Paul Dano and Zoe Kazan, a real-life couple, joined with another couple, Jonathan Dayton and Valerie Faris, who directed Dano in “Little Miss Sunshine,” to film Kazan’s screenplay “Ruby Sparks,” about a nervous novelist with a serious case of writer’s block who literally conjures up the girl of his dreams by describing her on his old manual typewriter. Ruby, as he calls her, is entirely amenable to his wishes—until she starts showing signs of independence and he has to decide whether to keep her under control or set her free. All four came to Dallas recently on a tour for the film.

“I have to say, I think that we are getting less credit for this [on-screen] chemistry thing than we should be,” Kazan, the granddaughter of legendary director Elia and daughter of screenwriter Nicholas, said in reply to a question linking their performances to their off-screen status. “I watch movies where people are together, and so often I feel that there’s less chemistry. We worked very hard—we didn’t kiss for, like, the first two weeks of filming—to try to bring up that feeling of newness because we’d been together for so long, and that sort of butterfly stage is long gone. I’m just kidding, really,” she added, glancing at Dano, who sat beside her. “I’m glad there’s chemistry. I was nervous.”

Dano added, “Me, too. I mean, it was not without its challenges, but work was really fun. Going home after a fourteen-hour day and being stuck in traffic, and all the little domestic issues would occur, but I think it was pretty good.”

“We challenged each other on a regular basis,” Kazan said.

“I think that’s probably one of the best things we do for each other,” Dano agreed. “We challenge each other, and hopefully inspire each other in some ways, and also respect each other’s work. So if we are working together, we allow each other to do what we do, and if we’re not working together, we help give the other person what they need.”

“We talked very early about us being in it,” Kazan explained, “maybe [when] I was five pages into writing. We both felt, even more than wanting to be in the movie, we wanted to retain control over it, because I could have sold the script and I think it could have been made into a very different kind of movie. So we only brought it to a handful of producers—they were all independent producers—and we brought it to them with the condition that we were going to act in it, and with the condition that it couldn’t be rewritten—[that] this is the kind of movie you want to make, or it’s not. We knew what kind of movie we wanted to make.”

“We also knew our first choice of director was Jon and Val, really early in Zoe’s writing, probably ten pages in,” Dano added. “That idea came up, and it was always the polestar, our dream choice. We knew that we wanted to aim high, and it was sort of a take-it-or-leave-it thing. So we took it to a bunch of producers, and those that were interested in working with Zoe and me and liked the script met with us, and we went from there. Luckily it wasn’t that hard. I think had Jonathan and Valerie not signed on for the film, then it would have been a totally different thing. We got very lucky.”

Kazan added that Dano, who also served as an executive producer on the picture, “has a great mind for producing. He’s got a great business head—I expected that, but I didn’t know. It was neat to see that side of Paul.”

“I’ve done a couple of small films [as executive producer],” Dano explained. “It’s sometimes silly when actors take that title and often it’s meaningless, or it has to do with getting one extra point on the back end of an independent film where you don’t get any money up front. It can be a totally insignificant thing. I think the reason I’ve done it on a couple of films is just having been involved very early in the process, hopefully helping to be a creative facilitator, helping put it in the right hands if I have access to people. In this case, just doing my job since Zoe was the writer, just helping to facilitate it. Not being on the phone to financiers. That’s part of making a good film—if you put it in the right hands, once you get there you don’t have to worry too much.”

In this case, four of the right hands were those of Dayton and Faris, who made “Sparks” their follow-up to their smash feature debut with “Sunshine” (2006). “Paul and Zoe brought in two of the producers on ‘Little Miss Sunshine,’ Ron [Yerxa] and Albert [Berger], and together they came to us with the first draft of the script,” Dayton recalled. “And we loved it right away and signed on, and immediately began working with Zoe on a new draft. We loved all the themes it explored and were excited to dig in and think about what the film would be, where thus would go.

“We knew that she was going to have to act in it, so we didn’t want her to have to split her duties when it came time to actually make the film. So it was very important to us to get the script exactly right.” But he emphasized that the script was still Kazan’s: “We worked on streamlining—there were substories that we took out. We made the last thirty minutes a little different. But the great thing about Zoe is that she’s an incredible re-writer. She wrote everything.” Faris added, “We’d throw out an idea, and she wasn’t possessive or precious with the material. She’d go, ‘Hey, let me go try that.’ And she’d come back with something that was usually better than what we had imagined. That’s very rare for a writer.”

On “Sunshine,” the duo had actually acted the script out in their garage, and, Dayton said, “we did exactly the same on this.” Faris added, “We just take advantage of the fact that there are two of us and it allows us to explore scenes together privately and have a sense of what we’re going to be asking of our actors. The more you know going in, the better, and so we try to put ourselves through the paces as much as we can, so that on the set we really know what we’re chasing after.”

“We’re not writers,” Dayton emphasized. “We’re always involved heavily in that, but there’s a point where we have to take the reins. Zoe’s been with this for a year, and we need to have the same deep connection.”

Dayton emphasized that a dark turn the script took toward the close—in a scene that he and Faris discussed but too much information here would spoil—was especially attractive, and challenging, for them. “That was one of the things that excited us about it,” he said. “A lot of time people don’t want to go to a hard place. Studios don’t want you to go to a hard place. They want to keep it all light and fluffy. But we liked was that this was a roller-coaster ride. You start laughing and go through all these different places.”

“Like you do in relationships, you know,” Faris interjected. “It’s not always just fun. They’re challenging and they teach you about yourself. So we wanted this to feel more—though there is an element of magic in this movie—like it came from real life.”

As for working together as a team on a project about a relationship, Dayton observed, “We both do everything, but I certainly think that we have both male and female experience represented [is important].” Faris added, “I think if anything, we relate to the material but from slightly different points of view. So we bring both perspectives to the work. But in terms of dealing with the cast, we really mix it up. We’ve done it together for so long that we really work hand-in-hand at all times. I don’t think of myself as a female filmmaker. I think of myself as filmmaker and I’m part of a partnership. Obviously I bring my experience and my gender as part of that, but that’s my focus.”

As Dayton put it, “There’s male and there’s female and there’s ‘all of the above.’ And I think we’re ‘all of the above.’”

And he summed up their enthusiasm for the project by saying, “With this strange fictional premise, you actually get to a lot of human truth, both for men and women.”

Dayton also pointed out that there are really two thematic threads at work in the film. “One is about relationships,” he said. “But it’s also about the creative process, and trying to create something that has life. I can only liken it to making a film. As a director you try to control every moment, every bit, and you can get a lifeless, mechanical piece. Our job is to encourage and stoke the flames that are stirring all over the set, to make it come together.”

Faris added, “And you have to really watch what’s happening. In the same way that [Dano’s character] Calvin creates Ruby, but once he tries to control her, it falls apart. We were interested it that idea—sometimes with creative work, you want to get everything exactly the way you wanted it. But there’s an element of give-and-take, in a relationship as well as in the creative process.”