Sometimes the differences between shallow characters seem extensive—“he had abusive parents and no siblings, she had twelve siblings and an idyllic upbringing”—until they open their mouths, and then they start to sound exactly the same. In this post, I’m going to address why I believe this happens, and some possible solutions.
Before I jump in, I want to explain why this turns me off as both a reader and a writer. The example that comes to mind is a series I was reading in which every single character (there were four viewpoint characters) reacted in the exact same way to events that were happening, despite completely different backgrounds. It threw me out of the story, since I just couldn’t believe that characters could behave so similarly—as the name suggests, the believability of characters and their actions are essential to character-driven novels.
The key problem lies with history and personality. History is a character’s backstory, what I just gave in the section between those two dashes, but personality consists of the character traits that result from that history. When an author has a fully fleshed-out history for characters, but their personalities only seem superficially different, it tends to result in those superficial difference. I believe the problem occurs because they fail to take the last crucial step: determining the kind of personality a character’s history would create.
For example, people with dark pasts are rarely bright and sunny, and people with easier lives tend not to be cruel except by accident. If I create a character whose backstory involves siblings, the immediate next question is how that affects them. Did they like their brothers and sisters? Are they the oldest child? Was there a difference between how they were raised relative to their siblings?
The absence of these questions is what tends to result in superficial differences. If only history is considered, and that crucial final step isn’t taken, an author will default to writing themselves into situations, and—unless that author has a schizotypal disorder—the resulting writing will contain homogenous characters.
So, after you have a character and their backstory, ask yourself some questions about how that backstory affects their personality. And don’t be afraid to go too far; an overly mean and aggressive character is easier for readers to swallow than a milquetoast.