Imitation:
The meaning of imitation is the action of using someone or something as a model. This links to the effects of horror films as people may be influenced by what they see in horror films and mirror the actions in real life. For example "Natural Born Killings" has been the most influential horror film for copycat killings. An example of imitation is where a couple Sarah Edmonson and Benjamin Darras who took LSD then watched "Natural born killings" repeat then robbed and shot a convenience store clerk.
Catharsis:
This is the process of releasing emotion and this provides relief form these strong emotions. Watching films especially Horror's allows people a relief from the real world and the issues we face for example relationships or the economy. By watching a horror film you become scared and distressed allowing you to release your emotions which then gives you this pleasure as you are relieved from these negative emotions much like a cleanse.
Drip-Drip-Drip Effect (Desensitisation):
Sadistic images and violence which you commonly see in horror films are too easily available to younger audiences. This exposure to seeing violent acts for example in "psycho"in the shower scene, creates a drip-drip effect as these younger audiences have been exposed to this throughout their childhood so when they get to adult-hood they will be desensitised to this violence and will see it as "normal", meaning younger audiences behave in anti-social ways as they have been exposed to too much violence due to watching horror films.
Mean world syndrome:
Mean world syndrome was a termed developed by George Gerbner. It means that violence related content of mass media makes viewers believe the world is more dangerous than it actually is. So if people watch horrors like "scream" and "psycho" which involves a psycho killer murdering people, they will feel more vulnerable than they did before watching the film as they will think that there are murderers out there to get them which is highly unlikely.
No long term effects:
One great thing about horror films is that we all know that they aren't true in reality. Meaning when we watch them we might be scared however the "monster" cant actually hurt us as it's in the film and made up.