Analyse

Psycho was an early use of the knife in horror but used it in a different way to recent films such as Halloween and Scream. Alfred Hitchcock is known for his clever way of portraying violence without showing huge amounts of macabre detail. Even in the famous shower scene, we barely see the knife as shadows are used cleverly so the viewer does not need to see such details to be scared. Even the idea that a "psycho" would come to murder a young woman for no reason is scary enough, especially for the time it was created. But, as audiences have changed more shock value is needed and the knife is certainly key to this. More recent films such as Halloween and Scream use the visual shock of a body being ripped open to scare the viewers while Psycho even shows minimal amounts of blood.
Audiences continue to ask for more in the way of shock, and directors seem to deliver. In the 1931 film Frankenstein censorship meant that the line in which Dr Frankenstein says "Now I know what it's like to be god!" was edited out because of the blasphemous nature of the line. Today, this line would be left unquestioned, it's not at all shocking to a viewer of today. In the case of the use of the knife, previously violence would only be implied. For example in Psycho shadow was used in a very intentional way, we never actually see the face of the murderer, but we do see his or her silhouette holding the knife. We also see shots of raised hands and the shape of the murderer. Although shadow is definitely still used in horror films today it is usually not used to hide graphic violence, instead directors of today like to focus on this detail of films.
Because of the accessible nature of the knife, it makes the viewer think about how, perhaps, anyone could do this. This idea is certainly played with in Scream when Ghost-face turns out to be two teenage characters Billy and Stu who are obsessed with Horror Films. They are rather 'average' people and this is scarier to the viewer. In Halloween the opening scene shows a 6 year-old Mike Myers killing his sister with a knife in her bedroom. The unnerving detail that it is a child committing such a horrific crime continues to play with the idea that no one is innocent. Also in Halloween Laurie's retaliation to the events is shocking. Stabbing him with any sharp object she can find shows us that this ordinary girl is also capable of killing another human being. Psycho takes another perspective on this idea, as Norman Bates has Personality Disorder he is rather unaware of what he has done, as even he himself believes it is someone else. But, for viewers this could be more unnerving and raises the question of  'What if I was in his position?'. Psycho plays with the idea of loss of control with in ones self, the murders are not organised as they were in Scream instead, they are simply a reaction to what has happened to Bates both in the past and more presently.