Development of Personality Functioning in the Context of Life Events: A Multi-Metric Approach

Dimensional conceptualizations of personality disorders, including assessing personality functioning, allow for thorough investigations of their development. Although evidence for when and why personality functioning changes is limited, life events are a promising candidate. As such, we used data from a year-long, four-wave study of young adults in Germany (N = 2,105; Mage = 25.38) to address three questions: (1) How does personality functioning normatively change? (2) How are life events related to personality functioning development? (3) Are there predictors of individual differences in event-related changes? We further tested the questions with four metrics: rank-order stability, mean-level change, within-person variability, and ipsative consistency. Results indicated personality functioning was moderately rank-order stable with little to no average change in other metrics over a year. However, the largely null average effects masked considerable heterogeneity in development, which life events partly accounted for. At the between-person level, events were associated with lower rank-order stability, greater mean-level increases, and less within-person variability. At the within-person level, events predicted mean-level decreases and increases in within-person variability. Notable heterogeneity emerged for event-related changes across metrics and these individual differences were explained by some demographic and event-related moderators. We discuss results within the scope of the development of pathological versus normal-range personality, utility of multiple metrics and levels of analysis, and importance of understanding what drives change for theory development and treatment.