# Why is incest so bad? **URL:** \ **Category:** Great Debates\ **Created:** [February 2, 2005, 11:49pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075 "2005-02-02T23:49:57Z")\ **Posts on this page:** 19\ **Page:** 2
**Author:** ![MrFantsyPants](https://avatars.discourse-cdn.com/v4/letter/m/7ba0ec/32.png) [@MrFantsyPants](https://boards.straightdope.com/u/MrFantsyPants)\ **Post date:** [February 3, 2005, 12:09pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/21 "2005-02-03T12:09:02Z")
> [@Domokun](#): > > I can’t help but think two siblings who consented to an insectual relationship must be seriously disturbed in some other way. I keep thinking of the couple in “People under the Stairs” when I read this. So, if two people have a high chance of having unhealthy offspring, is it the government’s role to stop them from marrying and reproducing? I find that to be a very tough question. Ignoring the brother/sister thing, and just thinking “genetically incompatible”, then how do you justify the government getting involved in some cases, but not others (two people with mild sickle-cell, say). Then again, won’t someone think of the (un-concieved) children? As for parents marrying children. I am strictly against this. As someone who ran a business for 12 years in partnership with a parent, I can say that the parent/child relationship does not translate well into an equal relationship. It (IMO) will almost always cause problems. Whether it should be legislated against, I’m not sure, but I do feel this type of marriage is wrong. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [February 3, 2005, 12:15pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/22 "2005-02-03T12:15:06Z")
All I can think of with regard to legalized incest between consenting adults (people over 18) is, damn, that will really cross the wires of your family tree and create some odd tensions at family reunions. Families are screwed up enough without having everybody screwing each other. ---
**Author:** ![Arwin](https://avatars.discourse-cdn.com/v4/letter/a/51bf81/32.png) [@Arwin](https://boards.straightdope.com/u/Arwin)\ **Post date:** [February 3, 2005, 12:15pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/23 "2005-02-03T12:15:58Z")
Everyone interested in this thread should see Old Boy, the Korean Cannes winner (when Tarantino was head of jury). It’s awesome. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [February 3, 2005, 12:21pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/24 "2005-02-03T12:21:25Z")
Eugenically, isn’t sibling breeding a _good_ thing? Any potentially dangerous recombinants they have go ahead and recombine, and eliminate themselves from the gene pool. Any offspring that don’t croak are, statistically, likelier not to have the recombinants. The average quality of the offspring goes up. (That’s very tersely and inexactly expressed, of course, to say nothing of callous, but as long as we’re being all objective about this, why worry?) ---
**Author:** ![GomiBoy](https://avatars.discourse-cdn.com/v4/letter/g/b2d939/32.png) [@GomiBoy](https://boards.straightdope.com/u/GomiBoy)\ **Post date:** [February 3, 2005, 12:27pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/25 "2005-02-03T12:27:23Z")
I think the problem with brother-sister (or brother-brother) incest is not a big deal, to be honest. There’s the genetic angle to think of, but hey, if they don’t plan on procreating it’s no skin off my back. I am also sure it happens a lot more than people talk about, especially in less-developed countries. Now, on the other issue, the parent-child incest one, that’s a whole different issue. It’s a question of power and such to me. The parent will always be seen as a ‘power’ figure, even after the child is grown, so how realistic is it that a parent-child consensual relationship really is consensual? I think it’s a morally slippery slope. Similar to teacher-student relationships, to a degree. A student can hook up with a teacher after that teacher isn’t the student’s teacher anymore (try saying that one three times fast! :)), and I wouldn’t look askance at that, but you don’t stop being someone’s parent or someone’s child. ---
**Author:** ![Windwalker](https://avatars.discourse-cdn.com/v4/letter/w/5e9695/32.png) [@Windwalker](https://boards.straightdope.com/u/Windwalker)\ **Post date:** [February 3, 2005, 2:18pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/26 "2005-02-03T14:18:24Z")
I too am in the If-They’re-Consenting-Adults-Let-Them-Get-It-On crowd. It seems that the main reason it’s not allowed is because of the religious and “ick” factor. The genetic factor is an issue, but we clearly let people with all sorts of nasty genetic diseases breed, so it shouldn’t be a dealbreaker. In any case, if the genetic issue were the only societal issue that kept it from happening, you could make incestual breeding illegal, but not incestual relationships. But, in the interests of strategy, I think it would be better to first get gay marriage approved before even bringing other sexual issues to the national debate. If gay marriage were linked to incest, we’d prolly be staring at another 100 years before complete national legalization… ---
