When she's on her own and suitably relaxed, you can hypnotise Rosario Dawson. Eighteen months ago she visited a woman who laid her down, wrapped a blanket up to her neck and started talking. Dawson's thoughts wandered, her temperature dropped and she drifted in and out of sleep: the sweet spot of a trance-like state.
The hypnotherapist looked for tells, taking notes of every spasm and twitch. She talked and watched and picked apart what Dawson thought she wanted to explore from what was really on her mind.
"She was reading where I was, subconsciously, from my feet," says Dawson, who went through this bout of therapeutic dozing in preparation for her role in the new psychological thriller Trance . "I was reading in this book, What Every Body is Saying [a body-language manual written by ex-FBI agent Joe Navarro] that your feet are your most honest part of your body. Over everything else. You lie with your face. It's the worst indicator of honesty. And as you go down the body it becomes more and more honest."
Dawson talks in long, fluid bursts. She smiles a lot, maintains eye contact near constantly, but her feet are planted square, saying little. Trance, Danny Boyle's first film since the success of last year's Olympics opening ceremony, is similarly cryptic. Dawson plays Elizabeth Lamb, a hypnotherapist hired by a crime boss (Vincent Cassel) to recover the location of a priceless painting from the mind of an amnesiac fine art dealer (James McAvoy). It's a strange film – garish and energised, almost overpoweringly bright: a series of woozy thrills strung together with a line of logic that evaporates after the waking dream is over. It's part Inception, part Vanilla Sky.
It's also the rare film that gives Dawson – hitherto cast as a squeaky clean muse (Seven Pounds), a tsk-tsk maternal influence (Clerks II), or a frenzied sexpot (Alexander, Sin City, Death Proof) – the chance to skip between typecasting. The actor, who started a relationship with Boyle shortly after filming Trance (the couple have reportedly split since), is the film's linchpin. She plays Lamb as a femme fatale who uses her body and mind to manipulate and control. She's not vampishly sexy, nor comically evil. In a story full of violent men, going all in to reveal each other's hands, she is subtle and controlled, the best poker player of the lot.
"As smart as she is, and as understanding as she is about the subconscious and the mind, she's still dealing with very unpredictable characters and situations," says Dawson. "She's constantly thinking on her feet and having to change her strategy. I really liked that. I didn't want to get to the point of being arrogant with her confidence. That nothing ever changed for her and that she was always so perfectly composed – that sort of femme fatale would be boring."
Dawson, born in 1979, is of Native American, Irish, Puerto Rican and Afro-Cuban descent and was raised in Manhattan's Lower East Side. Back then, the neighbourhood's gentrification was still a decade away and she lived in a squat refurbished by her mum, a writer and singer, and her adoptive dad, then a construction worker. Her biological father had left after her mum became pregnant with Dawson when she was 17. This, it transpires, is the issue that prompted the trance-state foot-jerking.
"That was the question I had meeting the hypnotherapist," she says of her missing parent. "It was the one I wanted to avoid asking, but it was still kind of there. I wonder if part of [this film] has been the landscape for finally being ready to ask the question?"
Hypnotherapy planted the seed of an idea, but it was Dawson's dabbling in another class of mind game that let the suggestion take hold.
"I did a session with a psychic," she says. "She was really bold. She told me that my dad was dead and was speaking to me from beyond the grave. And I was like: 'I don't know if you're a good psychic, or if you're just pulling my leg – because I don't know this fact.' That was really wild.
"I'm so curious about stuff. I will research a character to the umpteenth degree. And yet there's this big gaping question mark in my own personal life that I have not looked at."
A few months ago, she hired an investigator, a $500-a-job guy who had helped a friend in a similar situation. He's already coming back with results.
"We think he died in 2001," she says. "If he passed, I'm sad about that, but in some ways I think I'm slightly relieved. It's Pandora's box you're opening. And I think it would have been weird to have to feel like I need to create a relationship later. As an adult if you were lwhat's the point of doing that unless you're wanting to create something?"
Dawson doesn't find it too painful to think about the death of a father she never knew, because she never felt as if something was missing. She had a dad: Greg Dawson, the man who married her mum when she was pregnant (the pair have since separated). Rosario describes Greg as "a hero" ("he chose me and wanted me"). And she's not worried that her search for her biological father will upset him.
