sadlife reminds me that I didn't respond to this. It is indeed entirely polite and reasonable (thanks).

witness the difference in outcomes for rape victims from cultures where extramarital sex is widely condemned as opposed to cultures where extramarital sex is broadly accepted

Do we have references on that? I'm not saying that with any particular axe to grind, I just hadn't seen any studies on it or specific claims about it.

In cases where abuse is disputed iatrogenic and sociogenic factors are clearly even greater causes of harm, and it seems fair to say it is the primary cause of harm - though of course it is difficult if not impossible to make empirical claims about emotional harm.

There are some studies suggesting that victims of violent rape or child sex abuse have better psychological adjustment than ones where they apparently consented. I think "A Natural History of Rape" made that case for adults, and perhaps Susan Clancy did for child victims? (And for adults there's an intriguing evo psych hypothesis).

I agree that iatrogenic/sociogenic harm is a big part of the apparently consensual cases, though I don't think it is all. I think betrayal of trust can play a big part, and betrayal of implicit expectations.

I wonder why you did not distinguish actual from imagined abuse, as we usually do here.

We all seem united in thinking that sexual activity if it's lacking even apparent consent is wrong. It's wrong whether you can prove harm or not, and that's worth thinking about a little bit. So most of the cases of interest are ones where a child apparently consented.

As for why we should not presume that most people mean "informed consent" when they say "consent" - there are two good reasons. First, most people haven't even thought about the distinction

You can make useful inferences about people's beliefs even if they haven't thought them through already. I'm quite sure that if you ask most people if kids above the age of 5 (or 2, for that matter) can say "yes" or "no" about a proposed activity to the extent they understand it, they will say the kids can.

For some reason, this line from "Home on the Range" always makes me smile: "The skies are not cloudy all day." The way I understand English grammar, the preferred interpretation is that the sun comes out for at least a little while each day. But of course it means that on most days (?), there are no clouds at all. People may not have thought about the ambiguity before, but we can make good guesses of what they'll say it means if you point it out to them, and therefore what they believed all along.

no one of any age can foresee all future consequences of their actions - making informed consent impossible for anyone who has not already lived forever.

I saw this whiz by in some other thread but didn't respond to it then. This is a cop out. By analogy, no activity is totally safe, so we should not worry about some being more dangerous than others?

There are degrees of being informed. This is obviously very intricate and contentious when it comes to stock prospectuses, reports coming out of publicly traded companies, and insider trading.

There are degrees of being informed about sex, too. Unable to draw fine distinctions about informedness for every individual case, the law draws a big arbitrary line based on age. At some point you know a great deal more than you did before, and it's enough to make a big difference. So argue about when kids know enough, but saying there's no such thing as informed consent isn't good thinking.