**Author:** ![Ol\_Gaffer](https://avatars.discourse-cdn.com/v4/letter/o/8e8cbc/32.png) [@Ol\_Gaffer](https://boards.straightdope.com/u/Ol_Gaffer)\ **Post date:** [February 3, 2005, 6:00pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/27 "2005-02-03T18:00:58Z")
There is some biological evidence for the incest taboo, suggesting that not screwing your brother/sister is more than just “conditioning.” It’s called the **Westermark Effect** (also called the Familiarity Hypothesis) and it suggests that “animals are not sexually stimulated by the individuals with whom they interact during critical periods in their early lives (Gray 1985:198).” While siblings are the most obvious candidate for someone with whom you interact with during these critical periods, the evidence extends the Effect even to _non-related_ individuals with whom you were raised. Further, even in the cases where sexual activity occurs, these relationships have much lower rates of reporductive success and, when marriage occurs, much higher rates of divorce (Gray 1985:215). If this is the case, then perhaps “conditioning” is what causes the incest…not what precludes it. Reference: Gray, J. Patrick 1985 _Primate Sociobiology_. HRAF Press, New Haven. ---
**Author:** ![davenportavenger](https://avatars.discourse-cdn.com/v4/letter/d/5f8ce5/32.png) [@davenportavenger](https://boards.straightdope.com/u/davenportavenger)\ **Post date:** [February 3, 2005, 8:11pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/28 "2005-02-03T20:11:10Z")
> [@Windwalker](#): > > The genetic factor is an issue, but we clearly let people with all sorts of nasty genetic diseases breed, so it shouldn’t be a dealbreaker. Yes, but people who already have genetic diseases can’t help it. Forbidding them to breed would be cruel because their genes were caused by forces outside their control. But when you breed with a sibling, you’re knowingly exposing potential children to problems. You’re creating a genetic disease where none existed. > [@Age Quod Agis](#): > > Marriage and procreation are considered fundamental rights under the Constitution. Really? I’m sure that millions of gays as well as thousands of Native Americans and mental patients who were sterilized by the state would call you on that. ---
**Author:** ![Age\_Quod\_Agis](https://avatars.discourse-cdn.com/v4/letter/a/d07c76/32.png) [@Age\_Quod\_Agis](https://boards.straightdope.com/u/Age_Quod_Agis)\ **Post date:** [February 3, 2005, 9:05pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/29 "2005-02-03T21:05:29Z")
> [@continuity eror](#): > > Really? I’m sure that millions of gays as well as thousands of Native Americans and mental patients who were sterilized by the state would call you on that. Really? Thousands of mental patients? _Millions_ of gays? Can I have a cite, please? Anyway, those people wouldn’t be calling _me_ on anything. They’d be calling the United States Supreme Court. [Marriage is a fundamental right.](http://www.law.umkc.edu/faculty/projects/ftrials/conlaw/loving.html) > [@United States Supreme Court in Loving v. Virginia](#): > > Marriage is one of the “basic civil rights of man,” fundamental to our very existence and survival. [url=]Procreation is a fundamental right. > [@United States Supreme Court in Skinner v. Oklahoma](#): > > We are dealing here with legislation which involves one of the basic civil rights of man. Marriage and procreation are fundamental to the very existence and survival of the race. ---
**Author:** ![recurriman](https://avatars.discourse-cdn.com/v4/letter/r/8dc957/32.png) [@recurriman](https://boards.straightdope.com/u/recurriman)\ **Post date:** [February 4, 2005, 4:05am UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/30 "2005-02-04T04:05:43Z")
> [@Rune](#): > > Of course not. But tests with rats show they’ll pick a mate not of close kin if given the choice. No reason to think the taboo amongst humans don’t involve elements of both social conditioning as well as instinctual behaviour. Well then, I stand corrected! > [@Rune](#): > > The negative (as well as positive) genetic consequences will manifest themselves in 1 generation. Currently cousin marriage amongst Arab immigrants in Denmark results in significant higher rate of birth defects. Positive consequences? How surprising! Could you give some examples? ---
**Author:** ![rfgdxm](https://avatars.discourse-cdn.com/v4/letter/r/c0e974/32.png) [@rfgdxm](https://boards.straightdope.com/u/rfgdxm)\ **Post date:** [February 4, 2005, 4:15am UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/31 "2005-02-04T04:15:55Z")
> [@continuity eror](#): > > Really? I’m sure that millions of gays as well as thousands of Native Americans and mental patients who were sterilized by the state would call you on that. Note: the USSC has never ruled that marriage is other than a union between a man and a woman. Thus when the USSC ruled marriage is a basic civil right, they weren’t thinking about gays. “Gay marriage” is a logical impossibility of the definition of marriage depends on it being between people of the opposite sex. ---
