Incest: Difference between revisions

 

'''Incest''' ({{IPAc-en|ˈ|ɪ|n|s|ɛ|s|t|}} {{respell|IN|sest}}) is [[Human sexual activity|sexual activity]] between [[kinship|close relatives]], such as a [[sibling]] or [[parent]].<ref>{{cite book |last1=Harkins |first1=Gillian |title=The International Encyclopedia of Human Sexuality |chapter=Incest |date=2015 |pages=583–625 |doi=10.1002/9781118896877.wbiehs231|isbn=978-1-4051-9006-0 }}</ref><ref>{{cite web|title=Incest|publisher=[[Oxford University Press]]|year=2013|access-date=27 August 2013|url=http://oxforddictionaries.com/us/definition/american_english/incest|archive-url=https://web.archive.org/web/20130626012345/http://oxforddictionaries.com/us/definition/american_english/incest|archive-date=26 June 2013}}</ref><ref>{{cite web|title=Incest|publisher=[[Rape, Abuse & Incest National Network]] (RAINN)|year=2009|access-date=27 August 2013|url=http://www.rainn.org/get-information/types-of-sexual-assault/incest}}</ref> This typically includes any kind of sexual activity between people in [[consanguinity]] (blood relations), and sometimes those related by [[lineage (anthropology)|lineage]]. It is condemned and considered immoral in many societies. It can lead to an increased risk of [[genetic disorders]] in children in case of pregnancy from incestuous sex.

The [[incest taboo]] is one of the most widespread of all cultural [[taboo]]s, both in present and in past societies.<ref name="Bittles">{{Cite book |url=https://books.google.com/books?id=t6CsCXXE8skC&pg=PA178 |title=Consanguinity in Context |last=Bittles |first=Alan Holland |publisher=[[Cambridge University Press]] |year=2012 |isbn=978-0-521-78186-2 |pages=178–187 |access-date=27 August 2013}}</ref> Most modern societies have [[laws regarding incest]] or social restrictions on closely consanguineous marriages.<ref name="Bittles"/> In societies where it is illegal, consensual adult incest is seen by some as a [[victimless crime]].<ref name="spiegel">{{cite magazine |last=Hipp |first=Dietmar |url=http://www.spiegel.de/international/germany/0,1518,540831,00.html |title=German High Court Takes a Look at Incest |date=11 March 2008 |magazine=Der Spiegel |access-date=12 April 2008}}</ref><ref name= Wolf169>{{cite book |title=Inbreeding, Incest, and the Incest Taboo: The State of Knowledge at the Turn of the Century |author1-link=Arthur P. Wolf |first1=Arthur P. |last1=Wolf |first2=William H. |last2=Durham |author2-link=William H. Durham |year=2004 |publisher=Stanford University Press |page=169 |url=https://books.google.com/books?id=OW1nuQxcIQgC&pg=PA169 |isbn=978-0-8047-5141-4}}</ref> Some cultures extend the incest taboo to relatives with no consanguinity, such as [[Milk kinship|milk-siblings]], stepsiblings, and adoptive siblings, albeit sometimes with less intensity.<ref>Encyclopedia of Love in World Religions – Volume 1 – Page 321, Yudit Kornberg Greenberg – 2008</ref><ref>Language and Social Relations – Page 379, Asif Agha – 2007.</ref> Third-degree relatives (such as half-aunt, half-nephew, first cousin) on average have 12.5% common genetic heritage, and sexual relations between them are viewed differently in various cultures, from being discouraged to being socially acceptable.<ref>The Encyclopedia of Genetic Disorders and Birth Defects – Page 101, James Wynbrandt, Mark D. Ludman – 2009.</ref> Children of incestuous relationships have been regarded as [[Legitimacy (family law)|illegitimate]],{{Where|date=February 2024}} and are still so regarded in some societies today. In most cases, the parents did not have the option to marry to remove that status, as incestuous marriages were, and are, normally also prohibited.

A common justification for prohibiting incest is avoiding [[inbreeding]], a collection of [[inbreeding#Genetic disorders|genetic disorders]] suffered by the children of parents with a close [[Coefficient of relationship|genetic relationship]].<ref name=WolfDurham2005 /> Such children are at greater risk of congenital disorders, developmental and physical disability, and death; that risk is proportional to their parents' [[coefficient of relationship]], a measure of how closely the parents are related genetically.<ref name=WolfDurham2005>{{cite book |title=Inbreeding, Incest, and the Incest Taboo: The State of Knowledge at the Turn of the Century |first1=Arthur P. |last1=Wolf |first2=William H. |last2=Durham |year=2004 |publisher=Stanford University Press |page=3 |url=https://books.google.com/books?id=OW1nuQxcIQgC&pg=PA3 |isbn=978-0-8047-5141-4}}</ref><ref name=Afzal>{{cite journal |last1=Fareed |first1=M |last2=Afzal |first2=M |year=2014 |title=Estimating the inbreeding depression on cognitive behavior: A population based study of child cohort |journal=PLOS ONE |volume=9 |issue=10 |article-number=e109585 |doi=10.1371/journal.pone.0109585 |pmid=25313490 |pmc=4196914|bibcode=2014PLoSO...9j9585F |doi-access=free  |issn = 1932-6203}}</ref> However, cultural anthropologists have noted that [[inbreeding avoidance]] cannot form the sole basis for the incest taboo because the boundaries of the incest prohibition vary widely between cultures and not necessarily in ways that maximize the avoidance of inbreeding.<ref name=WolfDurham2005 /><ref>{{cite journal | last1 = Schneider | first1 = D. M. | year = 1976 | title = The meaning of incest | journal = The Journal of the Polynesian Society | volume = 85 | issue = 2| pages = 149–169 }}</ref><ref>{{cite journal | last1 = White | first1 = L. A. | year = 1948 | title = The definition and prohibition of incest | journal = American Anthropologist | volume = 50 | issue = 3| pages = 416–435 | doi = 10.1525/aa.1948.50.3.02a00020 | pmid = 18874938 }}</ref><ref>{{cite journal | last1 = Schechner | first1 = R | year = 1971 | title = Incest and culture: A reflection on Claude Lévi-Strauss | journal = Psychoanalytic Review | volume = 58 | issue = 4| pages = 563–72 | pmid = 4948055 }}</ref>

