Many methods are used for personnel selection but handwriting analysis is proven by use.
A handwriting analysis of your signature reveals your self-esteem, your relationship with your Mother and Father... and even your relationship with your spouse if you're married. To the trained eye, a signature reveals a great deal about the writer... things such as self esteem and how the writer feels about their father and that side of the family. It can also indicate whether or not they're open and accessible to others... or if they really prefer a fence between them and the rest of the world.
I wonder if it's a really good idea to teach handwriting analysis to teachers. That way, we can raise an entire generation of optimists!