Date of Award
7-12-2023
Degree Name
Doctor of Philosophy (PhD)
Degree Type
Dissertation
Abstract
Decades’ worth of research has identified replicable, average patterns of normative personality development across the lifespan. Underlying these findings lie a few assumptions, however, and work seeking to provide incremental knowledge seems to have yet offered a clear path forward. This impasse in progress, in conjunction with studies highlighting the complexity of personality, would suggest these assumptions are perhaps untenable. The current study uses five longitudinal datasets (N = 128,345) to examine personality development using mixed effects location scale models. This permits there to be individual differences in within-person residual variability, or sigma, around trajectories – thereby testing if standard models that assume this is homogeneous, unsystematic noise with no implications are appropriate. In doing so, I investigate if there are individual differences in longitudinal within-person variability for trajectories of the Big Five traits; if there are variables associated with this heterogeneity; and if person-level sigma values can predict an outcome, above and beyond the effects of trait levels and changes. Results indicated that, across all models, there were meaningful individual differences in sigma – the magnitude of which was comparable to that of intercepts and slopes. Variables of empirical and theoretical importance in personality development were further associated with this longitudinal within-person variability. Lastly, person-level sigma values proved to have robust predictive utility. Collectively, these results underscore the presence and degree of individual differences in longitudinal within-person variability; their potential for uniquely advancing knowledge; and the necessity of empirically quantifying and theoretically incorporating this individual difference in future personality development research.
Language
English (en)
Chair and Committee
Joshua Jackson
Recommended Citation
Wright, Amanda Jo, "Modeling Variability in Personality Development: Quantifying, Explaining, and Examining the Predictive Utility of Person-Specific Variance Around Personality Trajectories" (2023). Arts & Sciences Electronic Theses and Dissertations. 2996.
https://openscholarship.wustl.edu/art_sci_etds/2996