In high school I noticed that the boys were mostly attracted to the girls that looked older and I don't mean they have developed bodies. They were more attracted to the girls that looked "hot" but not "cute" girls with a babyish younger looking face. I don't know if I make sense?
Teenage boys are hormone fuelled machines who are attracted to anything haha, maybe they're unknowingly looking for a mother type or just trying to score high with hot girls cause you know...why wouldn't you? They're trying to become grown up, they don't want girls who look like kids, they want women.
I like the older girls better because they are more mature. The younger girls act like, well, girls. They're extremely bubbley, they don't know when to stop screwing around, and they are hard to take seriously. The older girls dress respectably, now how to act, are responsible, and can be taken seriously.