In some societies, such as those of [[Ancient Egypt]], brother-sister, father-daughter, mother-son, cousin-cousin, aunt-nephew, uncle-niece, and other combinations of relations within a [[royal family]] were married as a means of perpetuating the royal lineage, or echoing the practices in their creation myths, and were considered normal.<ref>[[Maurice Godelier]], Métamorphoses de la parenté, 2004</ref><ref>{{cite web |url=http://newleftreview.org/?view=2592 |title=New Left Review – Jack Goody: The Labyrinth of Kinship |access-date=24 July 2007}}</ref><ref>{{cite journal |title=Ancient Egyptian Creation Myths and Brother-sister Marriage in the 18th Dynasty and the 19th Dynasty |journal=Studies in Mythology |volume=12 |year=2025 |pages=264–280 |url=http://www.sass.cn/128001/79422.aspx |last1=LAU |first1=Yin Pak Andrew |archive-date=11 October 2025 |access-date=15 September 2025 |archive-url=https://web.archive.org/web/20251011132357/http://www.sass.cn/128001/79422.aspx |url-status=dead }}</ref> Some societies have different views about what constitutes [[illegal or immoral incest]]. For example, in [[Samoa]], a man was permitted to marry his older sister, but not his younger sister.<ref>{{cite book |last= Lechte|first= John|date= 24 February 2003|title= Key Contemporary Concepts From Abjection to Zeno's Paradox|publisher= SAGE Publications|page= 82|isbn= 978-0-7619-6534-3}}</ref> However, sexual relations with a first-degree relative (meaning a parent, sibling, or child) were almost universally forbidden in connection with multiple cases of disorders and organ failures.<ref>''The Tapestry of Culture: An Introduction to Cultural Anthropology'', Ninth Ed., Abraham Rosman, Paula G. Rubel, Maxine Weisgrau, 2009, AltaMira Press, p. 101</ref>

The English word ''[[wikt:incest|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 (preserved throughout the Middle English period)<ref>[[OED]] [[Ancrene Riwle]] (c. 1225) has ''Incest‥is bituȝe sibbe fleschliche'', where either the generic or the narrow sense may be intended. See also [http://www.etymonline.com/index.php?search=incest&searchmode=none inetymonline.comest]</ref> and in the narrow modern sense. The derived adjective ''incestuous'' appears in the 16th century.<ref>''Oxford Concise Dictionary of Etymology'', T. F. Hoad (ed.) (1996), p. 232</ref> Before the Latin term came in, incest was known in [[Old English]] as ''sib-leger'' (from ''sibb'' 'kinship' + ''leger'' 'to lie') or ''mǣġhǣmed'' (from ''mǣġ'' 'kin, parent' + ''hǣmed'' 'sexual intercourse') but in time, both words fell out of use. Terms like ''incester''<ref>{{cite book |last1=Wollert |first1=R |title=An analysis of the argument that clinicians under-predict sexual violence in civil commitment cases |date=2001 |pages=171–184 |url=http://www.richardwollert.com/BSLarticle.html |quote=His first criterion was that follow-up research on rapists and extrafamilial molesters should be studied while research on incesters and intrafamilial molesters should be screened out. |archive-date=26 April 2016 |access-date=4 May 2016 |archive-url=https://web.archive.org/web/20160426042706/http://www.richardwollert.com/BSLarticle.html |url-status=dead }}</ref><ref>{{cite journal |last1=Crowley |first1=Sue |title=Exploring the multiplicity of childhood sexual abuse with a focus on polyincestuous contexts of abuse |journal=Journal of Child Sexual Abuse |date=2002 |volume=10 |issue=4 |publisher=[[Taylor & Francis]] |pages=91–110 |doi=10.1300/J070v10n04_07 |pmid=16221629 |s2cid=10707236 |quote=They also suggested that researchers have created "a false dichotomy" (p. 33) by studying extrafamilial child molesters (eg, those who abuse other families' children) as though they were distinct from intrafamilial child incesters (eg, those who molest children within their own family)}}</ref><ref>{{cite journal |last1=Caputi |first1=Jane |title=Unthinkable fathering: connecting incest and nuclearism |journal=[[Hypatia (journal)|Hypatia]] |volume=9 |issue=2 |date=2009 |publisher=[[Wiley Online Library]] |pages=102–122 |doi=10.1111/j.1527-2001.1994.tb00435.x |jstor=3810172|s2cid=145443764}}</ref> and ''incestual''<ref>{{cite book |last1=L Conyers |first1=James |title=Black Cultures and Race Relations |date=2002 |publisher=[[Rowman & Littlefield]] |isbn=978-0-8304-1574-8 |page=115 |url=https://books.google.com/books?id=l_dukyNja_YC&q=%22%22&pg=PA115}}</ref><ref>{{cite book |author=University of California |title=American Journal of Psychiatry |date=1945 |page=425 |edition=Volume 101 |quote=Psychoanalytic interpretations of some of the elements of incestuous reactions and a classification of incestuals are proposed.}}</ref> have been used to describe those interested or involved in sexual relations with relatives among humans, while ''inbreeder'' has been used in relation to similar behavior among non-human organisms.<ref>{{cite book |last1=Charlesworth |first1=Deborah |title=Introduction to Plant Population Biology |date=2009 |publisher=[[John Wiley & Sons]] |page=80}}</ref>

