She's starring in a film about a destructive marriage headed for catastrophe so it should come as no surprise to learn that Rosamund Pike has strong views of her own on relationships.

The 35-year-old Gone Girl  actress, who is expecting her second child with partner Robie Uniacke, says we are too dependent on our other halves nowadays.

 "People have ridiculous expectations of a mate," the film star told Spectrum magazine. 

"In my grandmother's day, you wouldn't expect your husband to fulfil the same need in you as your sister, or girlfriends, or colleagues at work. You'd have different needs met by different people.

"Now we want all our needs met by one person, and I don't believe that's possible. Or rather, it is, but I don't think it's universally achievable."

The actress, who lives with her 53-year-old partner Uniacke and her daughter Solo in north London, said she likes to maintain an element of distance in her relationship so that one person is not reliant on the other.

"I do think separation is key to a relationship," she said. "I go out with my partner and we are put next to each other – there's a feeling of, 'What, you don't think we can't operate without each other?' I don't need him as a crutch. Of course, he's the person I want to go home with but he's not necessarily the person I want to sit next to. I'd rather meet someone new, and he would too."

Pike previously dated Atonement director Joe Wright and he proposed to her in 2008 on Lake Como. They had sent out save the dates to their wedding guests when Wright abruptly called things off. The Oxford University graduate also dated actor Simon Woods, who later turned out to be gay. 

The actress plays the emotionally disturbed and manipulative Amy Dunne in Gone Girl. She credits her current partner Uniacke, a mathematical researcher and former addict, with helping her to shape her film characters. 

"I have a very clever partner who’s got a very astute mind and is very, very well read and articulate and ruthless about how something I do might play out on screen," she told the Telegraph earlier this year. "My tendency is to identify with a character and imagine there is more on the page than there is. He’s quite good at putting a check on that."

"I feel very uncomfortable because people think I have walked into this profession through connections and looks," she added. "And they somehow think it’s easy – and it’s not f****** easy. I don’t have connections. And I didn’t have parents, or a social set, who had anything to do with the film industry."

Gone Girl has stormed the box office charts this weekend, taking $38 million (£23.7 million) in its first two days of release. 

Based on the best-selling novel by US author Gillian Flynn and directed by David Fincher, the film tells the story of a man who comes under suspicion after his wife mysteriously disappears. 

Pike and Ben Affleck star as two people caught up in an increasingly fraught and destructive marriage.

Pike, who made her debut in Bond film Die Another Day, had not read the book before she was cast but says Fincher's instincts were spot on in approaching her for the role of Amy:

"It’s disturbing. I said to him on the phone, 'You’ve got this uncanny impression that you know I’ve got this part in me and I feel I have. I don’t know how the hell you know that.'"

Pike told Indiewire she struggled with the weight fluctuation that the part required.

"I had Christmas break, two weeks to gain it again," she said. "And then I had time to lose it again. It’s like turning your body into a chemistry lab. It’s wasn’t like 30 pounds that we’ve seen people do in the past. It’s like you’re on a sugar high or you’re hungry. It's another emotional stress of the job, I think. It’s not entirely healthy." 

Gone Girl is out in UK cinemas now