RESUMEN
Narcissistic traits are traditionally viewed as consistent similar to the mirrorlike self-reflection of Narcissus in the water. However, evidence suggests that state levels of narcissism are more dynamic than previously believed. The current research explored fluctuations within and between grandiose and vulnerable narcissism in daily life. We investigated whether individuals' levels of grandiosity and vulnerability (a) vary, (b) are instable, and (c) display inertia and cross-lagged effects in their daily narcissistic expressions. Participants (N = 253; Mage = 22, 85% female) completed grandiose and vulnerable narcissistic trait questionnaires. Using ecological momentary assessment, they further completed up to 60 grandiose and vulnerable narcissistic state questionnaires over 6 days. The results showed that higher grandiose and vulnerable narcissistic traits led to more within-person variability within their corresponding states. Additionally, higher grandiose leadership/authority traits related to greater vulnerable within-person variability, while grandiose self-absorption/self-admiration reduced this. Similarly, all narcissistic traits, except for exploitativeness/entitlement and egocentrism, were positively related to increased instability in their corresponding state. Further, both grandiose and vulnerable narcissistic states demonstrated significant inertia, that is, lingering narcissistic endorsements within their own states. Overall, though the effect sizes were limited, the results showed that grandiosity and vulnerability include time-variant states that are intertwined and need to be acknowledged as additional moving, dimensional constructs. (PsycInfo Database Record (c) 2024 APA, all rights reserved).