Several of the Egyptian [[king]]s married their sisters and had several children with them to continue the royal bloodline. For example, [[Tutankhamun]] married his half-sister [[Ankhesenamun]], and was himself the child of an incestuous union between [[Akhenaten]] and an unidentified sister-wife. Several scholars, such as Frier et al., state that sibling marriages were widespread among all classes in Egypt during the Graeco-Roman period. Numerous [[papyrus|papyri]] and the Roman census declarations attest to many husbands and wives being brother and sister, of the same father and mother.<ref>{{cite book |last=Lewis |first=N. |title=Life in Egypt under Roman Rule |isbn=978-0-19-814848-7 |publisher=[[Oxford University Press|Clarendon Press]] |year=1983 |url-access=registration |url=https://archive.org/details/lifeinegyptunder0000lewi }}</ref><ref>{{cite book |last1=Frier |first1=Bruce W. |last2=Bagnall |first2=Roger S. |author2-link=Roger S. Bagnall |title=The Demography of Roman Egypt |publisher=[[Cambridge University Press]] |location=Cambridge, UK |year=1994 |isbn=978-0-521-46123-8}}</ref><ref>{{cite journal |last=Shaw |first=B. D. |title=Explaining Incest: Brother-Sister Marriage in Graeco-Roman Egypt |journal=Man |series=New Series |volume=27 |issue=2 |year=1992 |pages=267–299 |jstor=2804054 |doi=10.2307/2804054}}</ref><ref>{{cite journal |last=Hopkins |first=Keith |author-link=Keith Hopkins |year=1980 |title=Brother-Sister Marriage in Roman Egypt |url=http://humweb.ucsc.edu/jklynn/ancientwomen/HopkinsBrotherSisterMarriage.pdf |journal=Comparative Studies in Society and History |volume=22 |pages=303–354 |doi=10.1017/S0010417500009385 |issue=3 |s2cid=143698328 |access-date=21 July 2013 |archive-date=3 March 2016 |archive-url=https://web.archive.org/web/20160303180202/http://humweb.ucsc.edu/jklynn/ancientwomen/HopkinsBrotherSisterMarriage.pdf }}</ref> However, it has also been argued that the available evidence does not support the view that such relations were common.<ref>Walter Scheidel. 2004. "Ancient Egyptian Sibling Marriage and the Westermarck Effect", in ''Inbreeding, Incest, and the Incest Taboo: the state of knowledge at the turn of the century'' Arthur Wolf and William Durham (eds) Stanford University Press. pp. 93–108</ref><ref>{{cite journal | last1 = Huebner | first1 = Sabine R | author-link = Sabine R. Huebner | year = 2007 | title = 'Brother-Sister' Marriage in Roman Egypt: a Curiosity of Humankind or a Widespread Family Strategy?. | journal = The Journal of Roman Studies | volume = 97 | pages = 21–49 | doi = 10.3815/000000007784016070 }}</ref><ref>Huebner, Sabine R. The family in Roman Egypt: a comparative approach to intergenerational solidarity and conflict. Cambridge University Press, 2013.</ref>

The most famous of these relationships were in the [[Ptolemaic dynasty|Ptolemaic royal family]]; [[Cleopatra VII]] was married to two of her younger brothers, [[Ptolemy XIII]] and [[Ptolemy XIV]], whilst her mother and father, [[Cleopatra V of Egypt|Cleopatra V]] and [[Ptolemy XII]], were also brother and sister. [[Arsinoe II]] and her younger brother [[Ptolemy II|Ptolemy II Philadelphus]] were the first in the family to participate in a full-sibling marriage, a departure from custom.<ref name="Familiarity Breeds: Incest and the">{{cite journal |last1=Ager |first1=Sheila L. |title=Familiarity Breeds: Incest and the Ptolemaic Dynasty |journal=The Journal of Hellenic Studies |date=2005 |volume=125 |pages=1–34 |doi=10.1017/S0075426900007084 |jstor=30033343 |pmid=19681234  |issn=0075-4269}}</ref> A union between full siblings was not the norm in Greek and Macedonian tradition, and prohibited by the laws of at least some cities.<ref name="Familiarity Breeds: Incest and the"/><ref name="The Routledge Companion to Women and Monarchy in the Ancient Mediterranean World">{{cite book |author=<!--Staff writer(s); no by-line.--> |title= The Routledge Companion to Women and Monarchy in the Ancient Mediterranean World|publisher= Taylor & Francis|date= 9 November 2020|isbn= 978-0-429-78398-2}}</ref>

