On developmental psychology...

[Harlan]

So even if they understood the consequences of sex...

If we are talking about safe sex without coercion and rape, then the only consequences can be hypothetical infections, with heterosexual sex pregnancy is also added. These things are not inevitable and life threatening. All this can be prevented by proper sex education and a sex-positive culture.

Please forgive me for repeating myself. Children who have learned to walk and ride a bicycle are taught the traffic rules. Agree that the threat to life on the road is higher than during sex, but despite this, minors are not prohibited from riding bicycles until they are 16-18 years old. Teach them to use condoms and distribute it among young people without shame and fear and they will use them. This is the only way to prevent accidental pregnancy and infections without disrupting the natural sexual development of young people.

parent-child incest is generally so traumatic...

The same, if we are talking about voluntary sex without coercion and rape, then the sex itself will not be traumatic. Putting a stigma on sex artificially turns this experience into a traumatic one.

[PorcelainLark]

So even if they understood the consequences of sex...

If we are talking about safe sex without coercion and rape, then the only consequences can be hypothetical infections, with heterosexual sex pregnancy is also added. These things are not inevitable and life threatening. All this can be prevented by proper sex education and a sex-positive culture.

Please forgive me for repeating myself. Children who have learned to walk and ride a bicycle are taught the traffic rules. Agree that the threat to life on the road is higher than during sex, but despite this, minors are not prohibited from riding bicycles until they are 16-18 years old. Teach them to use condoms and distribute it among young people without shame and fear and they will use them. This is the only way to prevent accidental pregnancy and infections without disrupting the natural sexual development of young people.

I think I agree with this.

parent-child incest is generally so traumatic...

The same, if we are talking about voluntary sex without coercion and rape, then the sex itself will not be traumatic. Putting a stigma on sex artificially turns this experience into a traumatic one.

I'm not sure that the stigma on sex can be changed so easily. My theory is that it has to do with bodily functions generally. As an infant grows up, they learn to distant themselves from their excrement (why for example "bed-wetter" is strong insult amongst children). These boundaries about the bodily functions, mean that sex is shocking (i.e. because it's dirty, it involves the groin). It's hard to change sexual norms for much the same way Western-style toilets aren't substituted for Japanese-style toilets, even though the latter could be seen as less wasteful and more hygienic. The regulations of the body are the deepest ingrained norms in any culture. The parent serves the role disciplining the body, and ingraining what is and isn't disgusting.