Oh no, it's English 10 all over again.
I agree with the being born blank thing, but ZL, a mother smoking or drinking during pregnancy would still fall under nurture. Nature suggests that personality traits are somehow related to genes your born with.
But nature does play a part. It's hard to deny that if you take into consideration disorders and all that people can be born with.
I saw this book originally on The Colbert Report, I believe, and added it to my list of stuff to read but have yet to get to it:
http://en.wikipedia.org/wiki/The_Blank_SlateIt sounds pretty interesting.