The earliest Biblical reference to possible incest involves Cain. It was cited that he knew his wife and she conceived and bore Enoch.<ref name=":1">{{Cite book|title=Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices|last=Aggrawal|first=Anil|publisher=CRC Press|year=2009|isbn=978-1-4200-4308-2|location=Boca Raton, FL|page=320}}</ref> A literalist reading of this passage indicates that, during this period, there was no other woman except Eve, or there was an unnamed sister, in which case Cain had an incestuous relationship with his mother or his sister.<ref name=":1" /> According to the [[Book of Jubilees]], [[Cain]] married his sister [[Awan (religious figure)|Awan]].<ref>Cain and Abel in Text and Tradition: Jewish and Christian Interpretations of the First Sibling Rivalry, John Byron – 2011, page 27</ref><ref>The Empowerment of Women in the Book of Jubilees – Page 17, Betsy Halpern Amaru – 1999</ref> Later, in Genesis 20<ref>''Hebrew-English Bible,'' {{bibleverse||Genesis|20:12|HE}}</ref> of the [[Hebrew Bible]], the [[Patriarch]] [[Abraham]] married his half-sister [[Sarah]].{{sfn|Ska|2009|pp=26–31}} Other references include the passage in 2 Samuel 13 where [[Amnon]], King [[David]]'s son, rapes his half-sister [[Tamar (2 Samuel)|Tamar]].<ref>''Bible'', {{bibleverse|2|Samuel|13|NIV}}</ref> According to [[Michael D. Coogan]], it would have been perfectly all right for Amnon to have married her, the Bible being inconsistent about prohibiting incest.<ref>{{cite book|last=Coogan|first=Michael|title=God and Sex. What the Bible Really Says|url=https://archive.org/details/godsexwhatbi00coog|url-access=registration|quote=god and sex.|access-date=5 May 2011|edition=1st|year=2010|publisher=Twelve. Hachette Book Group|location=New York, Boston|isbn=978-0-446-54525-9|oclc=505927356|pages=[https://archive.org/details/godsexwhatbi00coog/page/112 112]–113}}</ref>

Moses was also born of an incestuous marriage. Exodus 6<ref>''Hebrew-English Bible'', {{bibleverse||Exodus|6:20|HE}}</ref> details how his father, [[Amram]], was the nephew of his mother, [[Jochebed]].<ref name=":1" /> An account noted that the incestuous relations did not suffer the fate of childlessness, which was the punishment for such couples in Levitical law.<ref name=":2">{{Cite book|title=Sex, Marriage, and Family in John Calvin's Geneva: Courtship, Engagement, and Marriage|last1=John|first1=Witte Jr.|last2=Kingdon|first2=Robert|publisher=William B. Eerdmans Publishing Company|year=2005|isbn=978-0-8028-4803-1|location=Grand Rapids|page=321}}</ref> It stated, however, that the incest exposed Moses "to the peril of wild beasts, of the weather, of the water, and more."<ref name=":2" />

Marriages between younger brothers and their older sisters were common among the early [[Udege people]].<ref>{{cite book |last= Deusen|first= Kira|date= 2 February 2011|title= Flying Tiger: Women Shamans and Storytellers of the Amur|publisher= McGill Queen's Press|page= 25|isbn= 978-0-7735-2155-1}}</ref>

Sex between an adult family member and a child is a form of child sexual abuse,<ref>{{Cite journal |last=Fridell |first=Lorie A. |title=Decision-making of the District Attorney: diverting or prosecuting intrafamilial child sexual abuse offenders |journal=[[Criminal Justice Policy Review]] |volume=4 |issue=3 |pages=249–267 |doi=10.1177/088740349000400304 |date=October 1990 |s2cid=145654768 }}</ref> also known as '''child incestuous abuse''',<ref>{{cite web |last=Trusiani|first=Jessica|title=Working with Survivors of Child Incestuous Abuse |website=Rutgers School of Social Work |url=http://socialwork.rutgers.edu/Libraries/VAWC/Trusiani_presentation.sflb.ashx|archive-url=https://web.archive.org/web/20141101063712/http://socialwork.rutgers.edu/Libraries/VAWC/Trusiani_presentation.sflb.ashx|archive-date=1 November 2014}}</ref> and for many years has been the most reported form of incest. Father–daughter and stepfather–stepdaughter sexual abuse are the most commonly reported forms of adult–child incest, with most of the remaining involving a mother or stepmother.<ref name=Turner>{{cite book |title=Encyclopedia of Relationships Across the Lifespan |last=Turner |first=Jeffrey S. |year=1996 |publisher=Greenwood Publishing Group |page=[https://archive.org/details/encyclopediaofre0000turn/page/92 92] |isbn=978-0-313-29576-8 |url=https://archive.org/details/encyclopediaofre0000turn/page/92 }}</ref> Many studies found that stepfathers tend to be far more likely than biological fathers to engage in this form of incest. One study of adult women in San Francisco estimated that 17% of women were abused by stepfathers and 2% were abused by biological fathers.<ref>{{cite book |last=Kinnear |first=Karen L. |title=Childhood Sexual Abuse: A Reference Handbook |page=8}}</ref> Father–son incest is reported less often, but it is not known how close the frequency is to heterosexual incest because it is probably more under-reported.<ref>{{Cite journal |doi=10.1007/BF00754448|title=Father-son incest: A review and analysis of reported incidents|journal=Clinical Social Work Journal|volume=16|issue=2|pages=165–179|year=1988|last1=Williams|first1=Mark|s2cid=144258944}}</ref><ref>{{Cite journal |doi=10.1176/ajp.135.7.835|pmid=665796|title=Father-son incest: Underreported psychiatric problem?|journal=American Journal of Psychiatry|volume=135|issue=7|pages=835–838|year=1978|hdl=1811/51174|last1=Dixon|first1=K. N.|last2=Arnold|first2=L. E.|last3=Calestro|first3=K.|citeseerx=10.1.1.1018.8536}}</ref><ref>{{cite book |title=Don't Tell: The Sexual Abuse of Boys |first=Michel |last=Dorais |translator=Isabel Denholm Meyer |year=2002 |page=24 |publisher=McGill-Queen's Press |isbn=978-0-7735-2261-9}}</ref><ref>{{cite book |title=Healing the Incest Wound: Adult Survivors in Therapy |first=Christine A. |last=Courtois |year=1988 |publisher=W. W. Norton & Company |isbn=978-0-393-31356-7}}</ref> The prevalence of incest between parents and their children is difficult to estimate due to the coercive silencing of victims.  

