Why is marrying own sibling dangerous?

Is it also illegal in USA?

I think it woul be because if they decide to have kids, the kids will have defects, due to the fact that same genetics and stuff is all being transfered to him/her.

Well I come from the UK but I am certain that it is illegal in both the USA and the UK.

probly because if they have s e x and have kids they could have some funny looking babies, like one could have webbed toes, and another could have a pen!s and a v@gina, or there eyes might be oddly shaped, and some of the defects on the babies could be bad for there health or make life harder for them or something like that.

i thinks it’s because it makes the gene pool smaller for diseases and defects etc

Human cultures as far back as we can trace have had (and most continue to have) incest taboos, though the specifics vary. (Some cultures also encourage marriage between certain categories of relatives, as one can see in the Biblical book of Genesis (cousins) and more than a few royal lineages from ancient Egypt (siblings) to modern Europe (cousins). Incest taboos regulate the tension between the human impulses to mate both within the kinship circle (“endogamy” - for strong kinship ties and loyalty) and outside the kindship circle (“exogamy” - for “new blood” to expand the gene pool). The psychologist Erich Fromm made a good case that marrying one’s sibling is an infantilizing inward turn, seeking the security of the familiar, that stifle’s one’s maturation as a person who can leave the nest to encounter the world.

Marrying your own sibling isn’t dangerous…unless your dad decides to shoot you both for being ridiculous. Having a child with your sibling can cause the baby to inherit a genetic defect.

im from the US and yes its illegal here

Life has its own Rules so its dagerouse its pathetic!

It’s not “dangerous”. The only real problem lies in procreating with someone who shares your genes.

Throughout history, there have been many examples of inbreeding, which can cause physical deformities and/or mental problems. This was particularly common in royal families because they would often marry and reproduce within their own families to keep the “royal” bloodline going (they didn’t want it to be “tainted” by common blood).

One generation of reproducing within your own family (siblings, cousins, etc) is unlikely to cause problems, but over multiple generations it results in serious deformities. This is because there is no “fresh” genetic material coming in- it’s a bit difficult to explain to someone who is unfamiliar with genetics or biology. But essentially, two parents who are related will have similiar genes, both “good” and “bad”. Any child they produce will end up inheriting the “bad” genes from both parents, dramatically increasing his or her chances of things like genetic diseases, mental illness, and birth defects/deformities.

It is illegal to marry your own blood sibling in the U.S. Whether you can marry your cousin or not varies depending on state laws.

The law has to do with the medical/genetic consequences of incestual reproduction. It does not have anything to do with the fact that siblings are related or grow up together. Plenty of stepsiblings marry each other, as well as close childhood friends that grew up together. It’s not a “moral” issue or “gross”; just cruel to any potential children.

Ooh a disagreement…cool! :)

The chances of genetic defect in the fifth generation are the same as in the first, but five generations cumulatively have given the recessive “bad” genes a lot more chances to pair up.

Raelynn, you personally may find the genetic argument to be the most (or only) persuasive one, but I bet you know lots of folks where you live who would cite religious prohibitions as the determining ones for them. Even if they are wrong about the “immorality” (which I am not so sure of), I think they have the better claim on how the laws prohibiting sibling marriage originated. Incest taboos emerged waaay before anyone knew anything about genetics, and they often prohibit relationships that pose little or no risk to offspring.

Stepsibs are a good test case. No genetic danger, but people stll feel the same about it, at least if they grew up together, because they are sibs emotionally.

And of course there are plenty of cases of sibling incest happening anyway. If something doesn’t happen, there’s no need for a taboo against it.

That may be true, but I am not religious, and in this country, laws cannot be established forcing religious doctrine on others (at least in theory). People may feel sibling incest is “gross”, and it is definitely wrong if any children are produced in such a relationship, but otherwise, a romantic relationship between blood siblings is little different than a relationship between stepsiblings, cousins who grew up together, or people who are completely unrelated who grew up together. There’s no rational basis for this “gross-out” effect if there is no reproduction going on- it’s just a knee-jerk reaction, possibly to the idea of having a relationship with one’s own sibling (I do believe that having no brothers has given me a different perscpective). I don’t believe religious doctrine should be cited as a reason why sibling incest is “wrong”. I mean, if you’re religious and believe in it, great, but I think the question here was about the reason for its illegality. In the U.S., it is illegal because of inbreeding, not religious reasons- again, in theory, at least.

The genetic reasons for incest being illegal and a taboo is solid, and I agree with it. But I think people should avoid knee-jerk, gross-out reactions, in general. Thinking something is “gross” is not a good, rational arguement against that thing- just a personal feeling. I really, really, hate to bring homosexuality up in this context, but many straight (or closeted) people think homosexuality is “gross”. That in itself is not a good arguement against homosexuality- one would have to have other objective, rational arguements. Which is why I think that, when discussing sibling incest, one should stick to the rational basis for the taboo/law and not go into personal feelings.

That is exactly what i need to know, why it is dangerous and why it is illegal. Actually for those who believe in religion, that first human being were Adam and Eva (or eve), their children did marry their siblings? And why is it not allowed to day? I have a clear idea now. Thanks. :)

Raelynn, I think your analogy to the controversies about homosexuality is a good one. The laws that used to ban same-sex sexual activity, and the current laws against same-sex marriage, were not adopted directly because of a religious prohibition. As you say, the USA doesn’t (in theory) work like that. Supporters of those laws did try to make sound rational arguments for them, but I think you and I agree that those arguments were not very persuasive and were not the real basis for the laws. Rather, the laws were based on the sense of emotional disgust that many people felt toward homosexuality. That’s the same thing I’m saying about the laws against incest.

Yes, incest is genetically dangerous, and people make that argument to support banning it now. But people didn’t know about genetics when those laws first came into being, either in biblical times or in the last few centuries. Whether we approve or not, the real source of laws against incest was neither religious nor rational; it was the feeling of being grossed out. Some people (even in this conversation!) consider that to be a “natural” response to incest (or to homosexuality). I don’t, and I don’t think you do either. So if the disgust is not a simple fact of human (genetic) nature, what is the reason for it? I’m not sure Eric Fromm’s answer is right, but I cited it because I find his explanation of the origin of that emotional response better than any others I know of. I do think he gives a good reason for being wary of incest - even in the case of genetically unrelated step-siblings. Whether it justifies making incest illegal is another matter.

Sri, according to the ancient rabbinic understanding of the Bible, the fact that Adam and Chava’s (Eve’s) sons Cain and Abel of necessity married their unnamed sisters is the reason why the Torah, in forbidding many kinds of incest, specifically calls brother-sister incest a type of “kindness” (though it doesn’t show up in many English translations).