nature or nurture

I am certain that Joshua Chavira is the SWEETEST boy in the world. Don't get me wrong, he can act his age, but not often and not crazy bad. In all honesty, when he does act up at school, he will always test positive for Strep! Pediatrician says the same thing about her daughter. I thought we were crazy for thinking that. BUT ANYWAY, I would like to hear from my friends that have more than one child and can see the personality differences, what do you think? Is the "sweet factor" nature or nurture or a little of both? So far Cici has shaped up to be a little more high maintenance than we remember Josh being at her age. She is much more animated and dare I say...dramatic.. UGH, I just hate that I had to say that. She is so far not the docile creature that Josh is/was. Please dont misunderstand, I am ok with that. I am not complaining. She is so funny and so much fun. Just curious. I can't imagine that we would be lucky enough to get to children as sweet as Joshua. She can sure dole out some good drooly open mouth kisses! those are the best!!