{{blockquote|1=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 stepfathers, and another 16% are raped by other relatives.<ref>{{cite web|url=http://www.ncvc.org/ncvc/main.aspx?dbName=DocumentViewer&DocumentID=32360|title=Incest|work=National Center for Victims of Crime and Crime Victims Research and Treatment Center|year=1992|publisher=National Center for Victims of Crime|access-date=27 March 2008|archive-date=10 August 2020|archive-url=https://web.archive.org/web/20200810214920/http://www.ncvc.org/ncvc/main.aspx?dbName=DocumentViewer&DocumentID=32360}}</ref>}}

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 disorder]]s, including [[Clinical depression|depression]], [[anxiety disorder]]s, [[Phobia|phobic avoidance reactions]], [[somatoform disorder]], [[substance abuse]], [[borderline personality disorder]], and [[complex post-traumatic stress disorder]].<ref name="Courtois" /><ref>{{cite book |last2=Barrett |first2=Mary Jo |title=Systemic Treatment of Incest: A Therapeutic Handbook |last1=Trepper |first1=Terry S. |publisher=Psychology Press |year=1989 |isbn=978-0-87630-560-7}}</ref><ref>{{cite book |title=Incest-Related Syndromes of Adult Psychopathology |first=Richard P. |last=Kluft |year=1990 |publisher=American Psychiatric Pub, Inc. |pages=83, 89 |isbn=978-0-88048-160-1}}</ref>

Proponents of incest between consenting adults draw clear boundaries between the behavior of consenting adults on one hand and rape, child molestation, and abusive incest on the other.<ref name="guardian2002">{{cite news |last=Hari |first=Johann |date=9 January 2002 |title=Forbidden love |url=https://www.theguardian.com/Archive/Article/0,4273,4331603,00.html |access-date=11 April 2008 |newspaper=[[The Guardian]] |issn=0261-3077}}</ref> However, even consensual relationships such as these are still legally classified as incest<ref>{{cite book |author=Roffee |first=James |title=Rape Justice: Beyond the Criminal Law |year=2015 |isbn=978-1-137-47615-9 |pages=72–91 |chapter=When Yes Actually Means Yes |doi=10.1057/9781137476159_5}}</ref> and criminalized in many jurisdictions (although there are [[Legality of incest|certain exceptions]]). James Roffee, a senior lecturer in criminology at [[Monash University]] and former worker on legal responses to familial sexual activity in England and Wales, and Scotland<ref>{{cite web|url=http://monash.edu/research/explore/en/persons/james-roffee(896c15d7-6f28-4bf0-8a0f-b7d6ff1553e0).html|title=Dr James Roffee|publisher=Monash university|access-date=22 May 2017|archive-url=https://web.archive.org/web/20170204003059/http://monash.edu/research/explore/en/persons/james-roffee%28896c15d7-6f28-4bf0-8a0f-b7d6ff1553e0%29.html|archive-date=4 February 2017}}</ref> discussed how the [[European Convention on Human Rights]] deems all familial sexual acts to be criminal, even if all parties give their full consent and are knowledgeable to all possible consequences.<ref>{{cite journal|doi=10.1093/hrlr/ngu023|title=No Consensus on Incest? Criminalisation and Compatibility with the European Convention on Human Rights|journal=Human Rights Law Review|volume=14|issue=3|pages=541–572|year=2014|last1=Roffee|first1=J. A.}}</ref> He also argues that the use of particular language tools in the legislation manipulates the reader to deem all familial sexual activities as immoral and criminal, even if all parties are consenting adults.<ref>{{cite journal |author=Roffee |first=J.A. |year=2014 |title=Synthetic Necessary Truth Behind New Labour's Criminalisation of Incest |journal=Social & Legal Studies |volume=23 |pages=113–130 |doi=10.1177/0964663913502068 |s2cid=145292798}}</ref>

