Having at the very least a basic understanding of psychology is critical to characterization.
A lot of attempts to “explain away” certain character traits fail miserably because the character’s writers don’t really understand how psychology works. *coughChristianGreycough*
Naturally, every individual’s past affects them in some way and influences the way they behave and the way they respond to events, situations, and people in the present. However, it’s not as cut-and-dried as people like to think.
The problem with a character like Christian Grey - besides the fact that he’s gross and abusive - is that his history and the conditioned response to his history really do not make sense. Putting the BDSM aspect of his character aside, do remember that Christian literally says that he likes BDSM because he wants to “punish girls that look like his mother”.
First of all - ew. Second of all, that’s not really how the human mind works. This approach to psychology (and characterization) is very Freudian at its core and, like most Freudian psychology, you can send it flying straight through the nearest window.
It’s not that there isn’t some basis for this kind of A + B = C understanding of psychological development. It’s that its a very, very dumbed down, simplistic approach that for obvious reasons rings very, very false in readers. Even if it’s only instinctual, most people know better than that.
A much better approach when considering how events from a character’s past would affect their reactions/personality/etc., in the present is to think about the patterns that developed in their life because of it, the habits that they developed because of it, and ultimately the way this character has learned to respond to certain stimuli.
Let’s say we have a character named Clarissa. Clarissa was raised in a single parent home with her father and her older sister. Her father was a caring, loving man, but was forced to work a lot, and because of that was rarely home. Her sister was verbally abusive and blamed Clarissa for a lot of the problems their family had - a lack of money, a lack of stability, and even the death of their mother.
Clarissa learns several things from these interactions:
When people become angry at her, she largely places the blame on herself. She also learns to expect people to become angry at her.
She learns patterns of avoidance on realizing that staying out of her sister’s way is the best way to avoid the verbal abuse.
She develops a pattern of thinking in which she fears causing trouble for other people, which leads her to avoid asking for help.
She doesn’t dislike authority figures (like her father) but largely considers them unreliable sources of aid.
However, if instead of avoiding her sister Clarissa had developed a more confrontational attitude and learned that, being the younger sibling, her father would take her side in these situations, the outcome could have been different. She may have instead learned that:
Confrontation is a way to get what you want out of a given situation.
Playing the victim is a way to turn opinion in her favor.
Authority figures can be manipulated into giving you assistance.
Clarissa #1 ends up being a very introverted, self-effacing individual. Clarissa #2 learns to play the “victim” to get what she wants. And Clarissa #3, who went to her father about the problem and had him step in to solve the issue between herself and her sister, learns to solve problems through open, honest dialogue. But how boring is that? (In fiction, anyway).
Think a little more critically about what your characters actually learned because of their past. You’re not just connecting the dots between past and present. When you develop a character’s personality, you’re weaving a tapestry based on the accumulation of everything they’ve been through and everything they’ve learned.