# Do incest laws apply to SSM? **URL:** \ **Category:** Factual Questions\ **Created:** [September 21, 2015, 7:53pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143 "2015-09-21T19:53:46Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [September 21, 2015, 7:53pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/1 "2015-09-21T19:53:46Z")
I thought this might have been asked recently but reasonable searches didn’t turn it up. Inspired by thoughts reading the current polygamous marriage thread… Do incest laws and other familial bars to marriage apply to same-sex partners? Could brothers or sisters marry in any US jurisdiction? World jurisdiction? What about the even odder notion of a parent marrying (post divorce or widowhood) a same-sex child? ---
**Author:** ![Mikeisskeptical](https://avatars.discourse-cdn.com/v4/letter/m/c0e974/32.png) [@Mikeisskeptical](https://boards.straightdope.com/u/Mikeisskeptical)\ **Post date:** [September 21, 2015, 8:04pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/2 "2015-09-21T20:04:15Z")
[[Legality of incest - Wikipedia](https://en.m.wikipedia.org/wiki/Laws_regarding_incest) of course they do. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [September 21, 2015, 8:11pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/3 "2015-09-21T20:11:36Z")
I guess the extension of the question is that beyond issues of societal ick factor and psychological dominance/control, incest laws are entirely about preventing overly close genetic pairing. As in other situations, but perhaps even more so, since a biological child can’t result from SSM partners, why would the law care? ---
**Author:** ![Mikeisskeptical](https://avatars.discourse-cdn.com/v4/letter/m/c0e974/32.png) [@Mikeisskeptical](https://boards.straightdope.com/u/Mikeisskeptical)\ **Post date:** [September 21, 2015, 8:32pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/4 "2015-09-21T20:32:37Z")
> [@Amateur\_Barbarian](#): > > I guess the extension of the question is that beyond issues of societal ick factor and psychological dominance/control, incest laws are entirely about preventing overly close genetic pairing. As in other situations, but perhaps even more so, since a biological child can’t result from SSM partners, why would the law care? There’s also a question about weird power dynamics with close relations I think. When people have grown up together, there’s always the uncomfortable possibility that the relationship goes back further than people would want to imagine. It’s definitely a moral grey area though. ---
**Author:** ![Mikeisskeptical](https://avatars.discourse-cdn.com/v4/letter/m/c0e974/32.png) [@Mikeisskeptical](https://boards.straightdope.com/u/Mikeisskeptical)\ **Post date:** [September 21, 2015, 8:34pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/5 "2015-09-21T20:34:57Z")
Sorry Barbarian, I see you already alluded to that aspect in your first post. I missed it first time through. ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [September 21, 2015, 8:35pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/6 "2015-09-21T20:35:36Z")
> [@Amateur\_Barbarian](#): > > I guess the extension of the question is that beyond issues of societal ick factor and psychological dominance/control, incest laws are entirely about preventing overly close genetic pairing. As in other situations, but perhaps even more so, since a biological child can’t result from SSM partners, why would the law care? Probate. ---
**Author:** ![Mikeisskeptical](https://avatars.discourse-cdn.com/v4/letter/m/c0e974/32.png) [@Mikeisskeptical](https://boards.straightdope.com/u/Mikeisskeptical)\ **Post date:** [September 21, 2015, 8:53pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/7 "2015-09-21T20:53:10Z")
> [@Bear\_Nenno](#): > > Probate. Could you elaborate? Like in the absence of a will, someone who was both sibling and partner of the deceased might be entitled to a greater share of the estate? Forgive me if that’s a stupid question, I know nothing about the law. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [September 21, 2015, 9:45pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/8 "2015-09-21T21:45:38Z")
A spouse generally gets what’s called an “elective share,” meaning if you fuck them over in the will, they can still claim some major (generally 1/3) portion of the estate. I don’t really see how that would be impacted by marriage, though. I suppose in an intestate (no will) distribution, a sibling-spouse might take half as a spouse and then a fraction of the remaining half as a sibling, but that’s unlikely. There have always been situations in which one familiar tie may give way to another (widow(er)s marrying their deceased spouses’ siblings, etc.) so the law generally makes provision for that already. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [September 21, 2015, 10:05pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/9 "2015-09-21T22:05:51Z")
