Parental guidance suggested

First things first, though: There is an elephant in the room. Her son Matt Damon has starred in some of the more violent mainstream movies of the past few years - "The Departed" and "The Bourne Ultimatum," to name a couple.

In an interview in her Somerville row house, which is liberally decorated with artwork by her older son, Kyle Damon, a mixed-media artist, she speaks publicly for the first time about the violence in Matt's movies.

"Do I wish my son didn't make movies with so much violence? Yes," says Carlsson-Paige, who has earned national acclaim for her groundbreaking work on the impact of media violence on children. "In my perfect world, our artists would show us a way out of the violence we are immersed in instead of perpetuating it. But what I wish for even more is that society didn't crave violence so much, because it perpetuates a cycle of violence that only produces an appetite for more and more of it. What I focus on is that we have to find ways to protect children from exposure."

She would like for it to be illegal to market a film or its spinoff toys and products to children younger than the age for which the movie is rated. She is about to embark on a speaking tour to talk about that issue.

Damon says his mother's views are always in his mind. "I've always made my decision about what movies to make with an eye toward these issues," he says over the phone from London, where he was taking a break from shooting "The Green Room" in Morocco. "I've grown up knowing about all this, after all. As a high school kid, I'd come home to find my mom in the living room watching TV cartoons, counting acts of violence, and I would watch with her, to see what she was looking for. . . . I accept and agree with what she says - that it desensitizes kids, that there could be blowback from it."

His concern led him to refuse to allow his likeness to be licensed for any "Bourne" toys or video games. "I lobbied hard [with the video producers] to not make a first-person shooter game but to make it more like Myst, which was a great interesting puzzle you tried to solve - you know, to play with his amnesia or his memory," he says. "They weren't interested. They made the video anyway, without my likeness."

He adds, "I'd like to think that I at least made them more aware of the issues. That's step one. Step two is changing behavior. I learned that from my mom, too."

An 'a-ha' moment
It was 1984 when Carlsson-Paige realized how media violence was changing childhood. An early childhood educator at Lesley University, she was giving a math workshop for teachers. "All they wanted to talk about was what they called 'war play' - the way boys in their classroom were acting more aggressively, how their play was changing," she says.

A divorced mother raising two sons, her interest was piqued. (Her name, which she changed after her divorce from Kent Damon, is a combination of her mother's maiden name, Carlsson, and her own birth name, Paige.) She and colleague Diane Levin, now a professor at Wheelock College, surveyed teachers in 19 states. They determined the phenomenon was nationwide. It didn't take much for them to find the cause: The federal government had lifted limits to allow marketing to children on television.

The link they made between the change in play and the influence of what is commonly known as deregulation was a proverbial "a-ha" moment that reverberated throughout the early childhood field. It led to Carlsson-Paige and Levin's first of four book collaborations, "The War Play Dilemma."

Now a professor at Lesley, Carlsson-Paige looks at any change in the culture and wonders what it means for child development. It's a question that's been haunting her since Jan. 25, 1990, when Kyle's childhood best friend, Jesse McKie, was stabbed to death on a Cambridge street. Five teenage boys wanted his leather jacket.

"How did those young men who killed Jesse come to do that? How were they capable of doing that?" she asks.

The oft-offered socioeconomic reasons of inequality never satisfied her. It was in looking for something deeper that she arrived at the premise for "Taking Back Childhood," which is dedicated to McKie.

"Today's average child spends four to four and a half hours [a day] in front of a screen," she says. "That's time not spent interacting with other children or parents; time not spent at play, thinking about what you want to do and creating ways to do it; time not spent gaining the experience of taking another person's view point and working out conflicts peaceably. These are losses for children. They are dramatic changes in childhood. They concern me very much."

A political awakening
Carlsson-Paige, who dresses simply and has a warm, magnetic smile, wanders into the cubby area of the kindergarten classroom at the Fayerweather Street School, an independent school in Cambridge where she often comes to observe children. She stoops at a boy's level, her blue-gray eyes locked on his, as he tells her about what happened on the playground.

"So it sounds like you and your friend couldn't agree on what to do," she murmurs. "Tell me more."

In turn, other children gravitate toward Carlsson-Paige, too, even though she has never before met any of them. "I have good chemistry with kids," she says modestly.

Kyle Damon affirms that's especially true with his sons, Jackson, 10, and Miles, 8. "She's coming for dinner tonight," he reports on a recent weeknight. "They're very excited."

He and wife Lori live nearby in Cambridge, and Carlsson-Paige picks up the boys at school every Friday. (She has three other grandchildren: husband Doug Kline's daughter's infant son, Matt's 9-year-old stepdaughter, and his baby. Matt's wife, Luciana, is pregnant with their second child.)

Among her prized possessions is a drawing Jackson gave her on her recent 64th birthday. It shows military vehicles shooting scoops of ice cream. The caption reads, "Let's hope this is what happens to the military."

"He so has me pegged," she says with a laugh.

Her grandsons recently have been asking a lot of questions about a photo of Nanny that's in her home office. Taken in 1987, it shows her being dragged by officers into a police wagon. "I tell them, 'I was trying to stop a war in a place called El Salvador'," she says. " 'This was the way I was trying to do it, without being violent. I was trying to tell our government to stop sending money that was buying guns that was hurting people.' "

Carlsson-Paige credits historian Howard Zinn with her political awakening. For four years after her divorce, beginning when her sons were 5 and 2 and she was teaching kindergarten, Carlsson-Paige lived in Newton. The Zinns lived next door.

"Growing up [in a suburb of Albany]," she says, "there were never political discussions in my family. It was something I longed for. Living next to Howard was like a full-time tutorial."

Zinn and Carlsson-Paige remain close even now, years after she moved to Cambridge in search of a more progressive education for her sons. Says Zinn, "Nancy has been building toward this book her whole career."

Her goal in writing the book, she says, is to give parents a big-picture look at how the culture is affecting childhood and to provide coping skills for the day-to-day struggles that arise from cultural issues, such as children's exposure to too many ads, or repeatedly seeing messages that say might makes right.

"There are so many negative messages in the culture these days, it's hard for parents to even recognize them any more," Carlsson-Paige says.

Ever a realist, she acknowledges that some people will buy her book only because it's written by Matt Damon's mother. (Groupies' alert: The book contains about seven anecdotes from Matt's childhood.) She's not offended. "I just hope they read it once they buy it," she says.