Here’s another way to generate character ideas. Substitute one reaction for another. We all tend to make our characters behave like ourselves or like people we know. So let’s say I’m a computer geek who tends to be shy and reserved, except when I’m talking about computers. Then I’m talkative and outgoing. They say, write what you know. And if I can work these feelings into my character, the character will be more realistic. If I want a character who is different than me, I can feel these same reactions, but apply them in different situations.
For example, I could create a character who is passionate about horticulture or some other subject. He’s quiet and reserved, but ask him about plants and suddenly he’s a fountain of knowledge and amusing anecdotes of our green leafy friends.
Or I could create a character who is generally outgoing by drawing on my own outgoing side and by looking to people I know who are also outgoing. Think of the behaviors they exhibit. But this character has a different background, different passions, different fears, different needs than either I or my friends. She will behave differently than us in the same situations, and she’ll behave the same in different situations.
There are only a few different ways we respond to the world around us. But we each respond differently, with a different mix of these ways, depending on the context. There are only a few character reactions. And a character reaction only becomes a characteristic in a situation. By supplanting reactions and situations, you can produce different characters, each of which is a completely realistic new personality.