Why do we watch horror movies?

  As Halloween approaches, horror themes are inevitably seen more and more in everyday life. Houses will be decorated with spooky designs, and there will be horror movie marathons going on television. When I saw on TV the Friday the 13th marathon starting this weekend,  I began to wonder why is it that so many people likes watching horror movies. Horror movies range from blood splattering slasher films to silent chilling supernatural films. As a movie fan myself, I have watched many kinds of horror movies and I do enjoy watching them. In this article, it is said that some people watch it simply for the physiological ride and others watch to understand the archetypal fears, what the population fears as a whole.
I think the second reason given in the article, the archetypal fear, represents America in a way. As the article states, horror movies after 9/11, which affected the country as a whole, were mostly centered on the them of torture which could have meant for the audience to comprehend the incident. Another example, the article says, zombie movies might have gotten popular because of the spread of influenza. I think this theory makes sense because naturally we all want to be in a large group, so that we can feel safe, and fear is one medium that will have us connected because fear is shared as a common feeling by many people.
Why do you think people watch horror movies?