"I think marriage initially involves a lot of people who have nothing to do with your relationship, because it's a legally binding contract, and that has a weight to it," she says. "Being married is different than not being married, and anybody who tells you that it's the same is lying. It changes things. I have friends who were together for 10 years and then decided to get married, and I'll ask them on their wedding day or right after if it's different, and it always is. It is. It's a beautiful responsibility, but it's a responsibility."
She also has no problem discussing her belief that being monogamous isn't "natural."
"Well, with every gain there's a loss, right?" she explains. "So, that's a loss. You have to choose a path. I think the idea of marriage is very romantic; it's a beautiful idea, and the practice of it can be a very beautiful thing."
"I don't think it's natural to be a monogamous person," she continues. "I might be skewered for that, but I think it’s work. It’s a lot of work. And the fact that it is such work for so many people -- for everyone -- the fact of that proves that it is not a natural thing. It's something I have a lot of respect for and have participated in, but I think it definitely goes against some instinct to look beyond."
Still, Johansson has decided to take the plunge twice. She was previously married to Ryan Reynolds, though they split in 2010 after two years of marriage. The Ghost in the Shell actress married Dauriac four years later, and the pair has a daughter together, 2-year-old Rose.
Johansson says her second marriage definitely felt different than her first to Reynolds.
"I had a baby, and also my husband was coming from another country and becoming a citizen of this country," she shares. "It was a huge transition for both of us, and certainly for him -- moving here, committing to the States. But I think my husband has embraced America, and New York in particular, in this really endearing way. He was making meatballs the other night, actually. I wasn't home. I was away, and he sent me a picture. He was like, 'I'm a real New Yorker, and I love The Sopranos!' I was just, 'You go, babe.'"
"It felt different," she recalls, "I had a really young baby at the time, so that also -- our family dynamic was just different. I don't know. Whatever that is, the thing you can't fully put words to, it changed."
Above all, Johansson calls being a mother the "best thing that has ever happened" to her.
"Somebody once described it to me as your heart growing this other chamber, and I think that’s really profoundly true," she says. "Your capacity to love something, at least in my experience, deepens to a whole other space. I think I was afraid that life would change, and it does; it dramatically changes. But I feel in a lot of ways more myself now than I did before."
"I don't profess to know anything about parenting, anything more than anybody else, [but] being a working mom is an incredible challenge, [and] it's an incredible gift," she said. "I think you always feel a little bit of guilt… If you're at work, you feel like you're missing out on those special moments with your kid. If you're with your kid, you feel like you're not giving enough to your job. It's a balance."