One of the strangest things about crying is that it goes in and out of fashion. "One must have a heart of stone to read the death of Little Nell without laughing," was Oscar Wilde's reported response to the demise of the angelic young heroine of Charles Dickens's The Old Curiosity Shop. Yet in Dickens's day - half a century before Wilde's, give or take - swishy sentimentality was in.
The Wildean worldview rules at the cinema, and has done for a while. Films that go out of their way to make us cry have often been treated with as much suspicion as films that go out of their way to make us jump. One of Pixar's lesser sung achievements is the way the studio made it socially acceptable, in the mid-Nineties, for adults to cry during animated films - though we surely feel more comfortable doing so because animation snaps us back to early childhood, when public displays of emotion are hourly occurrences. (I only cried once during Inside Out, though it was for about an hour-and-a-half.) But the weepie - the live-action drama where a visceral, emotional reaction is the whole point - remains a trashy genre.
You have Nicholas Sparks adaptations, young adult book-to-screen smashes like The Fault in Our Stars, and that's about it. Hollywood makes it, but sees it as kids' stuff. And that is where Derek Cianfrance comes in.
The director of Blue Valentine, The Place Beyond the Pines and the forthcoming adaptation of The Light Between Oceans is the master of the modern weepie. If you go into a Cianfrance film and emerge with dry cheeks, you might as well be wheeled straight to the nearest mortician. But formulaic and schlocky he is not: Blue Valentine was a word-of-mouth hit at Cannes and Sundance in 2010 and secured Michelle Williams an Oscar nomination, while The Light Between Oceans had its world premiere in competition at Venice in September. His latest is an adaptation of the M L Stedman novel in which a lighthouse keeper and his wife, played in the film by Michael Fassbender and Alicia Vikander, find a baby washed ashore in a lifeboat and secretly adopt it as their own.
Moving doesn't begin to cover it. There was so much crying in the screening, the ushers came in with sou'westers and mops.
I meet Cianfrance, 42, over coffee in Claridge's in London. The director, who looks a lot like his Blue Valentine star Ryan Gosling, was first handed Stedman's book by Steven Spielberg, that king of the weepie, at a meeting to brainstorm ideas for his next film. Spielberg told him that Blue Valentine, a wrenching divorce drama, had been his favourite film of 2010. Cianfrance suspected The Light Between Oceans might be for him when he found himself crying on public transport while reading it. "Which sucked," he says. "Emotion is embarrassing. It's the worst."
Occasionally, a weepie comes along that's big enough to buck the stigma of uncoolness - or at least make being uncool cool for a bit. Millions went to see Titanic over and over because they had a chance to cry en masse. A study in the June 2009 edition of the Annals of the New York Academy of Sciences found that watching sad things happen to fictional strangers caused a 47 per cent spike in the pleasure hormone oxytocin - which, in turn, increased the watchers' generosity towards strangers in real life. The study also revealed that the spikes in oxytocin caused by weepies varied between men and women - and yet again, neuroscience finds itself following where Nora Ephron led. In Sleepless in Seattle, Suzy (Rita Wilson) starts to cry while simply describing the plot of An Affair to Remember, while Sam (Tom Hanks) does the same later on, except he's talking about The Dirty Dozen.
Cianfrance's previous film, The Place Beyond the Pines, was the second type: a macho weepie, about fathers and sons and toxic emotional legacies passed down the male line. The director remembers thinking on set that his next film would have to be about mothers and daughters, just as some kind of antidote.
That said, he was excited to work with Fassbender, whose screen persona usually exudes power and control. Cianfrance insisted that his cast live together for five weeks on the actual island that appears in the film, and spent the first few days of the shoot filming Fassbender doing odd jobs. On day three, after two hours of hammering hinges in a woodshed, Cianfrance asked Fassbender to kneel down and pray - and as he did, a big, fat, unplanned tear rolled down his cheek.
"Secretly I'm behind the camera thinking, 'Yes! Michael Fassbender cried in my movie!'?" says Cianfrance.
Though the best weepies are not exactly formulaic, there's an underlying pattern worth acknowledging - which brings us back to Nicholas Sparks, the genre's multi-millionaire DNA sequencer. Sparks's books and the films adapted from them - The Notebook, The Lucky One, Dear John - are formulaic, and deliberately so: a couple (attractive, white) are held apart by some insurmountable force (war, class, family estrangement), then get their act together when someone close to one of them dies.
Also non-negotiable: the poster must depict the main couple almost, but not quite, kissing at magic hour - which might be why The Light Between Oceans was pegged as Nicholas Sparks for people who don't watch Nicholas Sparks films when its own identical poster was released. That's not entirely fair, though the film itself does adhere to the other big Sparksian tenet: it takes place near a large body of water.
Cianfrance chuckles when I raise this. It turns out he'd originally set Blue Valentine by the ocean, too. For him, water in weepies is a symbol of "significance and insignificance - a way of juxtaposing these tiny human dreams with the vastness of time."
Time makes a difference. The films now held up as the best weepies ever - from the women's pictures of the Thirties and Forties, like Stella Dallas and Brief Encounter, through to the swirling midcentury melodramas of Douglas Sirk - were first thought of as a kind of side hustle for cinema, rather than its proper purpose.
"Sometimes movies come out too early or too late," is how Cianfrance puts it - though there's undeniably something about the weepie that taps into storytelling traditions that predate cinema by a good long while.
He remembers being terrified of the Pieta at his church as a child: a mother cradling her dead adult son, face flashing with sorrow. Yet the image lodged in his mind's eye, and has kept him topped up with Catholic guilt ever since.
"I just remember feeling like a sinner for everything I did," he says. "It's like Adam and Eve eating the apple. What's wrong with that? You see the apple, you've got to eat it?"