Where 'Paranormal Activity' really comes into its own is its rhetoric of legitimacy - how it uses itself to authenticate itself, and thus furthers the pretence of being real.
Jeans and sneakers are definitely best for the haunted house. They usually won't let you in with a mask, even. It makes sense. They need to be able to tell who the rubes are. And, sneakers are good because the ground's uneven, and you're running and falling and stepping on the slower of your friends.
Making people laugh is so much more difficult than making them sad. Too much fiction defaults to the somber, the tragic. This is because sad endings are easy in comparison - happy endings aren't at all simple to earn, especially when writing to an audience jaded by them.
The slasher film is such a neat, self-contained genre.
We watch a romantic comedy because we want to cry, say, or an action movie so we can participate in heroics. Horror's different. It can hit you with a moment of revulsion so hard you might want to erase the last five minutes of your life, please.
There's no purer feeling in the world than being scared.
