As a professor of creative writing and also the facilitator of many workshops, I have learned that sometimes the problem with a story is a personal problem, not a writerly problem. For example, a person who relies too heavily on dialogue-- that's a writerly problem. The same for overuse of adverbs. But often when the characters are stiff and undeveloped, that can indicate a personal problem.
By a personal problem, I mean that the issue is rooted in the writer's way of moving through the world. There are many personality quirks that can spoil the writing, but today, I want to talk about empathy, or a lack thereof.
Writers are often motivated by something/someone that angers, irritates, or appalls them. Some people write to get even with a person who has hurt them, or to expose some sort of destructive force in their community. These subjects could be anything from the mean girl who picked on you when you were ten to the evil dude that owns a payday loan company on the corner. What about crusades against "gold diggers." And so on. If your story is going to be any good, you are going to have to get past this.
This is going to sound crazy, but I can sometimes tell from conversation with a writer whether she is going to have this problem with her work. If conversations often begin with "I just don't see why she did that..." Or, "Any fool could tell that wasn't going to work..." Almost any sentence about another person that begins with "I just can't understand..." exposes the sort of emotional flatness that may show up in the work.
So how to break through?
One thing I like to do is to write journal entries in the voices of other people, or even characters in my books. I sometimes do it for people who have hurt me deeply, so I can kind of get a grip on their behavior. The challenge is that you have to discover something new about the person or character. If your exercise reveals only what you came to the page with in the first place, then you have not tapped into the empathy you are going to need to write the story you want to write. The thing is that you are really going to have to want to understand that person, which means you may have to let go of that anger.
In my new novel, The Silver Girl, one of the major characters is James, who has a secret family. You can imagine the pain this causes everyone else in the story. Still, I had get next to James and really see his side of things.
One of the tricks I employed was to look at what he was doing, and think how it could have been worse. So: in the novel he has a secret daughter whom he sees only once a week, but he pays bills, and constantly lets her know that she is just his #2 daughter. So then I said, well, it would be even worse if he was not in his daughter's life, denied paternity, did not support her in anyway. Okay, once I had that together, I asked myself, why didn't he do the really ugly thing? Then, I tapped into the part of him that was trying to adhere to some sort of moral code, the part of him that had an understanding of responsibility and family. When I came to that, he stopped being a cardboard cut-out and became flesh.