A commenter writes, "Abortion rights advocates declare any [pregnant] female is mature enough to obtain an abortion without parental consent. That means girls are mature enough to make [decisions] in picking sex partners."

I don't think this works. Judgments about age cutoffs for various behavior (driving, sex, smoking, alcohol consumption, abortion, other medical procedures, contracting) rightly turn on a variety of factors, including the cost of prohibiting the behavior as well as the cost of immature behavior. We let people drive before we let them drink because not being able to drive imposes a much greater burden on older teenagers (and on their parents and prospective employers and educators) than does not being able to drink. Likewise, stopping a girl from having an abortion could harm her future life much more than stopping a girl from having sex would.

Now of course one could argue that letting girls have abortions without parental consent harms their future lives, too, or that it violates their parents' rights or whatever else. My point is simply that one can't just assume that the age cutoffs for the decision to have an abortion must be the same as the age cutoffs for sex, drinking, smoking, driving, or contracting. It's true that the age cutoffs for all of these do have to do with our judgment about maturity — but they also have to do with other matters that may justify different age cutoffs for different behaviors.

(Note that the current federal constitutional rule is that state law may require underage girls to get parental consent for abortion, though it must provide the option of a judicial bypass on the grounds that "the young woman is mature and capable of giving informed consent and has, in fact, given her informed consent" or "that an abortion would be in her best interests." But some state constitutional rules give broader abortion rights to underage girls, and, as the commenter suggests, some abortion rights advocates do support such broad rights for girls.)