Sarah Ruhl’s new play, The Oldest Boy, is dedicated to her three children – 8-year-old Anna, and 4-year-old twins, William and Hope -- and to their Tibetan nanny, Yangzom. The other day, in the large LCT rehearsal room, Ruhl said that the play has its origins in a story told to her by Yangzom.

“The play is based on a true story,” Ruhl said. “A couple in Boston, who ran a restaurant, were visited by monks who recognized their child as a tulku” – a high-ranking lama who can choose his own rebirth. “The child would be taken to a monastery in India. The parents closed the restaurant and went to India – for them, it was a great honor to have their child recognized.”

In Ruhl’s play, a young couple face a similar situation, but their attitude is somewhat different. “In my imagination, I wondered what it would be like if you were an American mother, with a Tibetan husband, in a similar situation.” Ruhl said that the theme of intercultural marriage has interested her ever since she met her husband, Tony Charuvastra, who is the child of a Thai father and an Australian mother.

The gestation period for The Oldest Boy was approximately two years. “I tend to turn an idea over in my head for at least a year,” Ruhl said, “before I begin writing. I need to see if an idea has staying power before I sit down to write.” She added: “Structurally, the bones of a play tend to be in place with the first draft. Then I rewrite. I don’t know what a play is until I hear it with actors.”

Ruhl said she was raised Catholic and was keen to do as much research as she could possibly do about Tibetan Buddhism and the Tibetan community in exile. She started with reading anything she could get her hands on, including all the works of the Dalai Lama. "I read anything and everything by the Dalai Lama, as well as his mother and brother's autobiographies." (In a fine bit of synchronicity, the Dalai Lama will be appearing near Lincoln Center, at the Beacon Theater, on November 3rd, which is the opening night for The Oldest Boy.) As well as reading widely (hundreds of books are arranged in piles on a table in the rehearsal room, a cache I plan to plunder for an upcoming blog posting), Ruhl and the cast did interviews with Tibetans, including Tibetan lamas.

Ruhl said that The Oldest Boy contains parallels to The Clean House, her previous play in LCT’s Mitzi Newhouse space. “In the first act, you think you are in a living room. A visitor arrives. In the second act, you are clearly not in a living room.”

Other aspects of the new drama represent a departure. “I’ve never put a child onstage before,” Ruhl pointed out. "I think we're in an interesting moment culturally, where artists who are also parents are writing and thinking about parenthood in new ways, putting children in their art." She added: “Dickens had 9 children, but he didn't change their diapers. He couldn't have written My Struggle.”

Children have interested Ruhl recently not just as a playwright. She has just published a non-fiction book, in which they are among the subjects of scrutiny. The volume is called “100 Essays I Don’t Have Time To Write: On Umbrellas and Sword Fights, Parades and Dogs, Fire Alarms, Children, and Theater.” And Ruhl’s play-in-process, about her actress mother and Peter Pan, also promises to examine the subject of children and their growing up.

Brendan Lemon is the American theater critic for the Financial Times and the editor of lemonwade.com