# Marrying a First Cousin **URL:** \ **Category:** Factual Questions\ **Created:** [July 27, 2000, 3:52pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062 "2000-07-27T15:52:09Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![RM\_Mentock](https://avatars.discourse-cdn.com/v4/letter/r/e274bd/32.png) [@RM\_Mentock](https://boards.straightdope.com/u/RM_Mentock)\ **Post date:** [July 27, 2000, 6:17pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/21 "2000-07-27T18:17:13Z")
This subject has been discussed before, I think. IIRC, no state laws forbid first cousins from marrying, I’m even surprised that Vermont might have had such a law recently. Einstein’s second wife was his double first cousin. She had taken care of him during a long illness, and they married after. ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [July 27, 2000, 6:26pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/22 "2000-07-27T18:26:14Z")
I read a book a while back called **Race, Evolution, and Behavior** by J. Phillipe Rushton. Now, large portions of the book struck me as pseudoscientific claptrap, but it makes interesting reading nonetheless. One part of the book that I am inclined to accept as true (though I’m not 100% convinced) is the part about inbreeding.[ul][li]Many animals can somehow differentiate the members of their own species that they’re closely related to, even if they’ve never met before.[/li][li]When given a choice of mates, animals most often chose to mate with their first cousins in preference to those either more or less closely related.[/li][li]Humans share more genes with their mates than would be predicted if people chose their mates at random from within their own race. (Best friends share about as many genes as mates.)[/li][li]Spouses who are less closely related to each other than the average of mating pairs are more likely to divorce.[/li][li]My estimate, based on his data, was that spouses share in common fewer genes than first cousins, but more than second cousins.[/ul]If you have a large enough pool of potential mates to chose from, you should be able to find, by chance, a person you share a fair number of genes with, even if you’re not related.[/li] IIRC, his explanation for consanguine mating was that there must be some optimal level of interrelatedness of mates. If you’re related to your mate, your children will have that many more genes in common with you than if you and your mate weren’t related, and therefore you will be that much more likely to pass on “your” genes to future generations. However, if you’re **too** closely related to your mate, double recessives rear their ugly head. (That’s not to say that double recessives are always bad.) By the way, the notion that hemophilia in the royal households of Europe was a result of inbreeding is false. In males, hemophilia is cause by a single bad gene and is unaffected by inbreeding. Although exceedingly rate, hemophilia in females can be the result of inbreeding, since it requires two bad genes. As far as I know, there are no cases of female hemophilia in any of the royal households of Europe. The hemophilia in the royal households is usually attributed to a spontaneous mutation in Queen Victoria, or one of her ancestors. Queen Victoria’s descendants did interbreed, but in the case of hemophilia in males, that is beside the point. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [July 27, 2000, 6:28pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/23 "2000-07-27T18:28:33Z")
Why do you have a probelm with this? Royalty do it all the time and if Sandra Bullock were my cousin I’d marry her tomorrow. Well, I’m not so interested in the marriage part as to what it entails… if you know what I mean. ---
