Here is how I solved my problem:
Unlike channeled texts, that are transferred into the mind of the medium as a complete whole, creative writing usually begins with an idea and unfolds from there. Different stories grow from different seeds. Sometimes a writer has a scene in mind and develops the story around that scene: Who are the people in that scene? How are they related? What led them here and what happens to them now? Sometimes a writer has a character they find interesting and develop the story around that character: What would the life of such a person be like? Sometimes the initial idea is a relationship: What kind of people have such a relationship? How does it evolve? Will it last? Sometimes it is a world: Who lives there? What problems do they face and what culture evolves to deal with them? In my case the seed for my story was a plot, that is, a series of events, and I needed to develop my characters to fit that plot:
What kind of person would do these kind of things?
I had the series of events the characters would go through and even how this experience would change them. I knew, very roughly, a few rudimentary aspects of what kind of person they were at the beginning, and who they would turn into at the end. I had the basic form of their story arc.
The plot was thrilling, but to make the narrative interesting on the character level, too, I needed a "flaw" that my characters would have to overcome to succeed on their "quest", something that my readers could relate to and which would help them identify with the characters and care about their involvement with the plot.
- To find these missing aspects of their characters I tried to identify the key elements of their character arcs in clear and concise terms.
Using the example that I have used in my comments, of the detective who comes to understand and sympathize with the motives of the murderer, the key terms for this character arc might be something like these: At first, in the beginning of the story, the detective was focused on solving the case and bringing the murderer to justice. That is, he was law-abiding, principled, and correct. At the end, the detective had come to think that there was a good and valid reason for the murderer to kill his victim and he had to face the choice to bring him to justice regardless (upholding the law even when the law is wrong), or to let him go (and approve of and support the deed for some higher justice). That is, the detective had become sceptical, compassionate, and humane. I'm sure there are better terms to describe the personality states of that detective, and of course there are different personalities that fit the character arc. For example, at the beginning, instead of being overly correct, the detective could have been identifying with the victim, feeling affected by the victims fate, wanting revenge.
- With the key descriptors of what kind of person the character was and turned into, I then researched both the initial personality and this personality change.
Again using the example, I began to look into developmental and personality psychology to understand which persons are emotionally rigid and overly correct and law-abiding and what kind of experiences force these people to become more empathetic (or how victims come to understand and forgive perpetrators).
- Finally, I worked both this flaw and the motor for change that I had identified into the narrative.
In the detective story, I would have given the detective a background that explained his emotional rigidity (or victimization and vengefulness), making it a problem in his private life just as it was an asset in his profession. And I would have identified and expanded those aspects of the plot that could serve as catalyst for the detectives growth and help him overcome the self-limiting aspects of his personality.
There are some comments that insist that developing the characters after the fact is "unnatural", and that characters must "grow" and not be constructed.
This is wrong.
Of course developing the characters after the plot is a lot of work and it means that I have to rewrite much of my current draft. But rewriting is an integral part of writing. Tolstoy wrote the whole of War and Peace seven times. Hemingway wrote the end of A Farewell to Arms 47 times. So I'm in good company.
And doing research to find elements of a story does not mean that this will make my story (or my characters) "unnatural". Research is an integral part of writing, too. It would be unnatural if I just pasted what I found into my narrative. But if I process what I find, translating the results of my research into ideas, then they will either melt into the story, adapting to it, or the story will evolve to accomodate the new information.
All information that goes through my mind will harmonize with each other, because it will be turned into what makes me who I am. People are translators. They turn everything into their world view. So the research I do cannot disrupt what I have already written. It will become the nutrient from which my writing continues to grow.
But then maybe research is not – or not always – a means to find new information but rather an opportunity for self-reflection, and rewriting is not a forced process at all but rather a way to find out what feels most natural.
What surprised me was how seamlessly the results of my research fit into my existing plot. It was as if I had subconsciously known my characters all along and they had already guided me when I developed the plot, and I had only needed the research to help me become conscious of it.