@mujus: you said 'You have a very odd notion of "human function."'

Humans eat, fuck and fight. Mediated by culture.

These are social level functions above the mechanics of digestion, breathing, and muscle use.

It is not hard to avoid fghting (for most adults, though some kids struggle) society mediates that behaviour.
Sex is held up as this amazing thing which you can't have, used to sell products and banned in public places... Somehow everywhere and nowhere. Teens go through rebellious phases regardless (something to do with leaving the nest, they have become physically capable of surviving on their own; out society is more comppex emotionally and economically, which leads to trouble) but they still compete with each other for status, and sex is a great option for them.

Religion tries to mediate this. While when it comes to violence their peers are mediating the behaviour. It is undesirable to all. (when it comes to food we eat without much thought, by and large, to any consequences beyond our own health, convienance and pleasure/flavour enjoyment - that is beyond our egos)

Society mediates human behaviour, always has, whether it was parents showing offspring what food to eat, or how to fish (the best source of hunted protien for 'hunter gatherers' was fish)

Society mediates when it is ok to be violent, and how - American football, boxing, fencing... there are many acceptable forms of violent sports in our society. And different subcltures have different standards - prisons tend toward violent competition, poor urban neighbourhoods where teens can't compete for jobs, income, political status or academic achievement tend to end up more violent (this acts as a survival trait, scaring off potential threats by being threatening, at least for male teens, femape teens tend to see a spike in their pregnancy rates rather than violence rates, again survival is being guarenteed by reproducing)

So yes, all normal things, all mediated by culture. But this is a question of public p

Public policy. As in the official government part rather than the huge amount of private influence which corporations (who are people afterall) have on our culture.

Massive outcries may get comedians who tell rape jokes fired. But by and large pulic outcries are a minor influence on corporations, especially where being outrageous can be a good advertising tactic. Yet we presume humans have the power to decide for themselves, that free will reigns supreme - it does not, we are heavily influenced by our culture, or even counter-cultures or hippie/vegan/organic foods... - we have public policy for the common good. We assume that we can't survive in a purely free market corporate society - so no privatised military, no private courts, and government attempts to remain independant... While attempting to please their electorate... Maybe judges appointed for life would make a better system of government.

But i digress. Education is for the public good. Religion is relegated to a private interest (with tax free corporations, selling salvation* in exchangd for mediating the behaviour of their customers) - At least in America.

Individuals are free to choose which religion the adhere to, or none. Equally religions (which may be closer to being people than corporations) should have a say in public policy. But it should be determined by the results which are desired.

If we want to influence teens propensity to have sex we need to alter our cultural worship of sex. That happens to be in private hands already, so isn't a question of piblic policy (similarily the warrior culture in the US - hero worshipping 'the troops', sports stars and gun use, is a contributing factor to the violence in US society, and i'm sure varies from state to state... ) What public policy can do is empower people to make their own decisions to prevent disease - abstinance is a great prevention tool, however teaching abstinance only sex ed results in teens having sex anyway, the evidence is that combined approaches are better.

So back to parents and opt-outs. A minimum standard of health education would include explaining how disease can be past from person to person by the sharing of bodily fluids, and that this is necessary for reproduction. (and kissing) this kind of info should not have any opt-out in my opinion.

On the otherhand, giving parents information so they can easily home school their kids would be a great boon; i'm all in favour of adults learning something from the education system to a level where they can teach it.

Regarding the more graphic extreme of sex ed, i think it is better in schools (even with an opt-out) than learning from pornography - which is in private hands and tends to be rather misogynistic and distant from reality (sorry for the break in the post)