Overview
- Researchers published a Nature paper on September 2, 2026 that pooled data from 46 cohorts and up to about 1.14 million people to run the largest genome-wide analysis of the Big Five traits.
- The study identified roughly 1,260 common genetic variants associated with one or more traits, including about 824 variants not previously reported.
- Even together the variants explain only a small to modest portion of variation in each trait, with reported estimates ranging roughly from about 5% to the mid-teens and polygenic scores predicting under about 4% in some tests.
- Within-family comparisons of siblings, twins, and parents showed little evidence that shared family environment drove the genetic associations, strengthening population-level causal inference.
- The genetic signals link personality profiles to many outcomes—such as conscientiousness with lower smoking and daytime activity, extraversion with early-pandemic COVID risk, and openness with urban residence—while measurement differences across cohorts, especially for agreeableness, point to work needed on cross-cultural harmonization and biological interpretation.