Hubert Suszek ^1* Maciej Kopera ² Andrzej Jakubczyk ²

• ¹ Faculty of Psychology, University of Warsaw, Warsaw, Masovian, Poland
• ² Department of Psychiatry, Medical University of Warsaw, Warsaw, Masovian, Poland

This research identifies and explores two distinct modes of self-experience and their influence on psychological openness. We distinguish between the unitary self mode, where individuals perceive themselves as cohesive, stable entities, and the multiple self mode, where they recognize their diverse, context-dependent aspects. These modes represent fundamentally different ways of experiencing and organizing self-knowledge that can be situationally activated.We hypothesized that activation of the multiple self increases psychological openness. In five experiments (N = 989), we demonstrated that induction of the multiple self enhanced various dimensions of openness compared to induction of the unitary self. This effect was consistently observed across various domains of openness: openness as a state (Study 1, N = 204), openness to change (Studies 3 and 4, N = 230 and N = 184), range of values (Studies 2 and 3, N = 212 and N = 230), psychological mindedness and decentering (Study 5, N = 159). Results consistently showed moderate effect sizes (d = 0.31-0.44) across different operationalizations of both the multiple self induction and openness measures. These findings indicate that the way in which individuals organize their self-knowledge has important implications for their cognitive and experiential flexibility, contributing to our understanding of personality plasticity and development.