There should be a third option..like depends. Because if people were separated for years through adoption or father was a sperm donor..if they somehow found one another and started a relationship..only to find out later on they were related..how can we as a society deny them when they were not aware of the relation? If two men and two woman either twins or brothers and sisters close in age start fool around..its taboo and morally wrong but if god does not exist like most of us believe..how is anything immoral? Who makes these rules? As long as you are not causing harm to others who cares what someone does. So I guess incest is fine in my book within reason..appropriate ages..and situations..and 100% safe sex so children can not be spawned from such actions.

I find this hard to vote for one way or the other. Incest may be an emotionally safe scenario if there's no power-play going on, as siblings know each other well and (if raised well) have healthy trust for each other. On the flip side, there is SUCH a stigma attached to it, their lives would be devastated if found out. Why risk it? So, I can't make a moral judgement, as I think that is a false dichotomy based on an outmoded value system. I think what I'm saying is that morals are a construct that can be good or bad.

(...see what I did there???)

First, a Christian has no way to oppose incest because it is practiced quite a bit in their religion. Second, it might not be moral or immoral. Third, in the vast majority of cases I guess it would be immoral because of the family dynamics involved. Fourth, consider the strongest case of sibling incest that might be not immoral, two people who do not know each other at all and never find out they are siblings. In that case, I don't know. Fifth, safe sex doesn't mean no pregnancies. It is difficult to not have revulsion for the idea.

Ironically, in the Biblical worldview, incest is not only acceptable but is the very way in which our species has survived - twice. Adam and Eve, then Noah and his happy little family. Disregard the fact that such a situation is biologically impossible. Anyway, back to the real world.

Incest itself is neither moral nor immoral. It would be immoral for children to come from such a relationship, because inbred children have a very high chance of being born with a genetic disorder. However, incest itself is no more moral nor immoral than gay, lesbian, anal, oral sex or all the other kinky categories one can find on Pornhub.

I think that the general aversion to incest goes back well before Christianity, so it's not just based on a religious taboo. It also seems to be very rare among most higher animals, certainly the primates, although there are exceptions, and sexual curiosity (I.e. exploratory, rather than penetrative sex) often occurs in animal family groups.
When a female animal comes into heat, and emits pheromones, it seems that generally other siblings in the group are not attracted by those pheromones, so there's a biological restriction against it.
One of the main human objections to it is that we generally have a different sort of relationship with close relatives to the sort of relationship that leads to a 'normal' sexual attraction.
That's why the cases where siblings have been raised apart and then happen to meet, not knowing that they are related, and fall in love and have sex, are so interesting, and so hard to condemn. It basically goes back to my point that the relationship you have with the person that you know is your brother or sister, and that you were raised with, is not the sort of relationship; that usually leads to sex.
But, with all the caveats and qualifications that have been mentioned by the poster and others (safe, consensual, adult, etc), then there's no a priori reason why it should be wrong.

I find this gross because i was raised to believe it is gross. People are taught from birth what is moral or immoral . There is no answer to this question because morals are derived from cultural and society upbringing. Incest occurs in the animal kingdom

Neither. Incest takes place in many societies and over 400 animal species. Is first cousin sex/married incest? Hundreds of societies do it. Best to avoid it in the immediate family for emotional reasons.

I wasn't sure just how to answer this question, but after serious consideration, I can find no scientific reason why 2 consenting adults should not have safe sex.

I have to say my brother sister and I were abused sexually by our much older uncle; so knowing that that is the most common occurrence of incest it is IMMORAL.

Having said that our DNA and genetic make up passes along our genes, and humans are susceptible to damaging genetic combinations which cannot be weeded out by stronger genetics when there is incest resulting in pregnancy. Wild animals display almost no signs of incestuous relations ships, unlike homosexuality.

If you were in an adult consensual sexual relationship with your sibling, would you be able to tell your best friend? Your parents? Talk about it with the girls over cocktails? Laugh about the queef you let loose after getting pounded all night by your BROTHER?! Man, I don't know about morals but I do know if you hide or lie about things, it's usually because you know it's not right.
I don't have brothers but have thought "if I had a brother and he was a hottie, would I ever find myself sexualizing him?" I can be a bit of a floozy! But I'm pretty sure I wouldn't be able to introduce him as my new boyfriend at the office party. "Oh, tell us all how you met!"
"Mom brought him home from the hospital when I was 2."

