As a high school teacher, I see all kinds of kids, and (even though we shouldn't), I sometimes fall into the trap of lumping them into categories as an easy way to "identify" them.
For example, when someone tells me a child is an "AP Kid", I immediately form a general idea about their behavior and how hard they work. A kid who is "Chronically Absent" probably has low grades and is failing at least one subject. A student with a "Authority Issues" will, more than likely, give me a lot of trouble behaviorally.
But as much as people stereotype teenagers, I've learned over the years that these initial "identifiers" are not always reliable. The "AP Kid" might only be in the class because their parent wanted them to take it, and so is barely pulling a D. My "Chronically Absent" child might have a job which keeps them from the classroom, and though they miss a lot of class time, they always make up the work and are getting by. And the "Authority Issue" child might become one of my favorites. It has happened more than once.
So, I try to keep that in mind when I write YA Literature, because children don't like to be pegged or pigeon-holed any more than adults do. There is always more to them than what is one the surface.
If you write YA, I dare you to move away from the stereotype with at least one character. Try making them the hero sometime. You might be surprised by what happens.
Unique YA Characters - 1
Beth - 1 and counting