buddhism decide locally about the details of incest as a wrongdoing, according to local cultural standards.^[97] Sexual misconduct is mentioned but the definition of what constitutes misconduct sex is an individual issue.^[98] The most common formulation of Buddhist ethics are the Five Precepts and the Noble Eightfold Path: one should neither be attached to nor crave sensual pleasure. These precepts take the form of voluntary, personal undertakings, not divine mandate or instruction. The third of the Five Precepts is "To refrain from committing sexual misconduct". 'Sexual misconduct' means any sexual conduct involving violence, manipulation or deceit – conduct that therefore leads to suffering and trouble.^[99] Buddhist priests, monks and nuns strictly forbid any type of sexual misconduct but incest is not specifically defined as sexual misconduct, and therefore depends on the culture of the area, not on mandate from Buddhism itself. However, there are no enforced rules for laypeople in Buddhism, only guidance.^{[citation needed]}

See also[link]

Sexuality portal

• Accidental incest
• Incest in folklore
• Incest in popular culture

References[link]

Notes