"He met him," she says. "He knew him. Apparently he [her biological father] had come into my life when I was four – no one thought to take a photo. My mum always said it was two weeks. I talked to my dad and he was like: 'No, it was a good month. He came over and you guys spent a lot of time together. You were so excited about having two daddies.' "I was four, so I don't really remember any of that, but it was just nice that all these other stories came up . Curious things. This blurry figure starts to get crystallised."
It is because of Greg that Dawson got into acting at all. Her career was jumpstarted in the summer of 1994, when Vibe magazine was shooting a commercial on her block. Greg told her to go downstairs and get discovered. So the 15-year-old hung out on her stoop, shyly ogling her first crush: a grip ("His name was Michael Denzel, if I remember rightly") who was working on the shoot. "He wore the exact same outfit for three days straight," she says. "It was disgusting actually, I should not have had a crush on him. But he was the reason I didn't just get bored and f*ck off. I was hoping to get discovered by him to a certain extent."
So she sat, hoping Denzel was watching, when another man – homeless, long hair, bright blue eyes – approached and asked her if there was any room in the squat. They struck up a conversation, but Rosario was up on the step and this man was six feet down on the street. He was mumbling and laughing to himself and Dawson couldn't hear him but she was laughing when he laughed, trying to read his body language.
"I didn't know what he was talking about," she says. "I remember thinking: 'This guy looks like Jesus and I'm humouring Jesus.' I thought that was the funniest thing. So suddenly I just guffaw-laughed. Probably really obnoxiously. And this group of people turned and started staring at me."
Among them was photographer Larry Clark and the writer and future film director Harmony Korine. Clark, 52 at the time, had recruited 19-year-old Korine to write a teenage Aids story set in the New York skate scene. They were scouting for locations for the film that would become Kids, one of the most controversial films of the 1990s, thanks to its frank (some would say irresponsible) depiction of teenage sex. Clark and Korine immediately took a shine to the girl laughing on her front step. They introduced themselves and (after checking with Greg) Dawson agreed to read for them. She was given the part of Ruby, and spent four days playing the straight-talking running buddy to Chloë Sevigny's character, an HIV-positive teen who spends the film trying to find her ex and warn him about her diagnosis. Kids was a hit at the following year's Sundance film festival, catapulting Sevigny and Dawson into the limelight.
"It just seemed like this nothing thing," says Dawson. "Four days, one film and a high school theatre 101 class later, I have an agent and a movie out in theatres and I'm auditioning. And it's been my life ever since."
Since Kids you can roll the dice on the quality of a Rosario Dawson film. An appearance in Spike Lee's He Got Game (and a powerful turn in Lee's under-rated 25th Hour) suggested she might make the jump to arthouse icon, as Sevigny did. But those more challenging roles – along with intense turns in small, self-produced movies such as 2007's Descent (Dawson plays a college student who enacts brutal revenge on her rapist) – tend to get blindsided by second- or third-fiddle parts in bigger, blander fare. You may not remember her in Men in Black II or Pluto Nash, but she's there, bringing the energy, playing the game, clocking up the credits.
Part of the problem could be Dawson's looks: she's very beautiful. It's the first thing her Trance co-star, Vincent Cassel, talks about when I mention her. "Years ago there was a director who asked me: 'If we cast a female lead – and knowing that you have to have this love affair with her – who would you like to kiss?'" he says. "There were three actresses. And she was definitely one of them." (The second was his wife, Monica Bellucci. He won't reveal the third – he doesn't want to jinx it.)
He's being charming, but it's telling where his focus lies. Still, Dawson doesn't seem too perturbed. "I've tried to fight against it at certain times in my career," she says. "Looks are fleeting, you know? Your face can change, or something could happen to me. And I don't want to feel like that's all I have to give, because that would be very fragile".
Plus there are worse things to be than very good-looking in the acting business. And you imagine she has a backup plan. All that reading about hypnosis? All the work clocking body language and decodifying behaviour? Could she fall back on hypnotherapy if the parts dry up?
"It is kind of seductive to think about learning it," she says. "Even if it was for an occasional trick at a party". She whispers: "I know what you're thinking … you're getting sleepy …"