Consensual sex between individuals aged 18 and older is always lawful in the Netherlands and Belgium, even among closely related family members. Sexual acts between an adult family member and a minor are illegal, though they are classified not as incest but as abuse of the authority such an adult has over a minor, comparable to that of a teacher, coach, or priest.<ref>{{cite web|url=http://www.elfri.be/incest-strafbaar |title=is incest strafbaar ? &#124; Goede raad is goud waard – Advocatenkantoor Elfri De Neve |publisher=Elfri.be |date=15 July 2009 |access-date=30 July 2013|language=nl}}</ref> In [[Florida]], consensual adult sexual intercourse with someone known to be one's aunt, uncle, niece, or nephew constitutes a felony of the third degree.<ref>Criminal Law – Page 200, John M. Scheb – 2008</ref> Other states also commonly prohibit marriages between such kin.<ref>Family Law in the USA – Page 207, Lynn Dennis Wardle, Laurence C. Nolan – 2011</ref> The legality of sex with a half-aunt or half-uncle varies state by state.<ref>The Encyclopedia of Genetic Disorders and Birth Defects – Page 101, James Wynbrandt, Mark D. Ludman – 2010</ref> In the United Kingdom, incest includes only sexual intercourse with a parent, grandparent, child, or sibling,<ref>{{cite web|title=Incest by a man.|url=http://www.legislation.gov.uk/ukpga/Eliz2/4-5/69/part/I/crossheading/incest|work=Sexual Offences Act 1956|publisher=National Archives UK|access-date=28 March 2014}}</ref> but the more recently introduced offense of "sex with an adult relative" extends as far as half-siblings, uncles, aunts, nephews, and nieces.<ref name=ref1>{{cite web|title=Sexual Offences Act 2003|url=http://www.legislation.gov.uk/ukpga/2003/42/section/64|work=legislation.gov.uk|publisher=The National Archives of United Kingdom|access-date=28 March 2014}}</ref> However, the term 'incest' remains widely used in popular culture to describe any form of sexual activity with a relative. In Canada, marriage between uncles and nieces and between aunts and nephews is illegal.{{Citation needed|date=April 2025}}

In some non-Western societies, marriages between close biological relatives account for 20{{ndash}}60% of all marriages.<ref>{{cite web|url=https://www.larasig.com/node/2020|title=Consanguinity Fact Sheet – Debunking Common Myths|access-date=23 December 2017|archive-url=https://web.archive.org/web/20171223160732/https://www.larasig.com/node/2020|archive-date=23 December 2017}}</ref><ref>{{cite book|url=https://books.google.com/books?id=t2XgDgAAQBAJ&q=20+to+60+%25+of+all+marriages+between+close+biological+relatives&pg=PT282|title=Family Law: Theoretical, Comparative, and Social Science Perspectives|first=James|last=Dwyer|date=9 December 2014|publisher=Wolters Kluwer Law & Business|via=Google Books|isbn=978-1-4548-3155-6}}</ref><ref>"In some parts of the world 20–60% of all marriages are between close biological relatives (Bittles, 1998)"

There are some cultures in Asia which stigmatize cousin marriage, in some instances even marriages between second cousins or more remotely related people. This is notably true in the culture of [[Korea]]. In South Korea, before 1997, two people with the same last name and clan were prohibited from marrying. 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]]). [[Hmong people|Hmong]] culture prohibits the marriage of anyone with the same last name{{nbsp}}{{ndash}} to do so would result in being shunned by the entire community, and they are usually stripped of their last name.<ref>{{Cite book|url=https://books.google.com/books?id=kgaGCwAAQBAJ&q=Hmong+culture+prohibits+the+marriage+of+anyone+with+the+same+last+name&pg=PA192|title=Hmong Refugees in the New World: Culture, Community and Opportunity|last=Vang|first=Christopher Thao|date=16 May 2016|publisher=McFarland|isbn=978-1-4766-2262-0}}</ref>

In Islamic law, marriage among close blood relations like parents, stepparents, parents in-law, siblings, stepsiblings, the children of siblings, aunts, and uncles is forbidden, while first or second cousins may marry.<ref name="Tucker_IslamicLaw">{{cite book |last=Tucker |first=Judith E. |title=Women, Family, and Gender in Islamic Law |publisher=Cambridge University Press |year=2008 |isbn=978-0521537476 |pages=41–42}}</ref> Marrying the widow of a brother or the sister of a deceased or divorced wife is also allowed.<ref name="Tucker_IslamicLaw" />

The closer the relationship between two persons, the higher the zygosity, and thus the more severe the biological costs of inbreeding. This fact probably explains why inbreeding between close relatives, such as siblings, is less common than inbreeding between cousins.<ref>{{cite journal |last1=Antfolk |first1=Jan |last2=Lieberman |first2=Debra |last3=Santtila |first3=Pekka |title=Fitness Costs Predict Inbreeding Aversion Irrespective of Self-Involvement: Support for Hypotheses Derived from Evolutionary Theory |journal=PLOS ONE |volume=7 |issue=11 |doi=10.1371/journal.pone.0050613 |article-number=e50613 |pmid=23209792 |pmc=3509093|year=2012 |bibcode=2012PLoSO...750613A |doi-access=free }}</ref>

Laws regarding sexual activity between close relatives vary considerably between jurisdictions, and depend on the type of sexual activity and the nature of the family relationship of the parties involved, as well as the age and sex of the parties. Prohibition of incest laws may extend to restrictions on marriage rights, which also vary between jurisdictions. Most jurisdictions prohibit parent{{ndash}}child and sibling marriages, while others also prohibit first-cousin and uncle{{ndash}}niece and aunt{{ndash}}nephew marriages. In most places, incest is illegal, regardless of the ages of the two partners. In other countries, incestuous relationships between consenting adults (with the age varying by location) are permitted, including in the [[Netherlands]], [[France]], [[Slovenia]], and [[Spain]]. [[Sweden]] is the only country that allows marriage between half-siblings, and they must seek government counseling before getting to the marriage.<ref>[http://news.bbc.co.uk/1/hi/6424337.stm Incest: an age-old taboo]. BBC. 12 March 2007. retrieved 22 January 2011</ref>

