Psychoticism is one of the three traits used by the psychologist Hans Eysenck in his P-E-N model (psychoticism, extraversion and neuroticism) model of personality. Psychoticism is a personality pattern typified by aggressiveness and interpersonal hostility.
High levels of this trait were believed by Eysenck to be linked to increased vulnerability to psychosis such as schizophrenia. He also believed in a genetic basis to the trait, suggesting that blood relatives of psychotics would show high levels of psychoticism.
Psychoticism is conceptually similar to the constraint factor in Tellegen's three-factor model of personality. Psychoticism may be divided into narrower traits such as impulsivity and sensation-seeking. These may in turn be further subdivided into even more specific traits. For example, impulsivity may be divided into narrow impulsivity (unthinking responsivity), risk taking, non-planning, and liveliness.Sensation seeking has also been analysed into a number of separate facets.
Critics of the trait have suggested that the trait is too heterogeneous to be taken as a single trait. Costa and McCrae believe that agreeableness and conscientiousness (both which represent low levels of psychoticism) need to be distinguished in personality models. It has also been suggested that "psychoticism" may be a misnomer and that "psychopathy" or "Impulsive Unsocialized Sensation Seeking" would be better labels.
Psychoticism is believed to be associated with levels of dopamine. Other biological correlates of psychoticism include low conditionability and low levels of monoamine oxidase; beta-hydroxylase, cortisol, norepinephrine in cerebrospinal fluid also appear relevant to psychoticism level.