Idiographic momentary profiles of personality facets

Personality psychology has long focused on between-person differences, often neglecting the dynamic, idiographic nature of personality as it unfolds in everyday life. This study introduces idiographic momentary profiles-person-specific clusters of Big Five Inventory-2 facet states-estimated using Gaussian finite mixture modeling. Drawing on experience-sampling data from two independent undergraduate samples (N = 245; 15,833 total surveys), we demonstrate that individuals exhibit unique, multivariate personality state patterns that vary across time and situations. Findings reveal that (a) most individuals express multiple distinct profiles, (b) profile distinctiveness reflects both level and pattern differences, and (c) situation characteristics (i.e., Situational Eight DIAMONDS items) predict momentary profile expression. These results challenge static trait and typological approaches by highlighting the complexity and contextuality of personality dynamics. Our findings underscore the value of idiographic methods in advancing personality theory and modeling, offering a foundation for capturing the full scope of personality variability in daily life.expression. These results challenge static trait and typological approaches by highlighting the complexity and contextuality of personality dynamics. Our findings underscore the value of idiographic methods in advancing personality theory and modeling, offering a foundation for capturing the full scope of personality variability in daily (PsycInfo Database Record (c) 2026 APA, all rights reserved).