E.T.
There is no right answer. Whether to keep twins together or separate is one of the biggest questions on the twinboard I read. Some people swear by keeping their kids together and some are certain separate is the way to go. For my family... I kept my girls together in kindergarten and I mostly think it was the right choice. My girls compared themselves more than I would have liked, but everything else was good. One of my daughters was pretty certain she didn't want to be in the same class as her sister, so this year in first grade I separated them. Once again, I mostly think it was the right choice. They do miss each other but they're happy and learning and making their own friends which is cool-- and the teachers they have match their personalities.