Jennifer Garner On The Emotional Toll Of Playing A Mother With Mental Illness

It's sometimes easy to forget how great of an actress Jennifer Garner is — media portrayals tend to highlight her as the potential friend who would be fun to get brunch with, rather than the next Meryl Streep. This is interesting, given her four Emmy nominations for the wonderful Alias, and memorable roles in critical darlings like Juno and Dallas Buyer's Club. But Garner's performance in The Tribes of Palos Verdes, which hits theaters December 1, demands to be noticed and talked about seriously. It's one of the darkest roles you've ever seen her take on; and thanks to her fearless delivery, it really, really works.

Based on the 1997 coming-of-age novel by Joy Nicholson, Tribes focuses on teenage Medina (Maika Monroe), who finds solace in surfing as her family unit implodes around her. Garner plays Sandy, Medina and her twin brother Jim's (Cody Fern) mom, whose struggles with mental illness only intensify after her surgeon husband moves the family to the prim and proper community of Palos Verdes, California. While her kids are out on the ocean, Sandy prowls around the house in her pink robe, cursing the constant barrage of waves crashing into the land below her house. Consumed by her own perceived slights and aggressions, she's blind to her son's descent into dangerous drug-use, instead constantly turning to him for the attention she doesn't receive from her husband.

To prepare for such an emotionally demanding role, Garner had to set some boundaries for herself on set and refrain from the social aspects of the job that she usually enjoys. "On this set, I spoke less to people than I think I ever have in my whole career," she tells Refinery29. "It was all, 'head down, I have to get through it.' And certainly we were all in it together, so it wasn’t like it was a me, or an us, vs. them. But it wasn’t like, ‘Hi, I baked something this morning!’"

Emmett and Brendan Malloy, brothers and co-directors on the film, say they made it a point to give Garner space to navigate the heavier scenes that her character takes on. "Her dressing room was almost like her locker room," Brendan says. "She was in there, almost like a caged animal, pacing, knowing that she was going to go out. We pushed everybody to know that when she comes out, it’s on. We’re rolling the cameras. We’re not going to mess this up."

Though we, as viewers, never find out what form of mental illness Sandy is living with, Garner says she and her directors had several conversations with therapists in order to establish some consistent behaviors. Sandy's paranoia and co-dependence on her son makes her relationship with her daughter extremely volatile, a mix of resentment, jealousy and empathy, that Garner says she was excited to play out on screen.

"I have a mom and I have daughters, and I know how underneath it all, it's just such a full relationship," she said. "That's why I love playing moms in films. There's no relationship that can raise the stakes more quickly than that with your children. And while I hope that my kids and I never end up in any place near this, I do know that I love them enough that if things went awry, I know that it would be more explosive than anything else in my life."

You can see that back and forth in this exclusive clip from the film, which shows Sandy enviously taking in her daughter's looks and desirability while manically cutting herself out of a pair of Spanx.

Sandy's insecurities about her own value as she starts to age are heightened in the Palos Verdes community where women spend their days wearing tennis dresses and eating salads with dressing on the side. As a woman who regularly deals with the pressures put on women's bodies in Hollywood, Garner says she can relate — to a certain extent.

"I've never been a cool girl," she says. "I really like all the cool girls, and I always have. If I'm with them, I won't be uncomfortable, but that's just because they're nice. Women that I know in this town are nice. But I won't not just plop myself into the center of them because that's not how I live in the world. I would be nervous, or embarrassed, or awkward, or shy. And so, I do understand — but you can't even compare the way Sandy looks at the world. She's looking for the hypocrisy, she's looking for the underbelly of the town that she's found herself in. And that's not the way I would look at the world at all."

Like many great things, Garner's performance isn't always easy to watch, but it will stick with you long after the credits roll.

The Tribes of Palos Verdes opens in theaters and will be available on demand on December 1.