**Author:** ![villa](https://avatars.discourse-cdn.com/v4/letter/v/bc79bd/32.png) [@villa](https://boards.straightdope.com/u/villa)\ **Post date:** [February 4, 2005, 4:20am UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/32 "2005-02-04T04:20:50Z")
> [@Rune](#): > > The negative (as well as positive) genetic consequences will manifest themselves in 1 generation. Currently cousin marriage amongst Arab immigrants in Denmark results in significant higher rate of birth defects. Really? Is there a trustable cite to this as I was under the impression recent research was showing the genetic concerns to be overblown. My problem with incest comes from the supposition I have that it is overwhelmingly abusive. As such the state can regulate (or ban it) even if it does infringe on the rights of the minority of cases where it is not abusive. I’ll confess up front to not having evidence to hand on that, though. ---
**Author:** ![Sublight](https://avatars.discourse-cdn.com/v4/letter/s/439d5e/32.png) [@Sublight](https://boards.straightdope.com/u/Sublight)\ **Post date:** [February 4, 2005, 5:50am UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/33 "2005-02-04T05:50:15Z")
> [@Age Quod Agis](#): > > Really? Thousands of mental patients? _Millions_ of gays? Can I have a cite, please? I think that was meant to be read as ‘thousands of mental patients who were sterilized’ and ‘millions of gays who aren’t allowed to marry’, but I can give you a cite on the sterilizations: [http://www.cfif.org/htdocs/freedomline/current/in\_our\_opinion/un\_sterile\_past.html](http://www.cfif.org/htdocs/freedomline/current/in_our_opinion/un_sterile_past.html) > [@](#): > > In 1907, Indiana became the first state to pass a law permitting involuntary sterilizations on eugenic grounds; at least 30 states would follow suit. Many of them simply adopted a model “eugenical sterilization law,” crafted by the ERO’s Harry Laughlin, which called for compulsory sterilizations of the “socially inadequate.” By the mid-1920s, more than 3,000 people had been sterilized against their wills. These included the homeless, orphans, epileptics, the blind and deaf. Also sterilized were those who scored poorly on IQ tests, who were diagnosed as being “feebleminded.” > > … > > the U.S. Supreme Court in the landmark case Buck v. Bell (1927), ruled 8-1 to uphold the sterilization of Ms. Buck on the grounds she was a “deficient” mother. Chief Justice Oliver Wendell Holmes Jr., an adherent of eugenics, declared “Three generations of imbeciles are enough.” > > … > > May 2, 2002, marked the 75th anniversary of the shameful Buck v. Bell decision, which has never been overruled and was cited in a federal appeals case as recently as last year. The Court’s action in Buck led to the forced sterilization of more than 65,000 Americans by 1979. The website also provides additional citations. You can also google ‘eugenics’ and '‘sterilization’. _In the Name of Eugenics_ by Daniel Kevles is a good, though somewhat dense, read. ---
**Author:** ![Rune](https://avatars.discourse-cdn.com/v4/letter/r/e68b1a/32.png) [@Rune](https://boards.straightdope.com/u/Rune)\ **Post date:** [February 4, 2005, 9:47am UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/34 "2005-02-04T09:47:15Z")
> [@recurriman](#): > > Positive consequences? How surprising! Could you give some examples? No specific. But breeding close kin is a common practise in husbandry and pet breeding when you want to bring out certain specific traits. The same happens in human close kin breeding. The bad as well as the good is crystallised and emphasised. > [@villa](#): > > Really? Is there a trustable cite to this as I was under the impression recent research was showing the genetic concerns to be overblown. A cite for what? That the effect will be there after 1 generation or that cousin marriage has shown to increase the number of inherited defects? The effects of inbreeding is not something which magically appears after X generation. The consequences are accumulative but felt from generation 1. Whether it’s anything to worry about in generation 1 is another question. The number of children born with severe handicaps living in Copenhagen has increased by 100% within the last 10 years. This is given as a result of: A) Higher age of mothers. B) More children survive. C) A larger immigrant community where cousin marriage is more common. Here is “Ugeskrift for læger” (Weekly Journal for Doctors) which is the (modest) Danish version of the Lancet. > [@](#): > > This increased risk of consanguinity couples in relation to non-consanguinity couples in having children with inborn defects is found in several surveys (Table 1). It is shown that the risk of having children with such defects is generally found to be around 2 1/2 times higher for consanguinity couples. It is further shown that the rate of defects in children of uncle-niece marriages (9,34%) is higher that of cousin marriages (6,18%). > > […] > > It appears that consanguinity couples have an increased risk of having children with born defects. The risk for birth defects is increased by 2-2.5 in relation to the background risk, which in Denmark currently is around 3%” > > Denne øgede risiko for konsangvine i forhold til ikkekonsangvine for at få børn