Funny, but few days ago I found a book called THE ROUGH GUIDE TO HORROR MOVIES. I had a little read through and I found some information interesting.
"So what is horror?
This strong emotion, one of the oldest and deepest of humankind, is what we feel when anything frightens us or promotes fear or terror."
This made me think about the purpose of making thrillers... I think that thrillers as well as other movies are meant to entertain us, in a level we feel engaged and should literally be out of our seat, wanting to know what will happen. Watching movie and feeling frigtened makes us feel entertained. If it didn't, why would these type of movies be watched for so many years? (First horror movie was made in 1895- Haunted Castle, it was only two minute movie, but this was the start of suspense)