Does Eysenck's personality model capture psychosis-proneness? A systematic review and meta-analysis

Eysenck's model of personality (PEN) was one of the most influential personality models in the 20th century. A unique characteristic of this model is the claim of psychosis-proneness being incorporated into it as one of its three basic traits - Psychoticism. The main goal of this systematic review and meta-analysis is to find out the associations between PEN traits and a diverse set of operationalizations of psychosis-proneness (PP). We set the benchmark for assuming their distinctness to a correlation coefficient amounting to 0.40. A systematic review has been conducted, yielding 350 correlations of interest. By computing inverse sampling variance weighted mean correlation coefficients, we found the following associations between psychosis-proneness and Psychoticism, Extraversion, and Neuroticism, respectively: 0.21, -0.09, and 0.30. All prediction intervals around the three mean effect sizes do include zero, suggesting that psychosis-proneness is only marginally captured by the PEN model. Moderator analyses further demonstrated this distinctness and the lack of phenotypic validity of the Psychoticism scale/construct.