Re: Why is 18 improbably old?
@AC - Emotional maturity doesn't magically happen at a certain age or at the same age for everyone. Trying to tie the legal age to something like that is pointless.
So why have a limit at all?
@AC - The legal age is to protect against exploitation not teenage regrets.
Actually it's there for protection of all sorts, not just exploitation. Teenage regrets are nothing compared with unplanned children in an unstable (or non existent) family.
The limit is in place because there are consequences which cannot be reasonably accounted for by most teenagers - and we really ought to be protecting the less able teenagers. Sex isn't something that is required for life to continue, there is no significant detriment to having teenagers wait (I know of no-one who has regretted waiting).