Judging by the way most people react to how much gender affects punishments, "superiority" tends to play a part. If a guy is given more jail time for sleeping with someone under-age who is a  girl then if it's the opposite case then obviously it should be equal jail time - it's the exact same crime.

As for chemical development, that's only in regards to the average person. It's referential to humanity as a whole, which is irrelevant when we're talking about specific things as we're narrowing it down.