The most alive characters in fiction, the most realistic, are true to themselves – They are not there to do your bidding as their writer and creator – They are not there to follow your orders or to show the world your feeling or thoughts or ideas – They are not there to obey you – They are there purely as themselves, reacting as they would react, thinking and living and breathing inside their world – not yours.
This is something I have learned. It might not be true for every writer (you all know your own style and what works for you), but it sure is true for me.
Some writers find character development tricky – how do they flesh them out? Personally, I don’t try to flesh them out, I let them flesh themselves out because then it’s the reflections of circumstances that’s doing it, not choice.
It’s too easy to try and control your characters. You created them to say something but you cannot force them to say it. They are not dolls or puppets, no matter how much you want them to be. Yes, you can treat them as such, force them to comply and have it all your way, but I guarantee that all your readers will see is awkwardness.
If you want something said or done, you must create the circumstances that will allow a character to develop into the sort of person who would want to say or do it.