[on a 10 year old child giving birth in mexico]
If you think 10 year olds are too young, you really shouldn't look at human history.
There's a reason for the remark "if she bleeds, she breeds". Back in the day, before penicillin, infant mortality rate was really high. In addition, you needed kids help to work the farm and whatever. The only way to accomplish a lot of things it to breed as fast as possible. This included what we define as kids.
The big deal for us is 10 year old's have no method to survive on their own. We deem them irresponsible and incapable of making live changing decisions. We believe at 18, you're smart enough for live changing decisions (excluding alcohol, being the President, a member of Congress, etc). From others perceptions about it, they look at us as we're going out of our way to teach children (<18 yo) that they can not be responsible until this magic number 18 hits them. In Texas, it's 17, btw, with a 3 year Romeo and Juliet clause.
I think far too often people forget we are still slaves to our biological masters. We're horny because our body says "MAKE BABY NOW!". There are 13 year old that look like 18 AND get in to bars with a fake ID. They are horny like anyone else but are held to a different standard. Right, wrong, or indifferent -- that's the way it is and it'll be a political war to change it. The war won't be able what's best for the children or adults. It'll be what looks best and will help assist in voting people in to power.
In the US, sex is a scary thing. Showing vag in a movie will get you an X rating. But showing someone losing their torso and blood everywhere may still net you a PG-13 or maybe an R. Sex is natural and something your body really likes. Killing, not so much. Personally, I find us as backwards