There are no polarities when it comes to twins. No "good" one vs. "bad one;" no angelic child versus evil spawn, no duelling forces, vying for the top spot in their respective categories. There are just kids, warts, scabbed knees and all. Though the mythology and expectation of opposite-minded twin siblings is appealing to some, it is, fortunately, untrue.
You do not always get along. Sam told me approximately 44 times this morning that P.J. popped her green balloon. P.J. sometimes resorts to creating Mega-bloks jail cells to contain Sam. Alex pulls Sam's hair. Sam pulls back. But you get more pure joy from each other than you get from water balloons, McDonald's fries and the iPad combined. Which is saying a lot.