And even if they arent in high school, they will generally still be teenagers. And this is the case even if the teenagers are performing roles you would expect of a an adult. For example, in Code Geass, Lelouch is the leader of a paramilitary terrorist organization even though he is only in high school. The same goes with Kaiba in Yu-Gi-Oh. Who is a CEO of a multi billion dollar company even though he is still in high school. Scientifically speaking, what is the reason for this?