Nicholas Christenfeld, a University of California, San Diego professor of social psychology, along with Jonathan Leavitt, a PhD candidate at UC San Diego studying psychology, organized an experiment where volunteers were given three stories of different genres, written by well-known authors such as John Updike and Anton Chekhov. One of those stories had a spoiler in a separate paragraph, another had the spoiler worked into the opening paragraph and a last one did not have any hint of the ending. Participants typically enjoyed the stories with the spoiler at the very beginning the most, even when the story had an unexpected twist ending or was a murder mystery.
There are a few plausible explanations for this outcome. Christenfeld and Leavitt conclude that viewers are more likely to enjoy the actual story when they know the ending rather than waiting impatiently to find out that so-and-so killed so-and-so with the this-that-and-the-other-thing.