In development psychology, Melanie Klein proposed a "(psychic) position theory" instead of a "(psychic) stage theory."
In object relations theory, the paranoid-schizoid position is a state of mind of children, from birth to four or six months of age.
Melanie Klein has described the earliest stages of infantile psychic life in terms of a successful completion of development through certain positions. A position, for Klein, is a set of psychic functions that correspond to a given phase of development, always appearing during the first year of life, but which are present at all times thereafter and can be reactivated at any time. There are two major positions: the paranoid-schizoid position and the subsequent depressive position. The earlier more primitive position is the paranoid-schizoid position and if an individual's environment and up-bringing are satisfactory, she or he will progress through the depressive position.
The paranoid-schizoid position is considered the state of mind of children from birth to four or six months of age. Although this position develops into the next position, it is normal to move back and forward between the two positions although some people operate in the paranoid schizoid position for much of the time. As one of the originators of Object Relations theory, Klein sees emotions as always related to other people or objects of emotions. Relations during these first months are not to whole objects but only to part objects, such as the breast, the mother's hands, her face etc.
Paranoid refers to the central paranoid anxiety, the fear of invasive malevolence. This is experienced as coming from the outside, but ultimately derives from the projection out of the death instinct. Paranoid anxiety can be understood in terms of anxiety about imminent annihilation and derives from a sense of the destructive or death instinct of the child. In this position before the secure internalisation of a good object to protect the ego, the immature ego deals with its anxiety by splitting off bad feelings and projecting them out. However, this causes paranoia. Schizoid refers to the central defense mechanism: splitting, the vigilant separation of the good object from the bad object.
Klein posited that a healthy development implies that the infant has to split its external world, its objects and itself into two categories: good (i.e., gratifying, loved, loving) and bad (i.e. frustrating, hated, persecutory). This splitting makes it possible to introject and identify with the good. In other words: splitting in this stage is useful because it protects the good from being destroyed by the bad. Later, when the ego has developed sufficiently, the bad can be integrated, and ambivalence and conflict can be tolerated.