Definition of intertextuality:
Intertextuality is the shaping of texts' meanings by other texts. It can include an author’s borrowing and transformation of a prior text or to a reader’s referencing of one text in reading another. (Wikipedia)
Intertextuality is used in all types of media in order to draw on the knowledge of the audience so that they are mentally involved with the situation in a film. Many films use certain aspects and scenarios of other films but they are shown in a different way.
In the thriller ‘The Stepfather’ intertextuality is used to keep the audience engaged and aware of what is going on. In the scene where Susan stabs David in the neck with a piece of glass, David falls back into the bathtub pulling down the shower curtains in the process. The camera is directly focused on the shower curtain being pulled of the hooks. This is taken from another thriller film called ‘Psycho’. The scenario is very different because in the original scene from the psycho the victim is a woman and she dies in the bathtub and she drags the shower curtain as she falls.
Another example of intertextuality in ‘The Stepfather’ is when David is chasing Susan around the house. This is aspect was taken from the film ‘Fatal Attraction’ when Michael Douglas chases the woman around the house.