An all-or-nothing thinking turns into darkness: Relations between dichotomous thinking and personality disorders

Dichotomous thinking is an individual's propensity to think terms of binary opposition. While this thinking style may be useful for quick decision-making, some clinical psychologists have indicated that such a style is related to personality disorders. Oshio (2009) revealed that the Dichotomous Thinking Inventory (DTI) has significant positive correlations with borderline personality and narcissism. This study examines whether dichotomous thinking is associated with cluster A, B, and C personality disorders. The participants comprised 152 Japanese undergraduates (84 male and 68 female). They completed the DTI and Ten Personality Styles scale (10 PesT; Nakazawa (2006)), developed from the definitions of personality disorders the DSM-IV. Structural equation modeling supported the hierarchical factor structure of personality disorders. The dichotomous thinking effects "cluster" level of disorders more than other levels. The results indicated that thinking dichotomously may lead to wide-ranging personality disorders.