Why do we watch Scary Thrillers?

We watch scary things so we can purge(cleanse) and experience catharsis.

Aristotle
384 BC - 322 BC
We are drawn to violent, scary & negative imagery or experiences to release pent up feelings of aggression.

Dolf Zillmann
Excitation and Transfer Theory
Experiencing scary & negative situations creates an intensifying amount of positive feelings once those feelings of negativity are removed.

Glenn D. Walters
For films to be scary they must have tension & suspense. They must be unrealistic. They must employ the use of the micro elements and have a narrative.