**Author:** ![SwimmingRiddles](https://avatars.discourse-cdn.com/v4/letter/s/43a26b/32.png) [@SwimmingRiddles](https://boards.straightdope.com/u/SwimmingRiddles)\ **Post date:** [July 27, 2000, 6:45pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/24 "2000-07-27T18:45:00Z")
> [@](#): > > \*Originally posted by bibliophage \* > \*\*By the way, the notion that hemophilia in the royal households of Europe was a result of inbreeding is false. In males, hemophilia is cause by a single bad gene and is unaffected by inbreeding. Although exceedingly rate, hemophilia in females can be the result of inbreeding, since it requires two bad genes. As far as I know, there are no cases of female hemophilia in any of the royal households of Europe. The hemophilia in the royal households is usually attributed to a spontaneous mutation in Queen Victoria, or one of her ancestors. Queen Victoria’s descendants did interbreed, but in the case of hemophilia in males, that is beside the point. > \*\* OK, granted I’m only working on a high school genetics background here, but wouldn’t it stand to argue that males are more prone to it, like male pattern baldness, but that females can carry it and pass the gene to thier son? Therefore the likelyhood of a boy getting the gene would be increased by inbreeding, right? ---
**Author:** ![Arken](https://avatars.discourse-cdn.com/v4/letter/a/dfb087/32.png) [@Arken](https://boards.straightdope.com/u/Arken)\ **Post date:** [July 27, 2000, 7:27pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/25 "2000-07-27T19:27:04Z")
> [@](#): > > I do watch Survivor…and I LOVE gravy fries! And you people are worried about cousins marrying? May I just say… Icky. Anyway, here in Indiana, it is illegal to get married if you are first cousins. I know, 'cause I’m getting married in two days and the County Clerk asked us if we were first cousins when we applied for the license. ---
**Author:** ![Annie-Xmas](https://avatars.discourse-cdn.com/v4/letter/a/ecc23a/32.png) [@Annie-Xmas](https://boards.straightdope.com/u/Annie-Xmas)\ **Post date:** [July 27, 2000, 8:24pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/26 "2000-07-27T20:24:33Z")
The XY heredity thing: a female carrier has one normal-X and the Hemophila-X. For a female to be a hemophiliac, she would have to have to Hemophila- X’s. This could only happen if a female carrier married a male hemophiliac (a very rare chance). The female carrier has a 50%-50% chance of passing the hemophilia-X to her children. If she passes it to her son, he will be a hemophiliac; her daughter, she will be a carrier. A male hemophiliac has a 100% chance of producing female carriers and a 0% chance of having hemophiliac sons. ---
**Author:** ![RM\_Mentock](https://avatars.discourse-cdn.com/v4/letter/r/e274bd/32.png) [@RM\_Mentock](https://boards.straightdope.com/u/RM_Mentock)\ **Post date:** [July 27, 2000, 8:33pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/27 "2000-07-27T20:33:49Z")
[QUOTE] \*Originally posted by Arken \* \*\* > [@](#): > > Anyway, here in Indiana, it is illegal to get married if you are first cousins. I know, 'cause I’m getting married in two days and the County Clerk asked us if we were first cousins when we applied for the license. \*\* I stand corrected. [Indiana’s law](http://www.state.in.us/legislative/ic/code/title31/ar11/ch1.html#IC31-11-1-2) _does_ allow first cousins to marry if they’re over 65. I guess you guys must be youngins. ---
**Author:** ![Arken](https://avatars.discourse-cdn.com/v4/letter/a/dfb087/32.png) [@Arken](https://boards.straightdope.com/u/Arken)\ **Post date:** [July 27, 2000, 8:41pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/28 "2000-07-27T20:41:18Z")
Yep. I’m 23 and the soon-to-be Missus is 22. I guess they figure after 65, there can be fun in the sack, but no chilluns to worry about. ---
**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:** [July 27, 2000, 8:55pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/29 "2000-07-27T20:55:35Z")
I don’t see it as automatic ick. Soon after I hit puberty I fell painfully in love with my first cousin, 3 years older; she was honest-to-God beautiful, achingly beautiful. But I got over it. Inbreeding is a serious problem among Indian and Pakistani Muslims with their insistence on cousin marriage. They’ve been doing it for centuries and you can see the signs it really is weakening the gene pool. A lot of birth defects and imbecility. They have traditionally done it so much because it keeps the family wealth more closely concentrated instead of dispersed to other families. But it’s time they became consicous of genetics. In the film _East is East_, the real zinger of a line came from the Englishwoman married to a Pakistani: when her children were called “half-breeds” she said, “Better _half_-breeds than _in_bred like you!” ---
