I want to make my fictional characters well rounded individuals and not one dimensional. I want them to seem real. And the Internet is a great source for character building information.
Lynn Viehl provides helpful information in her article, Ten Things to Help with Developing Characterizations. She suggests you discover your character's horoscope, favorite colors, books he or she reads and (my favorite) what they purchase and make them a part of your character. When you discover this information, your character becomes a person.
But I have one more to add to the list in character discovery and that is birth order. Where does your character fall in birth order? Is your character firstborn and bossy (or is that just me)? Is she too serious? Is your character a middle child longing for attention? Or is he or she the clown of the family? Your character’s birth order may cause him to react with anger to being criticized. Your character may let others walk all over her because of her place in the birth order line.
I had some things to learn about my main character. She is an only child of an only child. Does that influence her to be self-centered? Does she long for companionship? Does she suffer from loneliness? Is she a persistent personality? And what happens between my main character and her mother if they were both only children. Is there conflict? My MC was bland until I considered her place (or birth order) in her family. Now she is much more interesting as I make her act and react to her birth order tendencies.
You can agree with birth order research or not, but it may help you to understand your character a little more.
Three online sources for birth order information are:
The Effects of Birth Order on Personality
Child Development Institute - Birth Order
Birth Order: Your key to Compatibility
Where do you fall in the birth order chain? Or if you're working on a character, where does he or she fall in that order?
Sources: Paperback Writer, Lynn Viehl, Wikipedia