Using your logic, girls should be able to consent to sex with adults as soon as they begin to menstruate. Nature designed them for it, after all, right?
Girls aren’t boys. Girls are designed to psychologically and physically pair bond after sex, through the release of the hormone oxytocin.
This is a problem with girls, and women too, as they tend to aquire unhealthy attachment problems as they accumulate sexual partners, breaking (or losing) one attachment after another. There is research showing ongoing inability to pair bond the more sexual partners a woman has had. And IIRC its worse for women with an early age sexual experience.
Men on the other hand seem perfectly able to love them and leave them.
There are good reasons to think that human physiology is the underlying reason behind traditional sexual customs, which may have come about in a Burkean evolution.
Japan still has an age on consent law set at 13...
its societal law and well founded, but in my area anyway, girls were outcasted if they havent lost their virginity by 16 due to peer pressure. and once that happens, when they want it, they want it so there will always be these cases where consent laws are disregarded. I'll add... Rape, molestation is a whole different ballgame and the hammer should be dropped hard on violators...