[UC San Diego psychologists Nicholas Christenfeld and Jonathan Leavitt] ran three experiments with a total of 12 short stories. Three types of stories were studied: ironic-twist, mystery and literary. Each story—classics by the likes of John Updike, Roald Dahl, Anton Chekhov, Agatha Christie and Raymond Carver—was presented as-is (without a spoiler), with a prefatory spoiler paragraph or with that same paragraph incorporated into the story as though it were a part of it. Each version of each story was read by at least 30 subjects. Data from subjects who had read the stories previously were excluded.
Subjects significantly preferred the spoiled versions of ironic-twist stories, where, for example, it was revealed before reading that a condemned man’s daring escape is all a fantasy before the noose snaps tight around his neck.
The same held true for mysteries. Knowing ahead of time that Poirot will discover that the apparent target of attempted murder is, in fact, the perpetrator not only didn’t hurt enjoyment of the story but actually improved it.
Subjects liked the literary, evocative stories least overall, but still preferred the spoiled versions over the unspoiled ones.