Natalie Portman: How studying psychology helped her in her latest role

She's petite and seemingly fragile, but appearances can be deceptive. Natalie Portman, at 24 years old, has been a professional actress for more than half her life. With 18 films to her name plus a degree in psychology, she's a formidably smart young woman.

Having performed promotional duties for all three films of the second Star Wars trilogy, she is media savvy, which is just as well given that her new film, V for Vendetta, has plunged her into murky political waters, where one man's freedom fighter may be perceived as another man's suicide bomber.

"I don't think there's a message about terrorism in the film. It creates a complicated story and I think it's all about what the audience brings to it," insists the Jerusalem-born actress who plays Evey, a young woman rescued from gang-rapists by V, whose disfigured face is concealed beneath a curiously creepy Guy Fawkes mask. Set against the futuristic landscape of a totalitarian Britain, the pair become unlikely allies in a battle against tyranny.

"Even though the film is set in this specific place and time, it is an imaginary futuristic place and time. And because of that you can make whatever connections you want to different things," says Portman. "Some people have seen this movie and are like: 'Oh, it's like Hitler's government, someone rising against that' and that sort of universal thing that we'd all agree with."

After three Star Wars outings, Portman was more than eager to tackle V for Vendetta - exchanging Queen Amidala's painstaking three-hour hair-and-make-up routine and clunky dialogue for a shaved head and an exhilarating sense of personal rebellion.

"I literally begged for this part. I flew out to San Francisco and read for the role. And thank God I got it," she says earnestly. "I just think its so rare to find a movie that's really entertaining and really fun on a big scale and on an impressive visual scale, that's also really so interesting and is going to give you something to think about afterwards. I've not seen a movie like this - that's this big and this interesting - in at least the past 20 years. Not since the Sixties and Seventies has there been some evidence of a big studio movie being compelling and visually exciting, entertaining, smart and interesting and something you could fight about afterwards. Big, big Hollywood movies have been disappointing until this. James McTeigue and the Wachowskis have made something incredible," she says, referring to V for Vendetta's notoriously elusive screenwriters Andy and Larry Wachowski, who were also responsible for the $3bn-grossing Matrix franchise.

Illustrated by David Lloyd and written by Alan Moore, the graphic novel V for Vendetta was conceived in the 1980s amid an era of oppressive Thatcherism. The villain of the piece is John Hurt's Hitler-esque British chancellor, who could just as much be President Bush or Tony Blair. But press Portman to name the enemy, and she demurs: "I'd rather not say. Obviously I have my own version of who the obvious candidates are but it's amazing hearing peoples' different reactions as to who the targets are. I sat with someone yesterday who literally had a framed picture of Bush on the wall of his office here in Los Angeles and was saying how much he loved the movie and how he thought it was the greatest anti-fascism movie ever, whereas other people see it as a completely anti-Bush thing. It's funny because you interpret it according to your own beliefs.

"What was really amazing about making this film, and I think it speaks so much for the British Government, is that they allowed shooting at Whitehall," she says, adjusting her rigid body language as she relaxes into her stride, hauling both stiletto-sandalled feet onto the expensive pastel upholstery of a Beverly Hills Hotel sofa where she perches, cross-legged.

The daughter of the Israeli fertility specialist Avner Hershlag and the American artist Shelley Hershlag, Portman enjoyed a relatively normal upbringing, growing up in suburban Syosset, New York, and adopting her grandmother's maiden name to protect her family's identity.

But now, as one of a handful of Hollywood's openly political Jewish actors, she has no problem debating terrorism, having studied 'the anthropology of violence' in graduate school.

"Being Israeli has become a much bigger part of my identity in recent years because it's become an issue of survival," says the actress. "I am personally sort of a pacifist and I am against violence. My gut feeling is that hurting other people is wrong, whether or not it is state-sanctioned. It's all violence and I don't make distinctions. All violence is wrong in my mind. I don't like it but I also know that it's sort of the way the world is. My reason sort of goes against my idealism and my optimism about the potential of people to live without violence and obviously people saying, 'oh it's natural for people to be violent'. So obviously I understand why it exists, but personally that is my stand and it's very hard for me to agree with any sort of violence."

She recalled the sufferings of her grandparents during the Holocaust when she filmed V for Vendetta's concentration-camp-style torture scenes. "Fortunately my grandparents escaped, but their whole family perished in the Holocaust," she explains. "There were stories in the house of what had happened to them and it wasn't that much talked about. I had to go on a website to read my grandfather's descriptions of what happened to the family, but it is absolutely something I have lived with and have grown up with.

"I loved that this film is an abstract thing because, after the Holocaust, people said it would never happen again but now we have Rwanda and Bosnia. Maybe V for Vendetta can remind us to stand up against such despotism."

Portman was discovered in a New York pizza-parlour, aged 11, and made her film debut in 1994's Leon, opposite Jean Reno. "I had a bad experience when Leon first came out," recalls the actress. "In hindsight I'm really proud of that film though at the time it was unnerving to find myself being suddenly looked upon as a sexual object when I was still only 12."

Then, having featured in an eclectic array of films, from the mega-budget Star Wars to independent films like Free Zone and Garden State, she risked her career by taking time out to study. "I'm going to college," she said at the time. "I don't care if it ruins my career. I'd rather be smart than a movie star."

Today she has no regrets about her four years at Harvard followed by a further year's Hebrew and film studies in Jerusalem. "My parents have always stressed education over success, over money, over everything," she says, "and I think college was great in terms of how it has made me want my career to be as interesting as school. And with fascinating material like this, its all about finding the questions that don't have answers.

"I don't want to ever be working just for money because then you are no different than a prostitute," says Portman, who not only shaved off her hair for V for Vendetta but also voraciously researched her role despite the fact it is a work of fiction. "I read Antonia Fraser's book. It's a great background to the whole Guy Fawkes story - which is not even really the Guy Fawkes story, like there were several other people involved and Guy Fawkes was the first one caught, becoming the poster boy! I also looked at lots of other things like Menachem Begin's book, White Knights, plus Macbeth!

"But don't get me wrong," she grins, suddenly self-conscious that she's sounding like the school swot. "I don't want to have a super-snobby intellectual career. I have the most amazing friends in the world who are doing such interesting and different things, and are their own people, and are my complete base of support along with my parents. They are inspiring and always doing different, interesting things so I remember how to be a person by being around them.

"Like, you can play a person if you are a person in real life. Its hard to be like, 'I just pretend to be a human being on TV!' So the most important thing about college is that now I really have a life and I've got that forever," she says.

Portman recently completed work on Milos Forman's costume drama Goya's Ghosts with Javier Bardem and Stellan Skarsgard, and Paris, je t'aime with Juliette Binoche, Willem Dafoe and Marianne Faithfull.

"I use my psychology background all the time," she admits. "I could use it to mess with people but that would be a mean thing to do! Actually I don't think I know enough to really mess with people but there's always studies that I've read or something I've read in college that I'll remember when I'm reading a script about a certain disorder, like 'this person might be a little bipolar or associative', those kinds of things.

"I just finished Goya's Ghosts in Spain, and my character had this disorder and I was able to call up one of my professors and she just gave me a whole run-down on symptomology and videos and examples of what the person might behave like. Its a great resource to have, these great professors," says the actress.

Her idea of fun is spending months with a voice-coach, so that in V for Vendetta she sounds almost more British than her Phantom Menace friend and co-star Keira Knightley. "I had a great coach who worked with me every day for a month before the film began and then she was with me on set. For the first couple of months I spoke only in a British accent and my family and my friends were freaked out by it when I'd call!".

'V for Vendetta' opens today