While the legality of consensual incest depends on the country which you live in, sexual assault committed against a close term relative is seen as a very serious crime in most countries. In some legal systems, the fact of a perpetrator being a close relative to the victim constitutes an [[aggravating circumstance]] in the case of any kinds of sexual crimes such as [[rape]] and [[child sexual abuse|sexual conduct with a minor]]{{nbsp}}– this is the case in [[Romania]].<ref>See Articles 218–221 of the [[Penal Code of Romania#The Penal Code of 2014|Romanian Penal Code]] [http://www.avocatura.com/ll491-noul-cod-penal.html] {{Webarchive|url=https://web.archive.org/web/20150517054948/http://www.avocatura.com/ll491-noul-cod-penal.html|date=17 May 2015}}</ref>

 

Jewish views on incest is mixed, with some scholars finding support in modern times only for the case of Jewish survival and genetic purity/preservation. The first religious resource found that prohibits incest, is the Torah, in book of Leviticus, chapter 18,<ref>''Hebrew-English Bible'', {{bibleverse||Leviticus|18|HE}}</ref> "the children of Israel"{{nbsp}}{{ndash}} Israelite men and women alike{{nbsp}}{{ndash}} are forbidden from sexual relations between people who are "near of kin" (verse 6), who are defined as:

* Aunts and nephews, uncles and nieces, etc. (verses 12–14).<ref>Also see the [[Central Conference of American Rabbis]]' [https://ccarnet.org/responsa/142-marriage-mothers-sister-or-half-sister-aunt-or/ Responsum 142].</ref> Relationships between these are the second kind of relationships that are particularly singled out for a curse in [http://www.mechon-mamre.org/e/et/et0527.htm Deuteronomy 27], and the explicit examples of children-in-law and mothers-in-law (verse 23) serve to remind the Israelites that the parents-in-law are also (or at least should also be) the children-in-law's aunts and uncles:<ref>{{Cite web|url=https://www.mechon-mamre.org/e/et/et0436.htm|title=Numbers 36 / Hebrew Bible in English / Mechon-Mamre|website=www.mechon-mamre.org|access-date=14 August 2021|archive-date=25 September 2021|archive-url=https://web.archive.org/web/20210925053705/https://www.mechon-mamre.org/e/et/et0436.htm}}</ref>

{{see also|Mahram|Cousin marriage in the Middle East|l2=Cousin marriage in Islam|Criticism of Islam}}

 

* his sister, his half-sister, a woman who has nursed from the same woman as him, and his sister-in-law (wife's sister) while still married. Half relations are as sacred as full relations;<ref name="qref 4:23">{{qref|4|23|c=y}}</ref>

* his daughter, his stepdaughter (if the marriage to her mother was [[consummation|consummated]]), his daughter-in-law.<ref name="qref 4:23" />

* his niece (child of sibling);<ref name="qref 4:23" />

Cousin marriage is discouraged. Historically especially before Islam, in certain regions, [[Cousin marriage in the Middle East|widespread in the Middle East]].<ref>{{cite book |last1=Inhorn |first1=Marcia C. |first2=Wendy |last2=Chavkin |first3=José-Alberto |last3=Navarro |date=2014 |title=Globalized Fatherhood |location=New York City |publisher=Berghahn Books |page=245 |isbn=978-1-78238-438-0 }}</ref>

Although Islam does not specifically cite punishments for cousin marriage, there are [[hadith]]s attributed to Muhammad calling for distance from the marriage of relatives.<ref>{{cite web|author1=Shaykh Faraz A. Khan|title=Did the Prophet (Peace Be Upon Him) Discourage Marrying Cousins? – SeekersHub Answers|url=http://seekershub.org/ans-blog/2011/10/07/did-the-prophet-peace-be-upon-him-discourage-marrying-cousins/|website=SeekersHub Answers|access-date=12 August 2017|date=7 October 2011|archive-date=2 May 2019|archive-url=https://web.archive.org/web/20190502215209/http://seekershub.org/ans-blog/2011/10/07/did-the-prophet-peace-be-upon-him-discourage-marrying-cousins/}}</ref><ref>{{cite web|author1=Saleem Ahmed, Ph.D|title=Cousin Marriage Among Muslims|url=http://muslimcouncilofamerica.org/cousin-marriage-among-muslims/|website=Muslim Council of America Foundation|access-date=12 August 2017|archive-date=12 August 2017|archive-url=https://web.archive.org/web/20170812173119/http://muslimcouncilofamerica.org/cousin-marriage-among-muslims/|url-status=usurped}}</ref>

 

