UCSD psych researchers Jonathan D. Leavitt and Nicholas J. S. Christenfeld have published a paper called Spoilers Don't Spoil Stories in Psychological Science, in which they systematically study the effect of spoilers on audiences' appreciation of stories. As the title suggests, they found that despite subjects' stated sensitivity to spoilers, having stories spoiled for them didn't undermine their enjoyment of stories — in fact, it sometimes enhanced it. Ty Burr has more:
No matter how much we claim to love that uncertainty, Leavitt and Christenfeld's study indicates that spoilers provide some psychological relief, a way of dipping our toes in the ocean of fiction before diving in. Not knowing where a compelling story is going creates anxiety, and it's that anxiety, Leavitt believes, that fuels the secret itch to cheat. "There are emotions we don't like feeling in real life," he says. "We feel them watching a movie, but without the anxiety it's not as difficult to cope with. We feel safer. I feel that's even more the case if you know where the story's going — there's not the dread or the fear that could spill over a little bit into real life."
If a work of fiction is particularly well crafted — like "The Godfather" or like one of Leavitt's recent favorite reads, Richard Russo's "Straight Man" — it's possible to fool ourselves into a temporary not-knowing while revisiting it, to lose ourselves in the story all over again even as part of our brains breathes a sigh of relief at knowing where the guard rails are. From that perspective, an unspoiled story may be just a hurdle we have to surmount in order to appreciate it later in greater comfort, the way we have to get used to certain foods, like artichokes or oysters.
I don't mind spoilers at all, and I find extreme spoiler-aversion pretty tedious. Some people act like they have a deadly nut allergy to spoilers, one which will cause their throat to close and suffocate them should they happen on the faintest trace of spoil. It's all a bit precious and drama-y.