Here’s a quote/excerpt by Stephen King from the book Kingdom of Fear: The World of Stephen King edited by Tim Underwood and Chuck Miller:
“A friend of mine said you know you’re being scary when you can feel the malevolent grin begin to creep up your face — and he’s right. Humor and horror are close together. Both come from the same aggressive impulse and in both cases we laugh or scream because we’re happy it isn’t us.
I don’t think anybody laughs at anything that isn’t inherently aggressive or hurtful or painful.
We have a history of being drawn to horror. Maybe it’s because we’re mortal and we keep trying to fit our minds around the concept of dying.”