**Author:** ![Hamadryad](https://avatars.discourse-cdn.com/v4/letter/h/6de8d8/32.png) [@Hamadryad](https://boards.straightdope.com/u/Hamadryad)\ **Post date:** [July 27, 2000, 9:15pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/30 "2000-07-27T21:15:58Z")
My mother is on her fourth marriage. she has made…unwise decision in the past. She is married to her first cousin. They hadn’t seen each other since he was 4 when they met again a few years ago. He’s the best thing that’s ever happened to her. They get along fantastically. She’s poorer than she’s ever been, she’s a liberal pacifist cat-lover who is now a card-carrying member of the NRA with two German Shepherds and a Rottweiler…and she’s happy as a clam. Her dad and his mom were the product of a first cousin union. My grandma (mom’s dad, obviously) is/was (he retired) a nuclear physicist, who earned his black belt at the age of 60 and now, at almost 90, still runs two miles every day. “ewwwww” all you want. As my mom likes to say: “It’s all relative, anyhow.” Heh. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 27, 2000, 10:02pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/31 "2000-07-27T22:02:00Z")
Perhaps our tolerance for consanguinous mating is too high as it is? The relevant issue is how many (potentially harmful) genes are shared between the two parents. Consider, for instance, sickle-cell anemia: The original mutation only occured once; anyone who has two genes for it (and thus has the disease) can trace their lineage back to that ancestor by at least two paths. Yes, their parents might have been seventeenth cousins, but in that particular case, it was too close. The real puzzler isn’t the incest taboo, it’s the miscegeny taboo. A child born of parents of different races is almost guaranteed to be free of genetic disorders, so why are such unions not more popular? ---
**Author:** ![Guinastasia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guinastasia/32/5751_2.png) [@Guinastasia](https://boards.straightdope.com/u/Guinastasia)\ **Post date:** [July 27, 2000, 10:36pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/32 "2000-07-27T22:36:41Z")
Good lord, the Royals have been doing it for years, as stated before. Personally, I think that’s what is wrong with Charles, Philip, and the whole lot of them…they’re so inbred it isn’t funny. Philip and Elizabeth are both descendents of Queen Victoria of England and of King Christian IX of Denmark. ---
**Author:** ![Nanook\_of\_the\_North\_Shore](https://avatars.discourse-cdn.com/v4/letter/n/bc8723/32.png) [@Nanook\_of\_the\_North\_Shore](https://boards.straightdope.com/u/Nanook_of_the_North_Shore)\ **Post date:** [July 27, 2000, 10:36pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/33 "2000-07-27T22:36:53Z")
> [@](#): > > \*Originally posted by Annie-Xmas \* > \*\*A male hemophiliac has a > 100% chance of producing female carriers and > a 0% chance of having hemophiliac sons. \*\* Thats not quite true. The female part is, the male is not. A male hemophilliac has no effect on whether or not his son is. Its comes from the mother. Therefore saying 0% is wrong. If the mother isn’t a carrier then yes, if she is a carrier there’s a 50/50 shot, and if she is one its a guarantee barring mutation or other defect. ---
**Author:** ![Guinastasia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guinastasia/32/5751_2.png) [@Guinastasia](https://boards.straightdope.com/u/Guinastasia)\ **Post date:** [July 27, 2000, 10:42pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/34 "2000-07-27T22:42:34Z")
I also read somewhere that if a hemophilliac marries a hemophilliac carrier, their DAUGHTERS can be hemophiliac…there have only been about 2 or 3 cases of this in history, and both girls died when the eventually got their periods. It was in the book Queen Victoria’s Gene: Hemophilia and the Royal Family, by the Potts brothers…an excellent book! ---
