Horror Films over the last 60 years have went through a plethora of changes in order to stay fresh and relevant to the open minded and often critical horror target audience. Although rehashing old ideas is considered an instant draw, (take for example the remakes of Halloween in 2007 and Nightmare on Elm Street in 2010) the makers of the films must find new ways to wow, entertain, and most of all frighten the viewers. Society as a whole is constantly changing with on growing technology and post modern thinking; horror films noticeably change their creative direction according to current fears or situations in Western society.
Take for example the attitudes of civilians post WWII. When people discovered the nuclear bomb and its effect on the world, people began to be afraid of radiation and its effect on wildlife etc. This lead to a series of horror films depicting insects and various animals suffering from radiation poisoning killing civilians. Godzilla and Them! were among the most popular. Many other changes have ushered since then and the media must find new and unique ways to terrify the audience.