If there is no power imbalance or manipulation in the form of grooming, if it is consensual and between adults then I haven't got a problem, even knew a pair of sisters who regular satisfied each others needs rather than bring a strange man into a household with a small child, they just figured it was the safer alternative. However all the conditions have to be met and they were in that case, usually they aren't.
Genetically speaking line breeding is often used in studs to fix traits so if you had two particularly fine specimens with highly desirable traits I wouldn't even insist on safe sex, but you'd want a full genetic screening first which is kind of hypocritical considering society has no problems with two individuals with known inherited illnesses from having children.

More men will vote for moral than women. This question was probably brought to you by a male, which is why people are on here trying to hook up.

If consenting adult siblings decide to have sex, it is only their business - as long as they don't procreate. it supports the freedom of choice, not harming a third party.

Unwise due to genetic concern s. Immoral because it generally involves a violation of trust or.misuse of power.

I think that it is a religious thing in general, not just a "Christian" thing. But being more of a spiritualist, I still think that somehow a sexual relationship between siblings of any combination is a bit creepy. Just my opinion.

This has become more of an issue in modern times with the rights of adopted people to find their biological family. Apparently There is a 25% chance of sexual attraction in the case of each individual. Doing the maths that means that 6.25% of the times it will be mutual.

NO if for no other reason than my brother has major cooties!

I consider it immoral, in the sense that it can be harmful for society. I remember learning in sociology class that incest is a taboo because family members usually have very easy access to one another, and also that if such behavior became normal, that it could cause confusion in social roles. this makes sense to me. However, I don't believe it is something gross or horrible; it's just something we should not do for good reasons, and it is taboo because if it weren't, it would probably become commonplace. But for those who consider truly terrible and disgusting, what is it about it precisely that makes it so? I don't approve of incest, but it doesn't horrify me either.

I don't believe that any relationship between two or more consenting adults is immoral. There is a story in the bible, after the fall of Sodom and Gomorah, Lot's daughters had children by their father and weren't punished by god. As long as nobody gets hurt, It's there business

Morals are subjective. To each their own. It's not my place to judge others, or their actions. I've always said, what two consenting adults do in private, is no business of mine.

Morality is a social construct.
Biological, inbreeding leads to the collection of heterogeneous mutations and can lead to reduced fitness. The incest taboo is much older than Christianity and has nothing to do with it. It came from thousands of years of observations. In the past, they used myth stories to show people that it was "wrong".
So if you want to get fixed and have sex with your sister or brother, whatever.

Well that's an odd thing to include... I would say no sex is 100% "safe", assuming what's meant is avoiding both disease and pregnancy alike. Protections can fail and often enough do.

To me risking it with family is just not right. Even if it was limited to siblings, it just seems playing around with the possibility is nasty.

I believe we are psychologically preprogrammed not to engage in sex with people we are close to During certain formative years. Generally I think from age 7 to about 14. So really, brother and sister sex is gross but so is all sex (when done properly.) The difference is we have developed a mechanism that grosses us out at the thought of sex with certain people we have bonds with during a particular time period.

If incest is practiced in a manner in which it is not abuse then I (putting my gross factor aside) would say it is Amoral.

I think its not a moral issue at all its one of genetics you haven't such a wide gene pool between you so it just makes sense to have children with non-close relatives

I just finished a book “The righteous mind” that discussed the origins of morality and used this example: an adult brother and sister decide to have sex, use double protection and never tell anyone. Is this immoral? Lots of people said yes, but couldn’t explain why. It doesn’t hurt anyone, they are adults, there is practically no chance of reproducing. It’s just yucky. There’s an evolutionary basis for our finding it yucky, that no longer applies, but we still have the same emotional reaction to it. We would prefer to have a rational explanation for why it’s wrong, but many people will go with their gut feeling even if they know it doesn’t make rational sense.

This is really a great question which must be viewed with an open mind. I never had a sister and do wonder sometimes if I, as a youngster could have " crossed the line. ". This is where ones conscience is the guiding force. There are some norms which one follows in order to retain self respect, for yourself and your vulnerable sister, I say don't ever disrespect your siblings.
Practically speaking, the chance of inbreeding defects is natures way of deciding against it.

From a biological and evolutionary point of view, sex among close relatives is not advantageous because of the possibility of decreasing genetic diversity and increasing the chances of offspring having genetic disabilities (being homozygous for bad genes.) Boys and men normally have an instinct not to be sexually attracted to sisters if they were raised together.

I honestly am indifferent... The only real problem with it is the genetic defects that are bound to happen from incest otherwise the actual act of having sex with a relative isn't really any of my buisness

I don't judge it. I hold the view that what consenting adults do is nobody's business. If that can be true with gay relationships, that can also be true with incestuous relationships. I wouldn't advise conceiving children for genetic reasons but there are options. Birth control exists. There are also many cases where it's gay incest. Nobody has to understand it. But then again when does anybody understand what love is going to do?

More taboo than moral/immoral (a false dichotomy). The taboo, according to various sociologists to whom I've spoken, is more about extending social links and familial networks than avoiding genetic disorders. Human beings survive because they form societies, a lone human is mere fresh meat to most of the world. Extending links through marriage in those societies has always been vital to our survival as a species.

I think its a taboo more then a morality issue , the thought creeps me out Bad for the gene pool at any rate

I caught a friend of mine in Texas in the shower with his sister (both adults). He later just smiled and said "Incest is Best", all I could do was laugh and forget it. They were certainly enjoying themselves, I'll say that.

The "Game of Thrones" scenario in which adult siblings who are more or less peers mutually desire one another sexually to enough of a degree that they overcome the social taboo and consummate their mutual desire is vanishingly rare in real life. If you came to me with that scenario, I'd probably say, "Sure, that's taboo, but it's not immoral."

But that's not most incest. Most incest is a (usually male) family figure with a lot of power using that power to sexually exploit a younger, relatively powerless child (who may be of any gender). And it does lasting, severe damage to that child's psychology. The damage may manifest in different ways as the child ages, but it's never good and it takes a LOT of time and a LOT of painful effort to overcome.

So, that's why I voted "immoral." We're not just talking about a social taboo. We're talking about rape, up to and including parents raping their children. Very immoral, because very harmful.

It's not about morals. It's about why the fuck would anyone do it?

There must be something wrong with you Mer-cains.