What did the largest ever genetic study of personality—combining Big Five questionnaire and DNA data from about 1.14 million people across 46 cohorts—find about the 1,260 associated genetic variants (including 824 newly identified ones), the very small share of personality variat

The study found that personality has a highly polygenic genetic component: many DNA variants are statistically associated with Big Five traits, but each has a minuscule effect. The results help explain population patterns and trait-related life outcomes; they do not diagnose, determine, or reliably reveal any one person’s personality. 236

Core genetic findings

• Across 46 cohorts and 611,037 to 1.14 million participants, the researchers identified 1,260 lead variants associated with the Big Five—extraversion, agreeableness, conscientiousness, neuroticism and openness—including 824 variants in previously unreported regions. 23
• The associations were broadly consistent across settings and measures, supporting the conclusion that they reflect real, distributed genetic influences rather than a handful of “personality genes.” 23
• Common variants collectively explained about 4.8%–9.3% of measured variation in each trait; after accounting for typical questionnaire unreliability, estimates were roughly 9.3%–13.3%. 23
• Polygenic scores were still poor individual predictors: a score summarizes many tiny population-average associations, leaving the overwhelming majority of a person’s measured personality variation unexplained. 236

Links with health and life outcomes

• The genetic tendencies associated with the traits overlapped with genetic tendencies linked to health, well-being and broader life outcomes, which may help explain why personality itself predicts differences in those domains. 27
• The question’s more specific outcomes—longevity, education, careers, early-pandemic COVID-19 risk, and migration toward cosmopolitan places—should be understood as genetic correlations or associations, not proof that personality DNA directly causes them. The available evidence here does not provide the direction, size, or trait-specific details for each association. 23
• In particular, genetic links to education and mortality can reflect correlated traits, social environments, assortative mating, and other pathways—not a simple genetic route from personality to schooling or lifespan. Evidence from other work shows polygenic associations with mortality, but it does not establish personality-gene causation. 8

Family-based evidence and its limits

• The study included within-family analyses involving siblings and twins; broadly similar estimates within families were intended to reduce concern that the main results merely reflect population stratification or the shared upbringing of families. 23
• This strengthens the inference that inherited DNA differences contribute to personality differences, because siblings are compared against each other while sharing much of their family environment. But it does not make every downstream association causal, nor does it eliminate all environmental or gene–environment pathways. 23
• Separate twin COVID-era research found substantial genetic contributions to stable individual differences in psychological responses, while also finding that major environmental disruption did not erase those differences. That is compatible with genetic influence, not genetic determinism. 45

Why this is not a personality test from DNA

• The variants are common, numerous, and individually tiny in effect; their combined predictive power is limited even in the populations used for research. 236
• Personality questionnaires are imperfect measures, and personality is also shaped by development, experiences, relationships, culture, circumstances and chance. 23
• Thus the proper conclusion is population-level: people with certain genetic profiles may, on average, differ slightly in trait scores or correlated outcomes. It is not valid to infer that a particular person “has” a given personality, will attain a certain education or career, move to a city, contract COVID-19, or live longer based on DNA alone. 123