An actual writer of horror, Chris Angelis, responded with this lovely nugget: The reason for the phenomenon is how true horror is a result of our being unable to properly define reality. Whether our inability is a result of clearly supernatural elements or of ambiguity, the end result is the same-you come face-to-face with something that is incompatible with the reality you’re familiar with. The familiar becomes unfamiliar and you either can’t trust your senses, or you must accept that the laws of nature are changed. The reason we’re more afraid of nonviolent horror stories is because violence we can make sense of; nonrealism, we can’t. The reason is that we face the prospect of being unable to define our reality—who’s human and who isn’t, in this case.