A Genomic Window Into Lifespan Personality Development

Objectives: Across the lifespan, a person's genetics are associated with their personality traits. We will capitalize on recent advancements in personality genomics to test whether and how common genetic variants relevant to personality (i.e., polygenic indices (PGIs) for personality traits) are associated with trajectories of phenotypic personality development, both with age and in the context of life events. By linking genetics to personality through environment, we will substantiate mechanisms by which lifespan development occurs.

Study design: Observational; we will use existing data (the Health and Retirement Survey; HRS) to estimate longitudinal correlations between genetic profiles (PGIs) and personality trait development over time

Analysis plan:
1) Using genomic information from HRS participants, we will apply polygenic index weights (PGIs) from the forthcoming Revived Genomics of Personality Consortium (ReGPC) Genome-Wide Association Study (Schwaba et al., 2025) to assign each participant a PGI value for each of the Big Five personality traits (extraversion, agreeableness, conscientiousness, neuroticism, openness to experience).
2) Using multilevel models, we will estimate stable levels and change over time in the phenotypic Big Five personality traits (measured bi-yearly from 2006 onwards using the Midlife Development Inventory). Change will be operationalized as yearly development in the years before/after a stressful life event (measured with a life events questionnaire) and yearly age-graded development (measured in terms of change with age).
3) We will correlate PGI values with levels and change in the Big Five personality traits, to examine whether a person's personality-relevant genetics differentiate trajectories of development with age and in the context of life events

Across the lifespan, a person's genetics are associated with their personality traits. We will test whether and how genetic variants relevant to personality are associated with trajectories of personality trait development, both with age and in the context of life events. By linking genetics to personality through environment, we will substantiate mechanisms through which lifespan development occurs.