I have yet to prove my thery but we will see...
My DD was crazy in my womb, always kicking, always moving. I think she actually got "pissed" when she'd get the hiccups (she got them alot). She move around all crazy and start punching me like she was upset. I always thought, "She's going to be a little spitfire." Yeah. She pretty much is. She's always running around, always climbing on things. Girls are calmer? Hmmm....not mine!
I'm carrying a boy right now. His movement are gentle and fluid. I feel him move, but it's not the attitude filled movements like my daughter had. I get a sense of calm and peace about him. I'm thinking he will be my calm and laid back kid. I have yet to prove it of course.
It's ALL about personality!!!