"And in one sense, no matter whom they're based on, every character you  create will be yourself. Even if you've never killed anyone, your murderer's rage will be drawn from memories of your own most extreme anger. Our characters' emotions draw on our own emotions. Until telepathy is common, our own emotions are the only ones we've intimately experienced. They're our default setting, and you can't help but incorporate them inside other characters' heads -- no matter where those other characters come from." Nancy Kress (March 2004 - Writer's Digest).