AceShowbiz - Natalie Portman rules out ever playing a serial killer. The 42-year-old actress - who took home an Oscar for her outstanding performance in now-husband Darren Aronofsky's psychological horror "Black Swan" - tries her best not to take her work home with her.

"I don't do things that are painful. I can't starve myself for a role; I can't cause myself pain. I'm the opposite of that. I get acupuncture, I go swimming. I like to cook," she told Radio Times magazine.

"I like hanging out with my friends! When I'm not working, I need those days where I just stare at the wall for a few hours and refresh by doing absolutely nothing. I can relax, but when I work, I want to do the best job."

The "May December" star also has no time for anyone being "unkind" on a film set. She continued, "There's a discipline to being a good person while you're working. If there's someone being unkind on set, it takes me out of my focus. I have no patience for that. So that's part of the discipline, too. Being kind and kind. To see directors who do that - because there is a great deal of stress - is remarkable."

Asked if she would ever consider method acting, where the actor emphasises on a deeply emotional level with the characters they are playing, Natalie replied, "If you did, I don't understand how you would play a serial killer! It's inevitable you'd take something home with you ... that's not even a choice."

"That's why you have to be careful about what kind of roles you choose, because it affects you definitely, but I just don't really understand the idea of becoming your character. That would get rid of half the characters you could play, because it would be illegal!"