Moving Beyond the “Candidate Event Crisis”: Estimating the Combined Effects of 25 Life Events on Personality Trajectories

Life events are theorized to play an important role in personality development (Roberts & Nickel, 2017). Over the past two decades, research on event-related personality change has largely relied on a “candidate event approach,” estimating the effects of a small number of major life events modeled in isolation. Yet, recent meta-analytic evidence suggests that individual life events—even those that are intuitively impactful—tend to have very small effects on trait change (e.g., getting married, retiring; Bühler et al., 2024). People’s lives, however, consist of far more than a handful of “big days”; instead, they comprise a rich collection of experiences that may collectively shape who people become. Drawing inspiration from molecular behavior genetics—which moved beyond candidate gene studies towards polygenic models—the present study used analogous methods to model the poly-experiential nature of personality change. Using data from 4,904 adults who completed monthly assessments of the Big Five traits and 25 life events over two years, we conducted a poly-experience index (PXI) analysis and an Experience-Wide Complex Trait Analysis (ECTA), estimating the combined influence of many life events on trait change. PXIs accounted for 1-2% of the variance in trait change for neuroticism and conscientiousness—modest in absolute terms, but between 8 and 16 times greater than the variance explained by any single, “candidate” event. ECTA accounted for 1-2% of the variance in change for all Big Five traits except agreeableness. Implications of these findings for future research on life events and personality development are discussed.