The character he plays is a whole lot like that, too. For the most part, this does't effect the game he's in, but now and then this isn't so great for him or the people he plays with. Recently, something pretty unpleasant happened to his character, and his response was - mild. He just couldn't bring himself to do something "different" from his normal self, something crazy, foolish or even outraged.
It was very rough for me to witness as a bystander. I was furious and wanted him to "do something". However, that really isn't in his personal character, and he couldn't reach enough past his own makeup to act in line with another personna.
At first I was very critical of this, and then realized that I am guilty of it too. I was specifically challenged to run a particular type of character recently, and I balked- HARD. I just wasn't comfortable with the things I would need to do in that kind of role, and felt it wasn't a good fit for me. I did move away from the kind of character I traditionally run, but I certainly did not do any real "break away" stuff in designing my new dude.
If roleplaying is all about being someone else and exploring parts of yourself, these boundaries make it difficult to achieve something greater- and it's doubly hard when you don't know you're limited. I sure didn't- at least not until I looked closely at the situation.
How do you break out of your own self and into someone else; move beyond your own personal tendencies and into new territory?