I'm fairly sure most (all) of us feel parent/child incest is wrong, and for fairly obvious reasons. 

However, if a brother and sister are very careful about pregnancy prevention or, better, one or both of them is unable to conceive, what would be wrong with it?

BTW, I'm NOT trying to decide whether to do it with my sister (LOL). This is just a question that came to mind while in a discussion with another person.

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Yes, once the two primary concerns of genetic problems and abuse by one sibling of the other (primarily a much older sibling enticing a younger one into a situation where they are unable to give informed consent), then what one is left with is a social taboo with little foundation in science or even common sense.. 

If incest was 'allowed', could it become 'normal' in certain places?  And then the gene pool would reduce by a considerable factor.  Probably best to regulate against it.  

It is possible that one of the reasons for the leaps in human intelligence is because of the widening gene pool, dominant genes wiping out recessive genes, intelligence being attractive to potential mates, etc.  The last thing we want to do is reduce the size of the gene pool.

Also, considering the website we are on here, religion is spread through families.  My wife was borderline religious when I met her, believing there must be some supernatural deity somewhere who made all the mountains, flowers, cute animals and people.  Having to suffer/enjoy (delete as appropriate) every scientific and natural history programme on radio and TV and being dragged round my favourite museums for the last 25 years (she drags me round shops, stately homes and gardens) has convinced her that there is no god (or she just says that to shut me up).  My children are atheists.

I have seen many people in Walmart who probably shouldn't be allowed to procreate with anyone, imagine what would happen if they had children with their brother/sister?  The human race would be doomed!


"In the case of an increased risk of bad genes, well that argument can be equally applied to heterosexual couples trying to produce children."

From an article Inbreeding In Humans

When discussing inbreeding, one of the most important values to be concerned with is the inbreeding coefficient.  The inbreeding coefficient represents the probability that an offspring will receive a gene from each parent that is a copy of a single shared ancestral gene.  The inbreeding coefficient is zero if the parents do not share a common ancestor, and if the inbreeding coefficient is one than the offspring has a 100% chance of receiving two copies of the ancestral gene.  However, this maximum inbreeding coefficient of one cannot be achieved in human populations (Dorsten 1999).

In western civilization consanguineous marriages and human inbreeding have been frowned upon by society for some time now.  In fact, statutes passed in the 19th and early 20th centuries made inbreeding and marriages to the first cousin level illegal in the majority of the United States.  The earliest recorded study of inbreeding and its effects on human health was reported by Bemiss in 1858.  Charles Darwin became very interested and upset at this idea that children of .....

More here:


What part of 'normal' implies that everyone does it?  Homosexuality is 'normal', not everyone is homosexual.  Driving a car is 'normal' and not everyone drives a car.  What an odd thought process you have.

What I was alluding to was that if it is acceptable for siblings who cannot have offspring or who decide never to have offspring to enter into a relationship, that would 'normalise' that type of relationship and others would see that it was acceptable.

Eventually there would be siblings in relationships who did produce offspring, by accident or design, and that could then become 'normal'.

I know there are a lot of 'what ifs' in there but this discussion was started by someone playing devil's advocate and I am adding to it in the same vein.  I am not a biologist and do not purport to know what the full effect, if any, would be on the gene pool.

From what I have seen and read with regard to reproduction in the animal kingdom, incest does not seem that common, but I might be totally wrong there too (prepares to be flamed.)  This article is not definitive but is interesting reading non the less http://www.livescience.com/2226-incest-taboo-nature.html

But we want to preserve recessive genes. A world without blondes or redheads? No more cute freckled girls? We'd also lose blue, gray, and green eyes. Straight hair is the recessive gene. 

Strangely, (t)here are some dominant genes that do not often express themselves. Extra toes are dominant but are not common. Fingers that lack a joint, extra fingers, fused fingers and short fingers are also dominant. A straight thumb is dominant while a "hitchhiker's" thumb is recessive. A bent little finger illustrates a dominant gene, while a straight little finger characterizes a recessive one. (source)

"I have seen many people in Walmart who probably shouldn't be allowed to procreate with anyone,"

It seems to me that "natural selection" in humans is now favouring those too stupid to prevent pregnancy and those disinclined to form permanent relationships. I'd guess that, today, there is an inverse relationship between intelligence and number of offspring.


It took me four really big breaths to read all of that.

It also works if you read it like a rap song.

If you actually know a 12 year old who's having sex with a grown up (you said "I know 12 year olds who are having sex, some with older men") when are you going to report this outrage to the police?

Very good point. If that really is what the person meant, when the original text was:

"...this guy its right kids are having sex at younger ages i know 12year old's who are have sex and same with older men and that fact but that not a subject or the subject of rape or sex slave the fact that things are going on like that in this world just j really piss me off if i ever met a men who do any like rape or sex with kids i would not be able to stop myself from killing..."

Mate, you need a job.

If lifeimagex1 can express himself no better than that, he/she deserves to be ignored.

I'm almost 100% certain English isn't his first language. I'm sure he's doing far better in our language then I could do in his.


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