L''''inceste''' désigne une relation sexuelle entre membres de la même famille et soumise à un interdit. Étymologiquement signifie « impur » (''incestus'')

Toute la difficulté réside dans la définition de ce que sont des parents trop proches, et il y a de grandes variations selon les sociétés et les époques, et même selon les circonstances (la Bible, par exemple montre l’inceste, normalement interdit, comme un impératif pour sauvegarder une lignée vouée sans cela à l’extinction). Il y a une typologie de l'inceste fondée sur le discours social à propos du degré de proximité et le genre de parenté biologique, imaginaire et symbolique, discours social d'où découle le sentiment incestueux. 

Le terme est souvent associé à celui de pédophilie car parmi toutes les relations incestueuses, celles entre un parent et son enfant mineur sont les plus violemment condamnées - bien qu’un incestueux soit rarement pédophile et qu’un pédophile n'abuse pas toujours de ses propres enfants.

Enfin, le terme peut être employé de manière métaphorique en dehors du champ de la sexualité pour décrire la relation entre deux personnes ou entités très proches (par exemple deux entreprises).

===Typologie de l'inceste===

La notion d’inceste est une invention de l'homme. Elle est variable d’une époque à l’autre et d’un groupe social, au service de quelque intérêt. La différence des législations sur l'inceste témoigne de la variation de cette notion, là où elle existe.

===L'inceste et la loi===

====La loi canadienne====

L'article 155 du code criminel définit l’inceste comme suit : « Commet un inceste quiconque, sachant qu’une autre personne est, par les liens du sang, son père ou sa mère, son enfant, son frère, sa sœur, son grand-père, sa grand-mère, son petit-fils, sa petite-fille, selon le cas, a des rapports sexuels avec cette personne.»

====La loi française====

Le terme d'inceste n'est mentionné dans aucun des deux principaux codes (pénal et civil) du droit français. Il a disparu du code pénal après la révolution de 1789. La loi lui a substitué la reconnaissance, comme circonstance aggravante, du fait qu'une agression sexuelle, une atteinte sexuelle ou un viol sur un mineur soit commis par un parent ou tuteur (« ascendant légitime naturel ou adoptif ou toute personne ayant autorité sur la victime »).

Rappelons qu'une atteinte sexuelle qualifie une relation sexuelle consentie ; elle n'est illégale que si elle est commise par un majeur sur un mineur de moins de 15 ans (articles 227-25 à 227-27 du code pénal) ou par une personne (pas nécessairement majeure) ayant autorité sur un mineur de moins de 18 ans, sauf émancipation par mariage ; c'est un délit (jugé devant un tribunal correctionnel). La corruption de mineur (227-22) est un autre délit, qui n'implique ni contacts ni relations sexuelles, mais (entre autres) l'exposition à du matériel pornographique ou à des scènes sexuelles. Une agression sexuelle est une relation sexuelle commise avec violence, contrainte, menace ou surprise (222-22). Enfin un viol est une agression sexuelle comportant une pénétration. C'est un crime, jugé en cour d'assises. Dans tous les cas, il y a des circonstances aggravantes, entre autres si l'auteur a une autorité sur la victime ou si c'est un ascendant n'ayant pas l'autorité. Le consentement est réputé valable à 15 ans (18 si autorité).

En dehors de ces cas, une relation sexuelle incestueuse consentie entre individus majeurs n'est donc pas une infraction.

Le Code civil interdit toutefois le mariage entre parents en ligne directe (article 161), frère et sœur (article 162), oncle et nièce, et tante et neveu (article 163). Il interdit également l’adoption d’un enfant né d’un inceste par son père biologique, si ce père est le frère ou le parent en ligne directe de la mère (article 334-10). Cette disposition permet de ne pas reconnaître la parenté conjointe des incestueux. La Cour de cassation l'a confirmé dans sa jurisprudence (arrêt du 6 janvier 2004).

====La loi suisse====

L'article 213 du code pénal Suisse (livre deuxième, titre sixième) condamne clairement l'inceste en ces termes : 

# L’acte sexuel entre ascendants et descendants, ou entre frères et sœurs germains, consanguins ou utérins, sera puni de l’emprisonnement.
# Les mineurs n’encourront aucune peine s’ils ont été séduits.

====La loi autrichienne====

§ 211 du code pénal autrichien "Blutschande" (traduction littérale : déshonneur du sang)

# Celui qui accomplit l'acte sexuel avec un parent de ligne droite est à punir d'emprisonnement de pas plus d'un an.
# Celui qui séduit une personne, qui est un parent de ligne ascendante ou descendante, à accomplir l'acte sexuel est à punir d'emprisonnement de pas plus de trois ans.
# Celui qui accomplit l'acte sexuel avec son frère ou sa sœur est à punir d'emprisonnement de pas plus de six mois.
# Celui qui n'a pas atteint l'âge de 19 ans lors du crime n'est pas à punir s'il a été séduit.

