Having grown up in a house with 6 sisters, you would think that I (especially as the oldest of the seven) would inherently know how to discourage sisterly bickering. I don't.
My sweet girls are small. Four and two years old. And they are at odds about almost everything these days. They both have decisive personalities, each wanting to do what she wants to do. (There is no bowing of the younger to the older, if you know what I mean.) And it causes problems when there isn't a consensus about what movie to watch, which game to play, how to play it, what CD to put on.... It doesn't make things easier that the older one is becoming a master of annoyance and provocation and the younger one is a hair-pulling expert.
I have a theory that among other things, our move across the country, coupled with the arrival of a new baby brother, has triggered the need to have as much control as possible. When you're that little, there aren't many things you can have control over. So what do you do?
The baby brother is no fun, because he can't really do stuff on his own and mom is always hovering around him anyway. Parents are so big and it's tough to move them around exactly how you'd like, so who's left? Well, there is the girl standing next to you, almost your size, and usually a willing accomplice, at least for awhile, anyway.
We're going through a phase. At least I hope so. The bickering and screaming upstairs can be stopped. It requires the threat of separation, and then the girls immediately unite against their divider. Go away, Mom. We're having a good time, even if you aren't.