Exploring the blurred boundaries between self and other: self-other differentiation links pathological narcissism and paranoia

Recent empirical contributions and clinical observations indicate that individuals high in narcissism are prone to experiencing paranoid presentations. However, previous studies are limited in number, and they show inconsistent findings. Moreover, little is known about the underlying mechanisms responsible for this tendency. The present study investigated the relationship between pathological narcissism and paranoid presentations by examining whether impaired self-other differentiation explains this relationship. A sample of 750 nonclinical participants (females: N = 614, 81.9%) with a mean age of 36.8 years (SD = 13.0) completed self-report questionnaires assessing pathological narcissism based on the Trifurcated Model, several dimensions of paranoid presentations, and the level of self-other differentiation. Results of mediation models revealed that narcissistic neuroticism and antagonism were associated with a wide range of paranoid presentations, ranging from less severe to more severe forms, and that impaired self-other differentiation partially accounted for these presentations. In contrast, agentic extraversion appeared to play an adaptive role, mitigating paranoid presentations due to greater self-other differentiation levels. Our contribution clarifies which trait components of narcissism are related to paranoia and establishes the initial groundwork for understanding how impairment in self-other differentiation may contribute to the relationship between pathological narcissism and paranoid experiences.