== Historique ==
Depuis l’Égypte pharaonique et encore récemment dans certains pays comme le Pérou pour la famille des Incas, il était fréquent, dans la noblesse, de se marier et d’avoir des enfants avec un membre plus ou moins éloigné de sa famille. 

Ces mariages consanguins avaient, au moins, différents sens plus ou moins liés : 
* une imitation de caractéristiques divines (Osiris, époux de sa sœur Isis) ;
* une manifestation de puissance (non asservissement aux règles ordinaires) ;
* une concentration de légitimité, assurant aux descendants un maximum d’ancêtres royaux, tout en excluant les autres familles de ces caractéristiques du lignage et, par là, une limitation des risques politiques.

Cette tradition disparaît peu à peu : l’empereur actuel du Japon est le premier de sa dynastie à être marié à une femme ne faisant pas partie de sa famille.

Dans la Rome antique, la violation du serment de chasteté par les vestales était taxé d'''incestus'' et, considéré comme un crime inexpiable, généralement puni par la mort de la coupable, condamnée à être enterrée vivante. Quant à son séducteur, il était fouetté jusqu'à ce que mort s'ensuive...
Mais tous les incestes ne méritaient pas le même sort. Ainsi, bien que présenté comme une exigence du peuple de Rome, le remariage de l'Claude avec sa nièce Agrippine la Jeune était clairement considéré comme incestueux. Pour apaiser les dieux, on s'adonna à quelques rites purificatoires, et le mariage finit par être accepté.

Au Moyen Âge, la parenté spirituelle comptait aussi pour définir l’inceste : toute union parrain-filleule ou marraine-filleul était ainsi prohibée, mais aussi toute union entre un parent (père ou mère) et le parrain ou la marraine de l’un de ses enfants.

L’inceste n’est pas toujours symétrique par rapport au sexe (par exemple : prohibition des relations oncle-nièce sans prohibition des relations tante-neveu).

Les sociétés qui considèrent le père comme quantité négligeable (parfois faute de le connaître) peuvent néanmoins connaître l’inceste (prohibition des relations oncle-nièce, par exemple).

== La prohibition de l'inceste ==

L’inceste est souvent considéré comme criminel, tombant sous un interdit social et pénal et puni par la loi, surtout lorsqu'il est commis sur un mineur sexuel. Dans ce dernier cas, l’inceste a souvent de lourdes conséquences pour la victime — certains parlent de ''meurtre psychique'' — dans son développement psychologique, psycho-affectif et psycho-sexuel. Le caractère de cet interdit a considérablement varié selon les sociétés et les époques mais toujours a existé une loi structurante qui réglemente les unions entre les êtres.

===Dans l'islam===

Le Coran a bien décrit les femmes avec lesquelles le mariage est prohibé à la surate ANNISSAA (IV) verset 22-23 :

« Et n'épousez pas les femmes que vos pères ont épousées, exception faite pour le passé<ref name="passé">Les infractions antérieures à la révélation de ces versets et contraire à ces lois ne seront pas punies.</ref>. C'est une turpitude, une abomination, et quelle mauvaise conduite ! »

« Vous sont interdites vos mères, filles, sœurs, tantes paternelles et tantes maternelles filles d'un frère et filles d'une sœur, mères qui vous ont allaités, sœurs de lait, mères de vos femmes, belles-filles sous votre tutelle et issues des femmes avec qui vous avez consommé le mariage ; si le mariage n'a pas été consommé, ceci n'est pas un péché de votre part ; les femmes de vos fils nés de vos utérus ; de même que deux sœurs réunies — exception faite pour le passé<ref name="passé" />. Car vraiment Allah est Pardonneur et Miséricordieux ; »

On note que l'Islam interdit en ligne directe le mariage entre ascendants et descendants à l'infini. En ligne collatérale, l'interdiction touche les frères et sœurs, nièces et oncles, neveux et tantes. Néanmoins, le mariage est permis entre cousins. Les prohibitions résultant de la parenté du lait sont les mêmes que celles de la parenté ou de l'alliance mais seul l'enfant allaité<ref>L'allaitement ne sera considéré que si l'âge de l'enfant ne dépasse pas les vingt-quatre mois (حولين كاملين) « ''CORAN'' »</ref> est considéré comme enfant de la nourrice et de son époux, à l'exclusion de ses frères et sœurs.

<references />

===Dans la Bible===

'''Incest''' is sexual activity between closely related persons (often within the immediate family) that is illegal or socially taboo. The type of sexual activity and the nature of the relationship between persons that constitutes a breach of law or social taboo vary with culture and jurisdiction.

