Author’s Commentary #06: Chaz’s Origins
Chaz Greene was originally created for Caleb's character when our smaller twin was in need of psychological companionship. He was a psychology student, at the time who rejected all of the established social norms.
Originally in this story, Caleb was fairly dangerous (even more so than he is now) and therefore needed someone who was not only able to handle possible threats but could also empathize with the possible violence and a distorted view of the world— giving Chaz his anger issues.
However, Caleb was also in need of someone that could fight the apathy that he had for living at the time, and a sunny, upbeat and beachy personality was added to the character.
Later on, Chaz was modified and polished. We realized that it wasn't necessary for him to be a student of psychology, as his past experiences and own intelligence sufficed.
Brad Pitt was chosen for the role, as Caleb needed someone he would not only feel protected with, but also wouldn't represent a true threat. Brad's 'pretty boy' features combined with such a muscular physique seemed a perfect choice. His smile sealed it.