Spoiler Alert: Stories Not Ruined if Ending Revealed Test subjects actually liked a story more if they weren't surprised.

Aug. 12, 2011  -- This story -- spoiler alert! -- has a happy ending. If it were a suspense novel, would knowing that make you enjoy it less? To their surprise, psychology researchers found that people actually rated stories higher if they knew how they came out.

Whoa -- can ruining the surprise make a story more enjoyable? That's what Nicholas Christenfeld and Jonathan Leavitt found, and Christenfeld says he was at first stumped. Leavitt is getting his doctorate in psychology at the University of California at San Diego, and Christenfeld is a professor there.

"I was surprised by the finding," Christenfeld said. "I've spent my life not looking at the end of a book." He and Leavitt had 300 volunteers read 12 short stories, including mysteries or tales with surprise endings by the likes of Agatha Christie, John Updike and Anton Chekov, and rated them on a scale of 1 to 10. Almost without fail, and by sizeable margins, the readers rated them more highly if the researchers inserted copy near the beginning, giving away how the tales would come out.

"You get this significant reverse-spoiler effect," Christenfeld said in an interview with ABC News. "It's sort of as if knowing things puts you in a position that gives you certain advantages to understand the plot."

The researchers say their study did not give direct evidence to explain why people didn't mind having a surprise spoiled, but Christenfeld said he's thought about it and has some ideas. Perhaps, he said, people enjoy a good story as much as a good twist at the end. Even if they know how it comes out, they'll enjoy the journey as much as the destination.

"Writers use their artistry to make stories interesting, to engage readers, and to surprise them," Leavitt and Christenfeld said in their paper, to be published in the journal Psychological Science. "But giving away these surprises makes readers like stories better. This was true whether the spoiler revealed a twist at the end -- that the condemned man's daring escape was just a fantasy before the rope snapped taut around his neck -- or solved the crime -- that Poirot will discover that the apparent target of attempted murder is in fact the perpetrator."

So -- spoiler alert! -- stand forewarned that at the end of "Hamlet," the young prince says, "I am dead, Horatio." Or, if you prefer a slightly different genre -- skip this paragraph if you don't know! -- Harry Potter is still alive at the end of the series.

People have heard by now. Nevertheless, "Harry Potter and the Deathly Hallows, Part 2" has been the biggest movie of the summer so far. And "Hamlet" (the play, if not the prince) is, well, immortal.

"In Shakespeare's plays there's no hiding the ending," said Christenfeld. "When you start 'Hamlet,' you know it's a tragedy."

The researchers say they're thinking about follow-up studies, though a controlled test of responses to films is more difficult than one involving short stories. But they've come away believing that surprise may be overrated.

"Other intuitions about suspense may be similarly wrong," they conclude, "and perhaps birthday presents are better wrapped in transparent cellophane."

Christenfeld chuckled when we spoke with him. "Maybe jokes are the one thing you can spoil."