In [[Ancient Persia]], incest between cousins is a blessed virtue, although, in some sources, incest is believed to be related to that of parent{{ndash}}child or brother{{ndash}}sister.<ref name=":0">{{Cite book|url=https://books.google.com/books?id=0qcdrMTprSMC|archive-url=https://web.archive.org/web/20200803085652/https://books.google.com/books?id=0qcdrMTprSMC|archive-date=3 August 2020|title=Sex and Punishment: Four Thousand Years of Judging Desire|last=Berkowitz|first=Eric|date=2012|publisher=Counterpoint Press|isbn=978-1-58243-796-5|pages=21–22}}</ref> Under [[Zoroastrianism]], royalty, clergy, and commoners practiced incest, though the extent in the lattermost class was unknown.<ref name="Skjaervo 2013">{{Cite web|url=http://www.iranicaonline.org/articles/marriage-next-of-kin|title=Marriage II. Next-Of -Kin Marriage In Zoroastrianism|last=Skjaervo|first=Prods Oktor|author-link=Prods Oktor Skjaervo|website=www.iranicaonline.org|publisher=[[Encyclopaedia Iranica]], online edition|date=2013|access-date=20 August 2018}}</ref><ref name=":0" /> This tradition was called [[Xwedodah]]<ref>{{Cite journal|last=Bigwood|first=Joan M.|date=December 2009|title='Incestuous' Marriage in Achaemenid Iran: Myths and Realities|journal=Klio|volume=91|issue=2|pages=311–341|doi=10.1524/klio.2009.0015|s2cid=191672920|issn=0075-6334}}</ref><ref>{{Cite journal|last=Scheidel|first=Walter|date=1 September 1996|title=Brother-sister and parent-child marriage outside royal families in ancient egypt and iran: A challenge to the sociobiological view of incest avoidance?|url=https://www.researchgate.net/publication/223430185|journal=Ethology and Sociobiology|volume=17|issue=5|pages=319–340|doi=10.1016/S0162-3095(96)00074-X}}</ref><ref>{{Cite journal|last=García|first=María Olalla|date=2001|title="Xwedodah": el matrimonio consanguíneo en la Persia Sásanida. Una comparación entre fuentes pahlavíes y greco-latinas|url=https://publicaciones.unirioja.es/ojs/index.php/iberia/article/view/267|journal=Iberia. Revista de la Antigüedad|language=es|volume=4|pages=181–197|issn=1699-6909}}</ref> ({{Langx|ae|Xᵛaētuuadaθa }}).<ref name="Skjaervo 2013"/><ref>{{Cite book|url=https://books.google.com/books?id=cNUEnHU0BPoC&q=xwedodah&pg=PA430|title=Traditions of the Magi: Zoroastrianism in Greek and Latin Literature|last=Jong|first=Albert De|date=1997|publisher=BRILL|isbn=978-90-04-10844-8|pages=430–433}}</ref> The tradition was considered so sacred that the bodily fluids produced by an incestuous couple were thought to have curative powers.<ref name=":0" /> For instance, the [[Vendidad]] advised corpse-bearers to purify themselves with a mixture of the urine of a married incestuous couple.<ref name=":0" /> [[Friedrich Nietzsche]], in his book ''[[The Birth of Tragedy]]'', cited that among Zoroastrians, a wise priest is born only by Xvaetvadatha.<ref>''The Birth of Tragedy'', Friedrich Nietzsche. Anaconda Verlag – 2012.</ref>

==Other animals==

[[File:Fruit flies mating.jpg|thumb|[[Drosophila melanogaster|Common fruit fly]] females prefer to mate with their own brothers over unrelated males.<ref name="fruit-flies">{{cite journal |last1=Loyau |first1=Adeline |last2=Cornuau |first2=Jérémie H. |last3=Clobert |first3=Jean |last4=Danchin |first4=Étienne |date=10 December 2012 |title=Incestuous Sisters: Mate Preference for Brothers over Unrelated Males in Drosophila melanogaster |journal=PLOS ONE |volume=7 |issue=12 |article-number=e51293 |bibcode=2012PLoSO...751293L |doi=10.1371/journal.pone.0051293 |pmc=3519633 |pmid=23251487 |doi-access=free}}</ref>]]

Inbreeding avoidance is rare in non-human animals.<ref>{{Cite journal |last1=de Boer |first1=Raïssa A. |last2=Vega-Trejo |first2=Regina |last3=Kotrschal |first3=Alexander |last4=Fitzpatrick |first4=John L. |date=July 2021 |title=Meta-analytic evidence that animals rarely avoid inbreeding |url=https://www.nature.com/articles/s41559-021-01453-9 |journal=Nature Ecology & Evolution |language=en |volume=5 |issue=7 |pages=949–964 |doi=10.1038/s41559-021-01453-9 |pmid=33941905 |bibcode=2021NatEE...5..949D |s2cid=233718913 |issn=2397-334X|url-access=subscription }}</ref> [[North Carolina State University]] found that [[bed bug]]s, in contrast to most other insects, tolerate inbreeding and are able to genetically withstand its effects quite well.<ref>{{cite web |url=http://www.laboratoryequipment.com/news/2011/12/insect-incest-produces-healthy-offspring |title=Insect Incest Produces Healthy Offspring |date=8 December 2011 |access-date=14 February 2017 |archive-date=16 May 2017 |archive-url=https://web.archive.org/web/20170516080757/http://www.laboratoryequipment.com/news/2011/12/insect-incest-produces-healthy-offspring }}</ref>

* {{cite encyclopedia | article = Women i. In Pre-Islamic Persia | last = Brosius | first = Maria | url = http://www.iranicaonline.org/articles/women-i | encyclopedia = Encyclopaedia Iranica, Vol | location = London et al. | year = 2000 | title = <!-- nope --> | access-date = 2019-09-21 | archive-url = https://web.archive.org/web/20200313213156/http://www.iranicaonline.org/articles/women-i | archive-date = 2020-03-13 }}