They aren't all the same, of course, but here's a basic overview: -Little girls are magical princesses, just ask them. Through the age of maybe eight-years-old or so, girls are frequently vain and convinced that whatever hunky guy they pick is going to fall madly in love with them, and they're going to be movie stars, and they're going to save the world. Big hopes, big dreams, and big attitudes. -Tween girls, around thirteen-years-old, are sometimes still vain, whatever the hot guy of the day is still wants to marry them, and they're usually going to be a movie star, singing idol, or a supermodel. Some are still vain, but others start to get insecure and don't feel good about themselves any more. This is when a lot of girls start to act very fake: they pretend to like people they don't really like, they gossip about other people and spread rumors, and they start wearing make-up. Others start turning into real people: they figure out what kinds of music and movies they like, which sports they may like, how to interact with people like a grown-up. -Teenage girls run a broad spectrum: some are still in love with themselves, some are still pretending to be what they think people want them to be, some are overconfident, some have no self-confidence at all. More of them are starting to act and interact like grown-ups, figuring out what kind of jobs they really want, how to get to those jobs, taking care of themselves with less help from their parents, learning what kinds of people they really do want to date, and stuff like that. Lots of them are still acting like tweens, however, and are not much fun to be around. Hope this helps!