The most frequently reported type of incest is father-daughter incest.<ref name=Herman></ref> Incest between adults and prepubescent or adolescent children is a form of child sexual abuse<ref name= Wolf170/> that has been shown to be one of the most extreme forms of childhood trauma, a trauma that often does serious and long-term psychological damage, especially in the case of parental incest.<ref name= Courtois></ref> Prevalence is difficult to generalize, but research has estimated 10-15% of the general population as having at least one incest experience, with less than 2% involving intercourse or attempted intercourse.<ref></ref> Among women, research by Russell (1986) and Wyatt (1985) has yielded estimates as high as twenty percent.<ref name= Courtois/> 

Adults who were incestuously victimized by adults in their childhood often suffer from low depression, anxiety, phobic avoidance reactions, somatoform disorder, substance abuse, borderline personality disorder, and complex post-traumatic stress disorder.<ref name= Courtois/><ref></ref><ref></ref> 

Consensual mutually desired adult incest is very rare, found almost exclusively between kin who were separated early in life and therefore did not experience early association and the related development of the natural adaptation for incest avoidance.<ref name= Wolf170></ref>
Consensual incest between adults is criminalized in most countries, although it is seen by some as a victimless crime.<ref name="spiegel"></ref>

Incest is sexual activity between family members of either sex and age, with or without consent (depending on local laws, especially age of consent). However, which family members constitute those covered by the incest prohibition is determined by the society in which the persons live. Some societies consider it to include only those who live in the same household, or who belong to the same clan or lineage; other societies consider it to include "blood relatives"; other societies further include those related by adoption or marriage.<ref>''Elementary Structures Of Kinship,'' by Claude Lévi-Strauss. (tr.1971).</ref>

Most societies have some form of incest avoidance.<ref>Brown, Donald E., ''Human Universals''. New York: McGraw-Hill, 1991, p. 118-29</ref><ref name=Turner></ref> The incest taboo is and has been one of the  most common of all cultural taboos, both in current nations and many past societies,<ref>''Incest: The Nature and Origin of the Taboo,'' by Emile Durkheim (tr.1963)</ref> with legal penalties imposed in some jurisdictions. Most modern societies have legal or social restrictions on closely consanguineous marriages.<ref>''Kinship, Incest, and the Dictates of Law,'' by Henry A. Kelly, 14 Am. J. Juris. 69</ref> However, in some societies, such as that of Ancient Egypt, brother–sister, father–daughter, and mother–son relations were practiced among royalty.<ref>Maurice Godelier, Métamorphoses de la parenté, 2004</ref><ref></ref> In addition, the Balinese<ref name= Bateson></ref> and some Inuit tribes<ref name=JBriggs></ref> have altogether different beliefs about what constitutes illegal and immoral incest.

==Types==
===Between adults and children===

Incest perpetrated by an adult of either gender against a child is called "intrafamilial child sexual abuse". The most-often reported form of incest is of this inherently abusive form. Father-daughter and stepfather-daughter incest is most commonly reported, with most of the remaining reports consisting of mother/stepmother-daughter/son incest.<ref name=Turner /> Father-son incest is reported less often, however it is not known if the prevalence is less, because it is under-reported by a greater margin.<ref></ref><ref></ref> Prevalence of parental child sexual abuse is difficult to assess due to secrecy and privacy;  some estimates show 20 million Americans have been victimized by parental incest as children.<ref name=Turner />

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:
<blockquote>Research indicates that 46 percent (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 percent (29%) of all forcible rapes occurred when the victim was less than 11 years old. Eleven percent (11%) of rape victims are raped by their fathers or step-fathers, and another 16 percent (16%) are raped by other relatives. <ref>
</ref></blockquote>

Emotional incest occurs when a parent relates to a child as a substitute for an adult partner. That child may become emotionally bonded to, and codependent with, the parent. Emotional incest usually occurs before physical parent-child incest. Even without physical sexual contact, the consequences to such "bonded" children include a lifetime of partnership difficulties, according to Martyn Carruthers who wrote that this is a socially accepted form of child abuse in many countries.<ref>[http://www.soulwork.net/sw_articles_eng/emotional_incest.htm EMOTIONAL INCEST]</ref>

A study of victims of father-daughter incest in the 70s showed that there were "common features" within families prior to the occurrence of incest: estrangement between the mother and the daughter, extreme paternal dominance, the mother's inability to fulfill her traditional parental role and reassignment of some of the mother's major family responsibility to the daughter. Oldest and only daughters were more likely to be the victims of incest. Furthermore, it was 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<ref>Emotional Inheritance: A Dubious Legacy. (May 21, 1977). ''Science News, 111'' (21), 326.</ref>.

