SARA Stewart’s performances over the years in West End theatre and on television, in Sugar Rush, Miss Selfridge and Fresh Meat reveal a performer who understands implicitly that nuance plus truth add up to believability.

That truth has been a little easier to find however in rehearsals for her latest theatre role. Stewart plays Martha in a new production of Who’s Afraid of Virginia Wolf?, Edward Albee’s searing dissection of the breakdown of a marriage – with all its intendent bickering, savagery and character assassination.

The actress reveals why it has been top of the roles she has always wanted to play. “I read it 25 years ago and fell in love with it,” she maintains, during rehearsals for the Michael Emans production. “Albee, you see, has written about people who were like my family. My grandfather was a New York publisher. My mother was an academic and went to Harvard, but had a nervous breakdown. She was not mentally stable and became an alcoholic who drank herself to death.

“My parents were deeply unhappy and I grew up in that world of two repressed Fifties American academics who were continually outsmarting each other. It was a world of verbal warfare.” She adds, in soft voice; “I think there was a lot of repressed emotion in the family.”

Stewart, who grew up in Edinburgh but has something of a hybrid accent (she spent her summer holidays at her grandmother’s home in Connecticut and has lived in New York), understands the frustrations of woman who has so much, yet can feel she has so little.

“My mother had a genius IQ, she was incredibly beautiful, but she lived with this sense of disappointed expectations. She should have been a writer, but wasn’t. And her husband wasn’t quite as clever as her. I guess she felt it was isolating being so clever because there were so few people she could relate to.”

Stewart, who played Martha Wayne in movie Batman Begins, adds; “I think if you are a very intelligent person with high expectations you end up dumbing down to try and connect with someone on another wavelength. My mother had high opinions of herself, but was so under-confident at the same time. At one point she was on a high trajectory, she worked for Newsweek, but she kept slipping, somehow paralysed by mental illness.”

There are real parallels with Martha, played by Elizabeth Taylor alongside Richard Burton in the 1966 film. “Martha was part of this generation of brilliant women who were frustrated because society didn’t give them an outlet, stuck behind their husbands. And if they are cleverer than them, how frustrating was that?”

Stewart’s New Yorker parents went completely against the grain of that time in immigrating to Scotland. (The story made the papers.) Her father was an English teacher and her mum a social worker who met during a summer course in Edinburgh.

“We were quite exotic,” she says, smiling of growing up in Edinburgh. “I remember we had salad and radiators.”

Her parents’ were connected to the arts world. “We were surrounded by theatre. If anyone came to Edinburgh during the Festival we’d be involved somehow. I’d work backstage and my mum would cart me off to the Theatre Workshop whenever she got the chance.”

She adds, with a knowing grin: “I was a lively spark and she wouldn’t have the energy to cope with me so I’d be farmed out to theatricals a lot, to youth theatre and later on I got into the National Youth Theatre.

“Acting all seemed so natural and when I was seventeen I went back to America and was cast at Brown University summer season, landing all the lead roles."

The Stewart was accepted by Central School of Drama in London. “It was my Sliding Doors moment. I could have stayed in America.”

The actress admits she enjoyed a freedom her mother never had. “I could grow up and work and have a family. Yet, I felt I had to have a boyfriend, to find someone to have babies with, which I did. Now I look at my daughter’s life and it’s very different. She doesn’t define herself by being attractive to men.”

Many actors would avoid a role such as Martha which resonated so clearly with their own life. Martha and George’s unravelling relationship, she reveals, also bore similarities to her own break-up.

“Yes, I know things can get really down and dirty. So Martha and George didn’t shock me.”

But isn’t she uncomfortable re-living some of that war on stage? “No, I love it,” she says, grinning. “I love working those muscles. I don’t have anyone to argue with any more.”

Her voice takes on a little more serious tone, yet arrives attached to a wry smile. “Listen, I’m not like Martha. I’m not an extreme creature. But what I also love about this play is it’s really funny. The humour is dark, witty and savage. And as an actress, it’s my job to bring out the laughs.”

*Who’s Afraid of Virginia Woof? also features Rose Reynolds, Robin Kingsland and Paul Albertson, and tours Scotland from May 4, opening at Stirling's Macrobert Art Centre and including the Theatre Royal, Glasgow May 30 – June 3.