It's what's inside Gordon-Levitt's 'Don Jon' that counts

• Joseph Gordon-Levitt wrote and directed %27Don Jon%2C%27 in which he plays a porn addict who meets his dream girl
• %22Scarlett and I got such a kick out of playing these characters%2C%22 Gordon-Levitt says
• If acting didn%27t work out%2C one star would be a therapist%2C the other a journalist

NEW YORK — In the parlance of Joseph Gordon-Levitt's new movie, Don Jon, Scarlett Johansson is a dime.

That is, an irrefutably perfect 10. She's his Layla, his Sweet Caroline, his Dreamlover — the kind of wondrously, astoundingly, gloriously flawless female whom a player like Jon (played by Gordon-Levitt) would want to bed every weekend.

"Scarlett does get reduced to that oftentimes in our culture. As I've gotten to know her, she's a super-smart person, a really talented artist, and yet a lot of what gets talked about is her looks. That's a big part of what Don Jon is poking fun at," says Gordon-Levitt, who wrote and directed the film and plays the titular puffed-up boor, whose life revolves around porn, church, family, car and friends. "Scarlett and I got such a kick out of playing these characters."

Johansson's Barbara is pugnacious, outspoken, self-assured and repulsed by Jon's X-rated habits. Early on, after they meet in a club and he pursues her on Facebook and asks her out, she warns Jon to never lie to her.

"She's got a lot of conviction, and I think I definitely understood, probably from my own personal experience, the conviction that she has is because she really feels right. She believes herself. She doesn't doubt herself at all," Johansson says. "I doubt myself often. But I do understand that personality at times. It's probably why she's successful in so many other parts in her life. It's why she's a catch. Unfortunately, it fails her here. You can't have an intimate relationship with somebody if you always feel right. I know that head-space. But I'm right right now!"

Gordon-Levitt and Johansson didn't know each other, except in passing as part of Hollywood's awards circuit, when he cast her in his film, which opens Friday. It took years to finish, because he wrote it in his spare time and showed it only to a few close friends, including director Rian Johnson. Speaking of, the back-and-forth Jon has with his friends, even heightened for the screen, is brutal in its scathing analysis of women's physical attributes. Johansson, however, wasn't bothered.

"I have those conversations. I often witness them. A lot of times, I'm the only girl in a group of men. I participate. You know how guys are. I see the way my brothers are. There's that masculine posturing — it's goofy and whatever — but there's a competitiveness," she says.

Yet for Jon, those connections with his buddies are the most authentic in his life. "Those are really intimate relationships, your friends. You can be safe, and they're not judging you," Gordon-Levitt says.

The message of the film, if there is one, is about the intense pressure society puts on people to behave a certain way — in the case of Jon, to build his entire sense of self-worth on his capacity to "pull" hot women.

"I've always been aware of that growing up in movies and in TV, and growing up with a mom who was always pointing that out to my brother and me. That's the message that's being sent here," Gordon-Levitt says. "I would credit my parents a lot with prioritizing what I think is important: caring about what you do, working hard, thinking about how what you do affects others. Not just getting what you can for yourself. They brought my brother and me up with those ideals."

He's trying to carry them through in his professional life. Gordon-Levitt has starred in Christopher Nolan's Inception and The Dark Knight Rises; he also runs his own "open-collaborative" production company, HITRECORD. And he earned glowing notices for playing a cancer patient in 2011's 50/50. As for Johansson, she just wrapped her turn as the Black Widow in Captain America: The Winter Soldier and is shooting Jon Favreau's Chef. So if the whole acting thing petered out for them, what would they do?

"It's funny. No one asks you that. No movies at all? Maybe I would have liked to be a social worker or therapist," Johansson says. "I have a terrible staring problem. I observe everything. I'm doing it right now. I always observe."

Says Gordon-Levitt: "You're really perceptive and empathetic to the way people are. My dad was a journalist, so that would interest me. This is a conversation my dad and I have all the time. It's ultimately about telling a story."

Johansson is guarded in interviews, opting not to discuss the engagement ring she's sporting from fiancé Romain Dauriac. She and her first husband, actor Ryan Reynolds, split in 2010, and she's never discussed either their marriage or divorce, except in very general, oblique terms.

"I'm a relatively private person," she says. "There are things that have happened in my life that have not necessarily been parts of my life that I'd like to live out publicly, not by choice have they been focused on or pulled apart. It's a hard balance. You don't want to be so closely guarded that (it) affects your life as well. I don't want to feel like I'm hiding myself. I understand that now more than I did before."

That attitude came from being a child actor who, at 19, became the muse of a generation with 2003's dreamy, whimsical Lost in Translation.

"Suddenly being thrust into the media spotlight, I became more of an object, and my love life became interesting to people. It's a strange adjustment to make," she says. "You become very protective. You feel like, what the hell is going on? People are following you and photographing you. You hide inside yourself. The more comfortable you are with yourself, the more you learn to balance those things. It's a strange reality."

She looks over to her co-star. "Joe's just boring."

Gordon-Levitt nods, laughing. "That's what I always say, and that's actually true."

Says Johansson: "I work constantly, and so do you. It's a big part of our lives. I need to get a habit or a hobby. I need to get arrested."