Honestly,. I don't think morality is the issue here. Birth defects are. Personally I could care less if a brother bonks his sister, but if they breed it's going ot lead to some very serious problems...ones they probably can't afford that my taxes will have to take care of. I'm very much on the side of parents with disabled kids or children with birth defects except when those birth defects were knowingly done. I don't stand with parents who birthed a fetal alcohol baby, I don't stand with parents that brought crack babies into the world and I don't stand with iincestual couples who breed kids with birth defects. If you're family and want to f*ck, get fixed. Then you can do whatever you want.

Stepping away from religion is easy for me but I am not an atheist. Please remember that my comment is strictly opinion based. On the subject of incest, I consider it immoral, there are so many people out there in the world for someone to find a mate. The fact that a family has a bond that we all respect and understand is something to take into account. Say a brother and sister commence in the sexual act together and become pregnant. should the abort the child because society will judge them, are they taking into account the possible problems that the child is going to grow up with? ie: my daddy uncle is sick and my aunty momma is mad cause family won't help them.

I love my family but to lay with them in the act of love is something that pulls into question one's sanity and the clarity of the situation when presented to them. personally, I could not do it because I am not attracted to my sisters that way.

thats why there is health issues.We found a work around called contraception so its all good to sleep with mummy,hell why stop there we have the whole animal kingdom lets start doing them aswell.No contraception gives a 100% guarantee so its wrong.Just because we can does not mean we should.Muslims practice incest first cousins but it has been proven many of them ignore the rules and have to hide away or evan kill the end product..I don't think wild animals practice incest its probably just a human thing.we need to live by some standards i think,first comment so go easy on me guys and gals and all the other sexes out there

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.

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.

If it is safe sex, as stated, and the two people are adults I see no problem. The issue of incest has been mostly due to religious restrictions and due to the fact that if children are born from the union of the two people certain genetic abnormalities are very possible. As long as there are no children from the union then who am I, and why would society, have anything to say about two people enjoying each other sexually. Interestingly, due to my upbringing, my emotions are telling me to take away what I have just written above, but my mind over rules and says that if two consenting adults choose to enjoy a sexual union without children, why not?

Well...if you are looking at it from the biological perspective of reproduction, there is that risk of passing on genetically inherited flaws and afflictions (weak chins, poor vision, disabilities) so it may not be wise. On the other hand, if you don't have any genetic markers for health concerns you would strengthen your bloodline and could lead to a better, faster, stronger (depending on strengths) specimen. Kinda hard to get past the 'eww ick' factor. When you are your own aunt, things get weird. But you probably will get something better than socks and an autoharp cd for your birthday. I don't think that immoral or moral are really the best choices because morality generally is passed down through religious dogma. Better to say gross or not gross. Not easy to get out of the gross camp. If it were a social norm with which I had grown up I would likely feel differently.

Because no age parameters or relationships were given, I am going with immoral under the assumption that there is a significant age gap, disparate levels of education/power/wealth, or other inequalities that would put one party at a disadvantage. For example, a girl and her Father vs two 35 year old first cousins are vastly different scenarios.

Not something that I support.

Taboo & Both.

It's commonly not consensual and, therefore, immoral.

It's also common that separated siblings find each other. If you don't honestly know, how could anyone claim it to be immoral.

As atheists, we understand that society at large - the community as it were - dictate morality. Individuals do not. And as a society, we've deemed it "wrong"... and that is not arbitrary. In fact it's actually illegal in most states.

If we believe that incest is a normal behaviour, where is the difference between human an animals, we don't need religion for this, it's common sense.

I believe that if both parties are consenting and their intention isn't to have children, it is moral. Like other commenters are mentioning, incest can lead to birth defects and gentic mutations that would lower the quality of life for the offspring. If contraceptives or other methods are used, I see no reason why two relatives couldn't have a prosperous relationship.

Society has certain rules be you a religious or not. There are many religions, I'm sure that would welcome the practice of incest. I like to consider myself a liberal, live and let live, blah blah, but I also work in family law. The cases I have seen in 35 years with incest somehow end up to be more one-sided. Again, with the male convincing the female the it's ok. In fact look at all these people on this website that agree with me. I'm sorry but I disagree. If the only person you can find to form a loving sexual relationship with is in your immediate family, you might want to seek counseling.

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.