> [@Amateur\_Barbarian](#): > > I guess the extension of the question is that beyond issues of societal ick factor and psychological dominance/control, incest laws are entirely about preventing overly close genetic pairing. As in other situations, but perhaps even more so, since a biological child can’t result from SSM partners, why would the law care? \*If \* 1. we were creating incest law from scratch today 2. for the sole purpose of preventing inbreeding 3. in a world where marriage customs and laws had always been gender-indifferent \*then \* you’re right that logically the law drafters wouldn’t care to legislate about SSM incest. But none of those 3 things are true in the US today. So the actual laws written decades ago contain wording like “marriage is prohibited between blood relationships closer than second cousins.” At the time that was written there was a universal assumption that the marriage was one M & one F. As always, when society changes the laws as written struggle to catch up. This is just one more example of that. Laws must be applied to novel situations as currently written until there’s the political will to rewrite them. Most laws do have a certain amount of logic behind them. But once enacted, the logic is set aside and the pure text rules. At least until a court of appeals has to interpret a tough case and digs into the logic & legislative history to insert some details the drafters forgot; ideally in accord with the best available interpretation of the record of the drafter’s intent. This is also another example of the problems that arise when people or polities try to solve a problem by managing the symptoms, rather than the cause. If you want to make inbreeding illegal, make inbreeding illegal. Don’t make other things that might possibly lead towards inbreeding, but might also lead in a lot of other non-inbreeding directions, illegal. IOW: prohibit speeding, not fast cars or good roads. ---
**Author:** ![muldoonthief](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muldoonthief/32/3188_2.png) [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)\ **Post date:** [September 21, 2015, 11:06pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/10 "2015-09-21T23:06:46Z")
Massachusetts law appears to be A-OK with brothers marrying. It specifically calls out, in separate sections, which relatives a man or a woman may not marry, and in each case, they only list opposite sex relatives: [https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter207/Section1](https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter207/Section1) Section 1. No man shall marry his mother, grandmother, daughter, granddaughter, sister, stepmother, grandfather’s wife, grandson’s wife, wife’s mother, wife’s grandmother, wife’s daughter, wife’s granddaughter, brother’s daughter, sister’s daughter, father’s sister or mother’s sister. [https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter207/Section2](https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter207/Section2) Section 2. No woman shall marry her father, grandfather, son, grandson, brother, stepfather, grandmother’s husband, daughter’s husband, granddaughter’s husband, husband’s grandfather, husband’s son, husband’s grandson, brother’s son, sister’s son, father’s brother or mother’s brother. ---
**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\ **Post date:** [September 21, 2015, 11:09pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/11 "2015-09-21T23:09:15Z")
As I recall there are some US states whose incest laws are worded gender specific saying things like an uncle shall not marry a niece. I think I read it on Straight Dope in fact. I recall this because some of the wording didn’t seem symmetric. In any case, laws worded like that would presumably not restrict a SSM between an uncle and nephew or aunt and niece. ETA: Massachusetts apparently being one of them, but a quick glance seems to show those as symmetric. ---
**Author:** ![muldoonthief](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muldoonthief/32/3188_2.png) [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)\ **Post date:** [September 21, 2015, 11:17pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/12 "2015-09-21T23:17:46Z")
Interestingly enough, MA law does NOT prevent a father-in-law / daughter-in-law marriage. I’m guessing some 1800s legislator had his eye on his consumptive son’s hot wife. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [September 21, 2015, 11:52pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/13 "2015-09-21T23:52:20Z")
