It might feature such thought-stretching concepts as time travel and warp drives, but reading science fiction actually makes you read more “stupidly”, according to new research.

In a paper published in the journal Scientific Study of Literature, Washington and Lee University professors Chris Gavaler and Dan Johnson set out to measure how identifying a text as science fiction makes readers automatically assume it is less worthwhile, in a literary sense, and thus devote less effort to reading it. They were prompted to do their experiment by a 2013 study which found that literary fiction made readers more empathetic than genre fiction.

Their study, detailed in the paper The Genre Effect, saw the academics work with around 150 participants who were given a text of 1,000 words to read. In each version of the text, a character enters a public eating area and interacts with the people there, after his negative opinion of the community has been made public. In the “literary” version of the text, the character enters a diner after his letter to the editor has been published in the town newspaper. In the science fiction version, he enters a galley in a space station inhabited by aliens and androids as well as humans.

After they read the text, participants were asked how much they agreed with statements such as “I felt like I could put myself in the shoes of the character in the story”, and how much effort they spent trying to work out what characters were feeling.

Gavaler and Johnson write that the texts are identical apart from “setting-creating” words such as “door” and “airlock”: they say this should have meant that readers were equally good at inferring the feelings of characters, an ability known as theory of mind.

This was not the case. “Converting the text’s world to science fiction dramatically reduced perceptions of literary quality, despite the fact participants were reading the same story in terms of plot and character relationships,” they write. “In comparison to narrative realism readers, science fiction readers reported lower transportation, experience taking, and empathy. Science fiction readers also reported exerting greater effort to understand the world of the story, but less effort to understand the minds of the characters. Science fiction readers scored lower in comprehension, generally, and in the subcategories of theory of mind, world, and plot.”

Readers of the science fiction story “appear to have expected an overall simpler story to comprehend, an expectation that overrode the actual qualities of the story itself”, so “the science fiction setting triggered poorer overall reading”.

The science fiction setting “appears to predispose readers to a less effortful and comprehending mode of reading – or what we might term non-literary reading – regardless of the actual intrinsic difficulty of the text”, they write.

Gavaler said he was moved to undertake the study after being irritated by the 2013 empathy research. Carried out by psychologists David Comer Kidd and Emanuele Castano, it gave participants extracts of texts by writers such as Danielle Steel or Gillian Flynn, identifying these as “genre” fiction, or extracts of more “literary” works, then analysing how accurately readers could identify emotions in others. The literary readers, they found, were better at doing this.

Gavaler said: “I think their study has so many problems. I also teach creative writing and contemporary fiction with a particular interest in hybrid ‘literary genre’ works, so I was especially annoyed by how their category divisions weren’t accurate. For example, my short story Is was published in the literary journal New England Review and then later in the genre anthology Best American Fantasy.”

The academic, who is also the author of a guide to superhero comics, said that he and Johnson were “surprised by how sharp the results were” on genre in their own study, which only alters words and phrases in the texts to produce their different settings.

“While this wouldn’t be true of all readers, for those who are biased against SF, thinking of it as an inferior genre of fiction, they assume the story will be less worthwhile, one that doesn’t require or reward careful reading, and so they read less attentively. This then lowers their scores on objective comprehension tests because they miss so much. Interestingly, they don’t even realise it, because they still report that the story required less effort to understand. It’s a self-fulfilling bias – except we can now show objectively that the weakness is with the reader, not the story itself,” said Gavaler.

“So when readers who are biased against SF read the word ‘airlock’, their negative assumptions kick in – ‘Oh, it’s that kind of story’ – and they begin reading poorly. So, no, SF doesn’t really make you stupid. It’s more that if you’re stupid enough to be biased against SF you will read SF stupidly.”

Gavaler said that in the future, he would like to test readers’ responses to longer texts and to other genres, exploring whether “genre markers” such as a cowboy hat or a sorcerer’s wand would have similar effects on readers. He was not, he added, tempted to move away from genre in his own writing. “The study makes me want to blend genres even more. I’m working on a short story that could be categorised as a literary science fiction horror western. I have a novel manuscript that’s a literary YA supernatural thriller. Another is a literary mystery about superhero comics. The possibilities are exciting and endless,” he said.

“I was paradoxically pleased by the results … In an ideal world, there would be no bias. But if it exists, and it does, it’s useful to expose it.”

Science fiction author Jon Courtenay Grimwood said that “the problem is a very basic one – people give an art form the care and attention they think it deserves. (Or perhaps have been told it deserves.) You get out of a book what you bring to it. Well, most books.”