med medfødte misdannelser kan genfindes i flere studier (Tabel 1). Man ser, at risikoen for at få børn med medfødte misdannelser gennemgående er fundet at være ca. 21/2 gange højere for konsangvine end for ikkekonsangvine. Det er desuden vist at incidensen af malformationer er højere for børn af onkel-niece-forældre (9,34%) end for børn af fætter-kusine-forældren (6,18%). > […] > Af litteraturen fremgår det, at konsangvine par har en forøget risiko for at få børn med medfødte misdannelser. Risikoen for føtale misdannelser er forhøjet 2-21/2 gange i forhold til baggrundsrisikoen, som i Danmark er på ca. 3% [http://www.dadlnet.dk/ufl/2003/0318/VP-html/VP40063.pdf](http://www.dadlnet.dk/ufl/2003/0318/VP-html/VP40063.pdf) Here’s some from Norway: > [@](#): > > Another survey from England with 4,934 children (Bundey og Alam, 1993) showed that the mortality and severe sickness is tripled in children of cousin marriages. 60% of the mortality amongst these children could be removed if there were no cousin marriages. In the group which partook in the survey were around 10% of the five year old children of cousin marriage either dead or affected by a severe sickness, typically mental retardation. > […] > There are older surveys which reveals that children of cousin marriages score somewhat less on IQ tests (Plomin et al, 1980, Bittles, 1994). > > Et andet studie fra England med 4.934 børn (Bundey og Alam, 1993) viser at dødeligheden og svær sygelighed er tredoblet blandt børn af fætter-kusine ægteskaber. Faktisk kunne 60% af dødeligheden blandt disse børn fjernes, hvis der ikke var fætter-kusineægteskaber. I den gruppe, der indgik i dette studie var ca. 10% af de femårige børn med fætter-kusine forældre enten døde eller påvirket af svær sygdom, typisk mental retardering. > […] > Der findes ældre studier, der viser at børn af fætter-kusine-ægteskaber scorer lidt lavere på forskellige intelligenstests (Plomin et al, 1980, Bittles, 1994). [http://www.rights.no/webtekst/artikler/faetter-kusine-notat-norge.pdf](http://www.rights.no/webtekst/artikler/faetter-kusine-notat-norge.pdf) Here’s another source, from Centre for Human Genetics, on consanguinity marriage: [http://www.consang.net/summary/01AHBWeb3.pdf](http://www.consang.net/summary/01AHBWeb3.pdf) I don’t know if one can assume the effects of sibling marriage is twice that of cousin marriage, given that they share twice the number of genes. Probably not, but I think it’s safe to assume the effects are greater. Whether the concerns are overblown depends on what they were presentes as being. ---
**Author:** ![gouda](https://avatars.discourse-cdn.com/v4/letter/g/c77e96/32.png) [@gouda](https://boards.straightdope.com/u/gouda)\ **Post date:** [February 4, 2005, 10:34am UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/35 "2005-02-04T10:34:19Z")
A [thread](http://boards.straightdope.com/sdmb/showthread.php?t=155579&highlight=incest) on the same topic. ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [February 4, 2005, 12:59pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/36 "2005-02-04T12:59:48Z")
I’ve just been reading the novel _Middlesex_ by Jeffrey Eugenides, about a kid whose grandparents had been brother and sister… on top of that, his parents were cousins… and this concentrated a recessive gene that produced an intersexed child. Raised as a girl, turned into a boy during adolescence. The novelist cited a scientific paper on 5-alpha-reductase gene defects, something something, as a basis for the novel’s plot. As genetic screwups go, this one was fairly benign. Just a change of gender. Could have been something much more unpleasant. ---
**Author:** ![Anaamika](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@Anaamika](https://boards.straightdope.com/u/Anaamika)\ **Post date:** [February 4, 2005, 2:53pm UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/37 "2005-02-04T14:53:03Z")
> [@Age Quod Agis](#): > > If it’s what they want, and it doesn’t effect me, then go for it. I hate to be a pedant, but it looks like i’m going to be one today. You want to use _affect_. Effect is the wrong word here. Other than that I agree with you. Like someone else said, you only go around once and it’s already so difficult to stay happy in this world. ---
**Author:** ![Scissorjack](https://avatars.discourse-cdn.com/v4/letter/s/c67d28/32.png) [@Scissorjack](https://boards.straightdope.com/u/Scissorjack)\ **Post date:** [February 6, 2005, 1:12am UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/38 "2005-02-06T01:12:02Z")
> [@Anaamika](#): > > I hate to be a pedant, but it looks like i’m going to be one today. Ah, irony too rich and thick to spread on toast. {I hate smileys, so consider that to be typed in a humorous and non-condescending manner} ---
**Author:** ![Grrr](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/grrr/32/146_2.png) [@Grrr](https://boards.straightdope.com/u/Grrr)\ **Post date:** [February 6, 2005, 8:41am UTC](https://boards.straightdope.com/t/why-is-incest-so-bad/288075/39 "2005-02-06T08:41:57Z")
Donny and Marie Osmond seem to be a fairly happy couple. [Previous page](https://boards.straightdope.com/t/why-is-incest-so-bad/288075.md?page=1)