> [@Amateur\_Barbarian](#): > > … incest laws are entirely about preventing overly close genetic pairing. … :dubious: Weren’t most of these laws enacted before we discovered genetics? ---
**Author:** ![Mikeisskeptical](https://avatars.discourse-cdn.com/v4/letter/m/c0e974/32.png) [@Mikeisskeptical](https://boards.straightdope.com/u/Mikeisskeptical)\ **Post date:** [September 21, 2015, 11:59pm UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/14 "2015-09-21T23:59:31Z")
> [@kanicbird](#): > > :dubious: > > Weren’t most of these laws enacted before we discovered genetics? People knew that inbreeding resulted in very physically and mentally unhealthy offspring though. The state of European royal families left little room for doubt there. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [September 22, 2015, 12:39am UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/15 "2015-09-22T00:39:28Z")
> [@muldoonthief](#): > > Massachusetts law appears to be A-OK with brothers marrying. It specifically calls out, in separate sections, which relatives a man or a woman may not marry, and in each case, they only list opposite sex relatives: > > [General Law - Part II, Title III, Chapter 207, Section 1](https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter207/Section1) > > Section 1. No man shall marry his mother, grandmother, daughter, granddaughter, sister, stepmother, grandfather’s wife, grandson’s wife, wife’s mother, wife’s grandmother, wife’s daughter, wife’s granddaughter, brother’s daughter, sister’s daughter, father’s sister or mother’s sister. > [General Law - Part II, Title III, Chapter 207, Section 2](https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter207/Section2) > > Section 2. No woman shall marry her father, grandfather, son, grandson, brother, stepfather, grandmother’s husband, daughter’s husband, granddaughter’s husband, husband’s grandfather, husband’s son, husband’s grandson, brother’s son, sister’s son, father’s brother or mother’s brother. I wonder why the MA legislature has a problem with a man marrying his wife’s mother. Certainly wouldn’t be any concerns about inbreeding. Of course, the wife in question would have to be either deceased or divorced lest you run into polygamy laws. They don’t seem to have a problem with men marrying their wife’s sister. (Again if the relationship was non-polygamous. I assume.) ---
**Author:** ![Claverhouse](https://avatars.discourse-cdn.com/v4/letter/c/13edae/32.png) [@Claverhouse](https://boards.straightdope.com/u/Claverhouse)\ **Post date:** [September 22, 2015, 12:43am UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/16 "2015-09-22T00:43:28Z")
> [@muldoonthief](#): > > Massachusetts law appears to be A-OK with brothers marrying. It specifically calls out, in separate sections, which relatives a man or a woman may not marry, and in each case, they only list opposite sex relatives: > > [General Law - Part II, Title III, Chapter 207, Section 1](https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter207/Section1) > > Section 1. No man shall marry his mother, grandmother, daughter, granddaughter, sister, stepmother, grandfather’s wife, grandson’s wife, wife’s mother, wife’s grandmother, wife’s daughter, wife’s granddaughter, brother’s daughter, sister’s daughter, father’s sister or mother’s sister. > [General Law - Part II, Title III, Chapter 207, Section 2](https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter207/Section2) > > Section 2. No woman shall marry her father, grandfather, son, grandson, brother, stepfather, grandmother’s husband, daughter’s husband, granddaughter’s husband, husband’s grandfather, husband’s son, husband’s grandson, brother’s son, sister’s son, father’s brother or mother’s brother. Under that logic with same-sex marriage a son may marry his father, and a daughter her grandmother. _That which is not forbidden is allowed_ is a fine principle, but not a universal guide. > [@Mikeisskeptical](#): > > People knew that inbreeding resulted in very physically and mentally unhealthy offspring though. The state of European royal families left little room for doubt there. Very dubious: most 19th century royalty seem remarkably tall and healthy and sane. They lived well, which in itself was a cause of _ressentiment_ to the republican saddos. I can think of only two lunatics, both with Hapsburg blood, and bith were locked up. Whereas Franz-Josef was as sane as anybody else. Besides which, in the '90s the least sane royalty was not in the habit of setting fire to people in the streets, nor of digging up their relatives as vampires and consuming the bodies as happened in America without the excuse of inbreeding. Poor families in remote villages however, in both Europe and America — and no doubt all the other continents as well ---- grew mighty strange. ---