The ISNA reported that a counselling hotline stated that a large percentage of the calls they handle deal with the issue of parental child abuse.<ref> </ref>

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. <ref name="cruise">Cruise, David, and Griffiths, Alison. ''On South Mountain: The Dark Secrets of the Goler Clan'' (Penguin Books, 1998) ISBN 0670873888</ref>  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.<ref name="cruise" />

===Between childhood siblings===
Many types of sexual contact between children (e.g., "playing doctor") are not considered harmful or abnormal, but become child-on-child sexual abuse when there is lack of consent, coercion, or simply an imbalance of power or knowledge in the relationship. Childhood sibling–sibling incest is also considered to be widespread but rarely reported. The most commonly reported form of abusive sibling incest is abuse between an older brother and a younger brother or sister.<ref name=Turner />

According to a study by Floyd Martinson, 10–15% of college students reported childhood sexual experiences with a brother or sister, mostly fondling of genitals rather than sexual intercourse. Of those, 30% reported negative reactions and 30% reported positive reactions; 25% of the reported experiences involved coercion and there was a correlation of coercion with the negative responses.<ref>[http://www.ethicaltreatment.org/research.htm CHILD AND ADOLESCENT SEXUALITY]</ref>  A 2006 study showed a large portion of adults who experienced sibling incest have distorted or disturbed beliefs both about their own experience and the subject of sexual abuse in general.<ref name="Carlson "> Bonnie E. Carlson, PhD (December, 2006). "[http://www.ncbi.nlm.nih.gov/pubmed/17200052?dopt=Abstract Sibling Incest: Reports from Forty-One Survivors]", ''Journal of Child Sexual Abuse'': Volume 15, Issue 4, December 2006, Pages 19–34.</ref> An observational study in 1993 found that 16 percent of the 930 adult women interviewed reported that they had been sexually abused by a sibling before they were 18 years old.<ref name=leder></ref>  

Sibling 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 and thereby express their feelings of hurt and rage.<ref name=leder /> 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.<ref name=rudd></ref>  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.<ref name=rudd /><ref name=cyr></ref>

===Between consenting adults===
Incest between consenting adults is sexual behavior between adult, blood relatives (which can include parents and adult offspring, siblings, cousins, etc.) that is not coerced or forced in any way.<ref name="guardian2002"></ref> While incest between consenting adults has not been widely reported in the past, the internet has shown that this behavior does take place, possibly more often than many people realize.<ref name="guardian2002" /> Internet chatrooms and topical websites exist that provide support for incestuous couples.<ref name="guardian2002" />

Proponents of incest between consenting adults draw clear boundaries between the behavior of consenting adults and rape, child molestation, and abuse.<ref name="guardian2002" /> According to one incest participant who was interviewed for an article in ''The Guardian''

<blockquote>"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."<ref name="guardian2002"/></blockquote>

''The Guardian'' article also states:

<blockquote>Voices in Action, a US support group for victims of incest, vehemently rejects these arguments: "These teens have been brainwashed into believing this behaviour is natural; it is not ... Sexual abuse is learned behaviour." But some political thinkers are prepared to support the distinction between abuse and consenting relationships. "<ref name="guardian2002"/></blockquote> 

In ''Slate Magazine'', William Saletan drew a legal connection between gay sex and incest between consenting adults.<ref name="slate2003"></ref> As he described in his article, in 2003, U.S. Senator Rick Santorum publicly derided the theory of the Supreme Court ruling to allow private consensual sex in the home (primarily as a gay rights move). 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."<ref name="slate2003" /> 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.<ref name="slate2003" />

==== Between adult siblings ====
The most public case of consensual adult sibling incest in recent years is the case of a couple from Leipzig, Germany.<ref name="spiegel" /> The couple became intimately close after the death of their mother and in 2001, had their first child together (they have a total of four). 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.<ref name="spiegel" /> For all intents and purposes, the couple are happy together and incest between consenting adults in general, as described in a ''Der Spiegel'' article about them, is a victimless crime.<ref name="spiegel" />

==== Between adult cousins ====

In most countries, marriage between cousins is legal, though some religious restrictions exist - for example marriage between first cousins is forbidden by the Orthodox Church, and requires Diocesan approval in the Roman Catholic Church.<ref>A H Bittles [http://writ.news.findlaw.com/grossman/20020408.html The bases of Western attitudes to consanguineous marriage]</ref> The United States, uniquely, prohibits such marriages in many states as incestuous. <ref>Joanna Grossman, [http://writ.news.findlaw.com/grossman/20020408.html Should the law be kinder to kissin' cousins?]</ref>

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.

==== Incest defined through marriage ====
Some cultures include relatives by marriage in incest prohibitions; these relationships are called affinity rather than 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. In medieval Europe, standing as a godparent to a child also created a bond of affinity.  But in other societies, a deceased spouse's brother or sister was considered the ideal person to marry.  The Hebrew Bible even forbids a man to marry his brother's widow, but has the exception of if his brother died childless, in which case a man is required to marry his brother's widow so as to "raise up seed to him."