The thoughtful teen star of ‘20th Century Women’ shows a knack for surprising adults

Lucas Jade Zumann can be a focused, idealistic teenager. So when director Mike Mills called — after months of waiting and not much hope — to tell the 14-year-old he’d booked the male lead in Mills’ new movie “20th Century Women,” Zumann didn’t break stride.

“He was building a greenhouse outside when he took the call,” Zumann’s mother, Jennifer, recalled of the moment at the family’s Chicago-area home. “He opened the window to say he got the part. My husband and I screamed. Lucas didn’t scream. He said. ‘Can we go to Home Depot? I need a board.’”

The young man has a simple explanation for his muted reaction. “I was in the zone.”

In this fall film season characterized by reliable talents at the top of their game — “Women” itself is generating Oscar talk for star Annette Bening — Zumann offers the other side of the equation: the joy of discovery.

The teenager, who previously had a small part in “Sinister 2,” has the kind of composure both on- and off-screen likely to make you feel heartened about the future of screen acting — and wondering if some young people just bypass the kid stage.

Set in Santa Barbara circa 1979, “Women” features Bening as a 55-year-old single mother, Dorothea Fields, attempting to raise a teenage boy despite a significant generational remove. Mores and music are changing rapidly, and Dorothea tries to square what she believes about child-raising with a world she fears may be passing her by.

Zumann plays her son, Jamie, in the film, which comes out in December after its New York Film Festival premiere earlier this month. If Bening must radiate confusion about forces outside her control, Zumann must hold up a different end of the bargain: figuring out who you are in a time of great tumult.

The young actor steers the character between two cliched poles: the sullen, inaccessible teen and the precocious indie-film child smarter than his parents. Watching him, one is tempted to recount the director Tom McCarthy’s credo for how to portray adolescence accurately: “Teenagers know everything that’s going on. They just don’t let you know they know what’s going on.”

Making it trickier is the fact that the film is based on Mills’ own relationship with his mother. For Zumann, that meant he was portraying the director as a young man — his character model, basically, was also his boss.

“When we were filming I would always ask Mike the story behind a specific scene, and he always gave me a detailed story,” Zumann, now 15, said. “I was trying to make it seem like I was just bantering with him but in my head I was taking notes a million miles a second trying to study him.”

Taking stealth mental notes is the least of Zumann’s adult qualities.

The teenager, who is being home-schooled, is the oldest of four brothers. As far back as anyone can remember, he was always the kind of kid who would transcend his age.

His father, Matt, said when Lucas was barely in grade school he would act as the unofficial greeter for the family Pilates business, welcoming strangers and clients at the door.

Zumann also had a preternatural interest in filmmaking, and began asking for camera equipment for holidays and birthdays from a young age. He began shooting invented stories wherever he happened to be; one family vacation he decided to make a ghost story.

“It was like he walked into where we were staying and thought ‘this house needs a movie,” Matt Zumann recalled. That movie has been accidentally deleted, Matt and Jennifer noted ruefully, though they perked up when hearing about all the director greats who had made early films now lost to history.

(The Zumann family is waiting for “Women” to roll out before booking Lucas’ next gigs. Demonstrating he already has a knack for Hollywood diplomacy, the younger Zumann said of his veteran acting counterpart, “I think as both surrogate mother and co-actor-actress Annette and I were really great. We had a much better relationship than Jamie and Dorothea.” Bening, incidentally, also gave advice to the family, telling Jennifer and Matt that time off between gigs was important so both career and childhood didn’t become a kind of psychological treadmill.)

On the set of “Women,” Zumann rarely went back to his trailer, sidling up instead to various members of the crew and asking them what they did and how a given machine worked. “It was like a free film school,” he said.

He added that he’d like to work behind the camera. Or, more accurately, he added that he’d already been working behind the camera.

“I’m currently writing some stuff and have a film company with my friends. We did a short film about sustainable transportation. Sustainability is very important to me,” he said.

Zumann speaks with a quiet manner and extreme poise; talking to him, adults might wonder if they’d accidentally stepped into the world of “Big.” Mills, who combed through hundreds of kids to find the right fresh-faced actor, said he remained confounded by Zumann.

“I don’t get him. Like, I literally don’t know where someone like that comes from,” Mills said.

The director described an on-set fascination with Rastafarian culture, but apparently that’s over now. “It was a phase,” Zumann said sheepishly, then moved on to talking about environmental concerns.

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