**Author:** ![E-DUB](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/e-dub/32/403_2.png) [@E-DUB](https://boards.straightdope.com/u/E-DUB)\ **Post date:** [September 22, 2015, 12:44am UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/17 "2015-09-22T00:44:22Z")
At least the OP didn’t say: “Need answer fast.” ---
**Author:** ![Claverhouse](https://avatars.discourse-cdn.com/v4/letter/c/13edae/32.png) [@Claverhouse](https://boards.straightdope.com/u/Claverhouse)\ **Post date:** [September 22, 2015, 12:45am UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/18 "2015-09-22T00:45:03Z")
> [@muldoonthief](#): > > Massachusetts law appears to be A-OK with brothers marrying. It specifically calls out, in separate sections, which relatives a man or a woman may not marry, and in each case, they only list opposite sex relatives: > > [General Law - Part II, Title III, Chapter 207, Section 1](https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter207/Section1) > > Section 1. No man shall marry his mother, grandmother, daughter, granddaughter, sister, stepmother, grandfather’s wife, grandson’s wife, wife’s mother, wife’s grandmother, wife’s daughter, wife’s granddaughter, brother’s daughter, sister’s daughter, father’s sister or mother’s sister. > [General Law - Part II, Title III, Chapter 207, Section 2](https://malegislature.gov/Laws/GeneralLaws/PartII/TitleIII/Chapter207/Section2) > > Section 2. No woman shall marry her father, grandfather, son, grandson, brother, stepfather, grandmother’s husband, daughter’s husband, granddaughter’s husband, husband’s grandfather, husband’s son, husband’s grandson, brother’s son, sister’s son, father’s brother or mother’s brother. Under that logic with same-sex marriage a son may marry his father, and a daughter her grandmother. _That which is not forbidden is allowed_ is a fine principle, but not a universal guide. > [@Mikeisskeptical](#): > > People knew that inbreeding resulted in very physically and mentally unhealthy offspring though. The state of European royal families left little room for doubt there. Very dubious: most 19th century royalty seem remarkably tall and healthy and sane. They lived well, which in itself was a cause of _ressentiment_ to the republican saddos. I can think of only two lunatics, both with Hapsburg blood, and both were locked up. Whereas Franz-Josef was as sane as anybody else. Besides which, in the '90s the least sane royalty was not in the habit of setting fire to people in the streets, nor of digging up their relatives as vampires and consuming the bodies as happened in America without the excuse of inbreeding. Poor families in remote villages however, in both Europe and America — and no doubt all the other continents as well ---- grew mighty strange. ---
**Author:** ![UDS](https://avatars.discourse-cdn.com/v4/letter/u/ecae2f/32.png) [@UDS](https://boards.straightdope.com/u/UDS)\ **Post date:** [September 22, 2015, 1:25am UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/19 "2015-09-22T01:25:39Z")
> [@kanicbird](#): > > :dubious: > > Weren’t most of these laws enacted before we discovered genetics? Yes. Genetic explanations were retrofitted to existing incest laws. But, two things: First, even before we understood genetics, we knew that there were problems with inbreeding. We didn’t know how that worked, but we knew that it did work. Secondly, incest laws aren’t _just_ about genetic problems in offspring. It’s destabilising to both the nuclear and the extended family if family members (both blood and in-laws) are regarded as potential matrimonial partners, so we have both laws and customs which strongly discourage this. ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [September 22, 2015, 1:28am UTC](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143/20 "2015-09-22T01:28:21Z")
> [@Claverhouse](#): > > Under that logic with same-sex marriage a son may marry his father, and a daughter her grandmother. > _That which is not forbidden is allowed_ is a fine principle, but not a universal guide. If I’m reading you right, you seem to be assuming these are situations to be universally avoided. Aside from a squick factor, why should these situations necessarily be avoided? Granted, there’s would probably be some deep seated psychological issues involved in most such cases, but assuming there are no such issues and we have two mentally healthy adults, what reason is there to forbid such cases? [Next page](https://boards.straightdope.com/t/do-incest-laws-apply-to-ssm/732143.md?page=2)