Horror movies appeal because humans like to feel grossed out and entertained pleasurably at the same time. There's a payoff in coexperiencing two conflicting emotions.
But I think the author glosses over a point made in the study that I think needs further examination:
They suggest that people who enjoy the yuck-yay feeling of horror movies are masters at psychological framing and distancing. Horror viewers who have the most fun are also the ones who are most convinced that what they're watching isn't real.
The study circumstances were quite artificial in at least one regard (the other being not using a more recent crop of horror films). The study subjects were repeatedly reminded that the movie characters were movie characters:
The researchers proved this point by showing people horror films alongside biographies of the actors playing the main characters, constantly reminding viewers that these were just movies and the “victims” were playing roles. Even viewers who normally avoid horror movies reported that they were a lot more comfortable and had some fun when they were reminded that the action was staged.
Do movie goers separate the fantasy as well under normal viewing conditions? Could not separating it as well contribute to less empathy and more desensitization to violence rained upon others? How would that translate into future actions in “the real world”? I don’t mean necessarily making them more violent toward others, although without further study I am not sure you can say one way or the other, but does it make us less empathetic or sympathetic toward others? Does it make us “numb” toward violence, less aware and more accepting? And, if so, what is that effect on society? Does it make them less “reachable” with “shock” messages based on avoidance of violence/injury?
That is the information I would like to see. It is my gut-feeling that these increasingly violent and disgustingly graphic (but not really realistic) movies have to be “bad” as a steady diet and maybe even if just consumed episodically.