A massive genetic study offers one of the clearest pictures yet of how DNA contributes to personality, identifying genetic variants associated with five major personality traits. However, rather than discovering a handful of “personality genes”, the results show that 1,260 different variants are associated with aspects of personality, which are influenced by thousands of genetic differences, each having a small effect.
The study, published recently in Naturecombined data from 46 research groups, with sample sizes ranging from 611,000 to 1.14 million people according to which of the “Big Five” personality traits was analyzed: extroversion, agreeableness, conscientiousness, neuroticism or openness to experience. Of the 1,260 genetic variants identified, 824 were in regions not previously linked to the corresponding personality trait.
There is no single gene for being extroverted or conscientious. What we see instead are thousands of genetic differences that individually contribute in a small way, but collectively shape personality, alongside the many influences of a person’s environment. »
Henry R. Kranzler, MD, professor of psychiatry, Perelman School of Medicine, University of Pennsylvania, director of Penn’s Center for Studies of Addiction and study co-author
Personality is partly genetic, but not predetermined
Common genetic variants explain about 5 to 9 percent of the personality differences measured in the study’s main analysis. Researchers have estimated that more than 16,000 common genetic variants contribute independently to each of the five personality traits, illustrating how genetically complex personality is.
The genetic models also proved surprisingly consistent. The associations were generally similar across different age groups, Western geographic regions, personality tests, and how people described themselves or were rated by a significant other. Agreeableness showed less consistency than other traits.
The researchers went further by comparing people within families. These analyzes suggest that most genetic associations cannot be explained by shared environmental factors among family members, a potential source of bias in studies linking genetics to behavior.
Links between personality and health
The team also discovered genetic overlap between personality traits and a wide range of behaviors and health conditions, including mental health problems, substance use and physical health. For example, genetic profiles associated with neuroticism were associated with increased risk in the psychiatric conditions studied, while conscientiousness showed genetic associations with less substance use and more frequent exercise.
Associations are at the group level and cannot be used to make predictions about individuals. The researchers found that genetic measures only predicted behavior to a small extent and explicitly cautioned that they could not predict an individual’s future behavior. Personality, in its entirety, reflects both genetic and environmental influences.
“These findings give us a new tool to study why personality is linked to so many aspects of health and behavior,” Kranzler said. “But they also reinforce an important point: our DNA influences, but does not dictate, our personality or our future.“.
The researchers say larger studies encompassing more ancestral and cultural origins will be important in determining the extent to which these genetic models apply consistently across populations.
Source:
Journal reference:
Schwaba, T., and others. (2026). Robust inference and correlations from genetic associations with personality. Nature. DOI: 10.1038/s41586-026-10992-9. https://www.nature.com/articles/s41586-026-10992-9
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