Some 13-yr-olds have enough judgment. Some 16-yr-olds haven't. So what? Make them all wait till 18? or 25? Or 40? When I say age of consent is a man-made construct, I mean it is going to be arbitrary one-size-fits-all whatever age you choose unless you make the lower limit an absurdity. The menarche, before the law came interfering, was generally regarded as nature's way of making the judgment — even if mental development doesn't always keep up with physical, the attempt to establish hard & fast rules is going to be flouted by those whose bodies tell them so. I refer back to Romeo&Juliet again...