What is it that makes incest wrong?

Because if you end up getting pregnant your child is 7% more likely to have birth defects.

And if incest is done multiple times with the same lineages, it will get to a point where you are guaranteed to give birth to a baby with crippling birth defects.

As long as you refrain from reproducing via other relatives you are fine...

@Chipper

NO, the difference is HUGE.

Incest done long term will keep giving birth to more and more defective children until they are either still-born or unable to reproduce.

Whether it would be moral to reproduce with someone who has a genetic disease depends on how severe that disease is and if you think you would be willing to live with it...

every single culture/society has developed some sort of taboo against incest because of increased chances of genetic mutations. They surely must have realized that the mutated babies were somehow correlated to incest. Think of how the ancient people would have felt about something being born with a horrible defect. They didn't know science, and probably would have assumed that it was the work of the devil or something. So a taboo would have developed.

Which is why today, breeding with those who have certain genetic defects are seen as less taboo than incest. The taboo is no longer rational, and it has been ingrained into society. Unlike breeding with those with genetic defect. No one thinks it is "gross" to have sex with someone who has PKU (autosomal recessive defect). Same concept, no taboo.

Objectively, there is nothing wrong with incest as long as both parties are consenting, and doesn't hurt anyone, or anyone who can come into existence (contraceptives). However, public opinion on any matter is rarely objective.

Congratulations for actually THINKING and seeing that the only thing that makes consensual incest "wrong" is a religious prohibition. In the Bible, it was forbidden to the ancient theocracy of Israel, along with eating shellfish, perhaps to distinguish Israel from every other nation around it, especially Egypt. Consensual incest was widely practices by the other nations, including the royalty of Egypt.

CONSENSUAL incest is not wrong. (Abuse victims: being abused by a relative does not make it wrong for others to have consensual incest, any more than rape by a stranger makes all sex wrong. Sex and assault/molestation are two different things.) An aversion became common in humans that aided in population growth as one disease couldn't wipe out the human race. That's not a problem anymore.

Consensual incest is very common. You know people who have been involved, whether you know it or not.

There is no rational reason for keeping laws or taboos against consensual incest that is consistently applied to other relationships. Personal disgust or religion is only a reason why one person would not want to personally engage in what I call consanguinamory, not why someone else shouldn't do it. An adult should be free to share love, sex, residence, and marriage with ANY consenting adults. Youthful experimentation between close relatives close in age is not uncommon, and there are more people than you'd think out there who are in lifelong healthy, happy relationships with a close relative. It isn't for everyone, but we're not all going to want to have each others' love lives, now are we?

Some people try to justify their prejudice against consanguineous sex and marriage by being part-time eugenicists and saying that such relationships inevitably lead to “mutant” or “deformed” babies. This argument can be refuted on several fronts. 1. Some consanguineous relationships involve only people of the same gender. 2. Not all mixed-gender relationships birth biological children. 3. Most births to consanguineous parents do not produce children with significant birth defects or other genetic problems; while births to other parents do sometimes have birth defects. 4. We don’t prevent other people from marrying or deny them their reproductive rights based on increased odds of passing along a genetic problem or inherited disease. It is true that in general, children born to consanguineous parents have an increased chance of these problems than those born to nonconsanguineous parents, but the odds are still minimal. Unless someone is willing to deny reproductive rights and medical privacy to others and force everyone to take genetic tests and bar carriers and the congenitally disabled and women over 35 from having children, then equal protection principles prevent this from being a justification to bar this freedom of association and freedom to marry.

Some say "Your sibling should not be your lover." That is not a reason. It begs the question. Many people have many relationships that have more than one aspect. Some women say their sister is their best friend. Why can’t their sister be a wife, too?

Some say “There is a power differential.” This applies least of all to siblings or cousins who are close in age, but even where the power differential exists, it is not a justification for denying this freedom to sex or to marry. There is a power differential in just about any relationship, sometimes an enormous power differential. To question if consent is truly possible in these cases is insulting and demeaning.

Some say “There are so many people outside of your family." There are plenty of people within one’s own race, too, but that is no reason to ban interracial marriage. So, this isn't a good reason either. Let consenting adults love each other the way they want!

It doesn't just lead to "genetic defects;" it leads to a genome that's not viable.

Here, maybe this will help:

http://en.wikipedia.org/wiki/Inbreeding

I don't care about the "bible" or the "quran" or any religious superstitions. I care about the long-term viability of the human genome. Incest is *stupid.*

Fortunately, it's also very rare among humans -- an aversion to it was naturally selected for among humans long, long ago. Lots of other animals as well.

Nothing is wrong with incest as long as the teenage brother and sister love each other very much, they both want to have sex, and they use either condoms or birth control pills.

Tasmania. The Cambridgeshire Fenlands. Pitcairn Island. The Appalachians. I rest my case.

Interestingly, it is not just a rural pastime. Research indicates that the inhabitants of many inner city estates in London and other large cities have been closely sharing the same gene pool for about four generations, certainly since WW2.

genetic deterioration.

If the problem is genetics, wouldn't it be equally wrong to be with someone who is known to carry defective traits that are passed genetically?

yes it is, in some countries the govt regulate marriages of thallasemic people. and incests create a much wider genetic defect possibilities.

Personally, i find incest disgusting and would never take part in it. However, I'm of the belief that as long as both people are consenting adults, they should be allowed to do whatever they want.

And I'm athiest.

Incest is one of the most beautiful things in the world. There's no better way to show a relative how much you love them, then by fuking them. You should have sex with your mom, sister, daughter, whatever everyday.

In my opinion, there is nothing that makes incest wrong, so long as it is consensual. All that truly matters is that everyone involved is happy together.