**Author:** ![Or\_n\_ry\_Oscar](https://avatars.discourse-cdn.com/v4/letter/o/9de0a6/32.png) [@Or\_n\_ry\_Oscar](https://boards.straightdope.com/u/Or_n_ry_Oscar)\ **Post date:** [July 27, 2000, 10:58pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/35 "2000-07-27T22:58:54Z")
> [@](#): > > \*Originally posted by bibliophage \* > \*\*By the way, the notion that hemophilia in the royal households of Europe was a result of inbreeding is false. In males, hemophilia is cause by a single bad gene and is unaffected by inbreeding. Although exceedingly rate, hemophilia in females can be the result of inbreeding, since it requires two bad genes. As far as I know, there are no cases of female hemophilia in any of the royal households of Europe. The hemophilia in the royal households is usually attributed to a spontaneous mutation in Queen Victoria, or one of her ancestors. Queen Victoria’s descendants did interbreed, but in the case of hemophilia in males, that is beside the point. > \*\* Good point. But I bet you wouldn’t want to take a crack at the Hapsburg jaw with the same logic. ---
**Author:** ![Guinastasia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guinastasia/32/5751_2.png) [@Guinastasia](https://boards.straightdope.com/u/Guinastasia)\ **Post date:** [July 27, 2000, 11:06pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/36 "2000-07-27T23:06:15Z")
IN the book I mentioned above, there is mentioned the possibility that Queen Victoria was a bastard… hmmmm…I doubt it though…she looked just like the Duke of Kent, her father. However, they did mention that poryphoria, an ailment that ran in her father’s family never passed through her to her descendents… ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [July 27, 2000, 11:16pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/37 "2000-07-27T23:16:46Z")
> [@](#): > > \*Originally posted by Guinastasia \* > I also read somewhere that if a hemophilliac marries a hemophilliac carrier, their DAUGHTERS can be hemophiliac…there have only been about 2 or 3 cases of this in history, and both girls died when the eventually got their periods. That may be true for sex-linked hemophillia, I don’t know. However, there is at least one other form of hemophilia that is not sex-linked. Females who have it have problems while menstruating, although with modern medicine, it’s not necessarily fatal. ---
**Author:** ![pluto](https://avatars.discourse-cdn.com/v4/letter/p/f08c70/32.png) [@pluto](https://boards.straightdope.com/u/pluto)\ **Post date:** [July 27, 2000, 11:42pm UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/38 "2000-07-27T23:42:54Z")
I just finished reading _Mansfield Park_ by Jane Austen. (WARNING: SPOILERS!) (LOL!) The entire premise of the book is built around a romance between the heroine, Fanny Price, and her first cousin Edmund. Before I read the book I read the blurb on the back cover which talked about how Fanny outdoes her wealthy, witty rival for the man she loves by being good and pure. But they didn’t mention the MSL by name and I was halfway through the book before I figured out they meant Edmund. I had been waiting for someone else to come along since she couldn’t possibly be marrying her cousin, right? Now don’t get me wrong. I like Jane Austen. I don’t mind the high moral tone of the book. But the notion that there would be no eewwww! factor for cousins marrying took me by surprise. Apparently it was a well accepted practice in England at the end of the eighteenth century. ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [July 28, 2000, 12:05am UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/39 "2000-07-28T00:05:33Z")
> [@](#): > > \*Originally posted by pluto \* > \*\*Now don’t get me wrong. I like Jane Austen. \*\* Let me be the first to say, “ **EWWWWWWWWW!** ” ---
**Author:** ![jessicala](https://avatars.discourse-cdn.com/v4/letter/j/eb9ed0/32.png) [@jessicala](https://boards.straightdope.com/u/jessicala)\ **Post date:** [July 28, 2000, 12:27am UTC](https://boards.straightdope.com/t/marrying-a-first-cousin/27062/40 "2000-07-28T00:27:09Z")
slight hijack: Are adopted siblings allowed to marry, in the U.S.? To clarify: “adopted siblings” = two unrelated people adopted into the same family and raised as siblings. I’m not saying anyone would want to do this, just wondering if it were legal in the U.S. [Previous page](https://boards.straightdope.com/t/marrying-a-first-cousin/27062.md?page=1) [Next page](https://boards.straightdope.com/t/marrying-a-first-cousin/27062.md?page=3)