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DATE: September 15, 2026 at 06:00AM
SOURCE: PSYPOST.ORG** Research quality varies widely from fantastic to small exploratory studies. Please check research methods when conclusions are very important to you. **
-------------------------------------------------TITLE: Massive study of over a million people identifies hundreds of genetic variants linked to personality
A massive genetic analysis has identified hundreds of specific DNA variations tied to human personality. The findings suggest that the genetic basis of personality is highly consistent across different populations and is not heavily skewed by a person’s family environment. The research was published in Nature.
Personality is typically understood through the framework of the “Big Five” traits. These include extraversion (sociability and energy), agreeableness (compassion and trust), conscientiousness (organization and responsibility), neuroticism (anxiety and volatility), and openness to experience (curiosity and imagination). Decades of research show that these traits are relatively stable over a person’s life and influence major outcomes like physical health, career success, and mental well-being.
Scientists know that genetics play a role in shaping personality. However, the exact genetic mechanisms remain complex, and many previous studies have struggled to pin down how individual variations in our DNA correspond to specific traits. To find these links, researchers use a technique called a genome-wide association study, which scans the entire genetic code of many people to find common single-letter changes in DNA that appear more frequently in individuals with certain traits.
The research team, led by Ted Schwaba of Michigan State University alongside Michel G. Nivard and Elliot M. Tucker-Drob, wanted to test the robustness of these genetic associations. They specifically aimed to determine if the genetic markers linked to personality actually reflect direct biological inheritance. For example, a 2022 study indicated that genetic links for some social behaviors, such as educational achievement, tend to be inflated by the shared environment that parents create for their children. The authors sought to see if personality genetics suffer from this same type of environmental confounding.
The researchers gathered data from 46 different study cohorts spanning multiple countries. The total sample size ranged from roughly 611,000 to over 1.14 million participants for each of the Big Five traits. Participants provided DNA samples and completed validated surveys to assess their personalities.
By pooling this massive amount of data, the researchers identified 1,260 specific locations in the human genome that are associated with the Big Five traits. Of these locations, 824 had never been linked to personality variation before. Individually, each genetic variant has a tiny effect on a person’s character. Altogether, these common variants explain between 4.8 percent and 9.3 percent of the variance in personality across the population.
The genetic signals were highly consistent across different groups. The researchers found similar genetic patterns across populations in the United States, Europe, and Australia, as well as across different age groups. The genetic links also remained stable regardless of the specific survey used to measure personality, and even when a person’s traits were rated by a close friend instead of through self-report.
To test whether family environments were skewing the results, the scientists looked at genetic data from thousands of siblings. Because siblings share the same parents and similar upbringings, comparing siblings isolates the direct effect of their differing genes. The researchers found that the genetic associations for personality barely changed when looking within families. This provides evidence that the genetic architecture of personality is driven mostly by direct biological inheritance rather than the social environments parents create for their children.
The team also looked at whether people choose partners with similar genetics for personality. While a 2023 meta-analysis, a research method that combines data from many different studies to find common results, found that partners often share similar behavioral traits, this new study found only minimal genetic similarity for personality between spouses. This indicates that people do not typically sort themselves into relationships based on genetic profiles associated with the Big Five traits in any major way.
To understand how personality shapes the human experience, the researchers used a statistical technique that relies on genetic data to test for cause-and-effect relationships. They found evidence that personality traits have widespread effects on behaviors and physical health. For example, having genetic variants linked to higher conscientiousness was also associated with a lower body mass index and a reduced likelihood of starting smoking. Similarly, a genetic profile associated with higher neuroticism was linked to a lower chance of healthy aging.
The analysis also identified some effects working in the opposite direction. The results suggest that factors like educational attainment and changes in body mass index might cause shifts in a person’s average levels of certain personality traits. This supports the idea that life experiences and physical health continuously interact with our biology to shape who we are over time.
“To me it is incredibly exciting to see such a huge genome-wide association study of personality,” Jasmin Wertz, a researcher at the University of Edinburgh who was not involved in the study, told PsyPost. “Personality traits are some of the most fundamental psychological axes on which people differ, but until now we did not have such a large-scale genomic investigation of these traits, similar to what has already been done for other key traits and behaviors. I think it is also impressive from a team science perspective, because the study brings together so many investigators and cohorts to advance the science.”
“This paper offers a compelling illustration of how complex human traits, like personality, are shaped by many many genes, and each one makes a small contribution to a person’s thoughts, feelings, and behaviors,” said Paul W. Eastwick, a professor in the Department of Psychology at the University of California, Davis who was not involved in the research. Eastwick, the author of Bonded by Evolution and host of the Love Factually podcast, added, “There is no single ‘gene for’ something as complex as personality; instead, genes play an important role in the aggregate.”
Wertz noted that the massive sample size and the inclusion of different measurement contexts give the results considerable weight. “The findings appear very robust,” she said. “The authors also add a within-family analysis, which shows that the genetics associated with personality are predictive even within siblings raised in the same family, and this analysis helps rule out many of the possible confounding influences that may be present when analyzing unrelated individuals.”
She also pointed out how the findings on romantic partners build on existing knowledge. “One notable finding was that assortative mating the tendency of people to pick romantic partners they resemble was very low in this study,” Wertz explained. “It doesn’t necessarily challenge previous findings, because the degree of spousal similarity in personality is not that high in other samples either, but it is an interesting extension using this unusually large genetic study.”
As with all research, there are some caveats to consider. The genetic scores used in this study cannot predict an individual person’s personality or future behavior. These genetic associations operate as probabilities across large groups of people, not as deterministic rules for any single individual.
“General readers often think of genetic influences as implying that something is set in stone, and that is certainly not the right takeaway from this, as well as other, genetic studies,” Wertz told PsyPost. “The genetic influences identified here, as well as in previous studies of personality, are far from 100%, leaving much room for non-genetic influences. In addition, even the genetic influences that have been observed likely interact with a person’s environment in shaping their personality.”
Indeed, the 4.8 to 9.3 percent heritability found here, a measure of how much of the differences in a trait between people can be explained by their genes, only accounts for common genetic variants. Previous research using different methods, such as studies involving identical twins, estimates that genetics overall account for roughly 40 to 60 percent of personality differences. This suggests that rare genetic variants and complex interactions between genes likely account for the remaining biological influence.
In the end, while the researchers found that genetic associations for personality are relatively unconfounded by the family environment, a person’s surroundings still play a massive role in their development. Going forward, Wertz is eager to see how these new genetic tools might help untangle that process. She specifically pointed to the potential of polygenic scores, which are single numbers that estimate how likely a person is to have a trait based on thousands of their genetic variants. “I’m excited to see the polygenic scores used from this GWAS in follow-on research, such as in research on how personality traits develop from childhood to adulthood, or in studies that examine why people’s personality traits are so strongly linked with important life outcomes, such as health and employment outcomes,” she said.
The study, “Robust inference and correlates from genetic associations with personality,” was authored by Ted Schwaba, Margaret L. Clapp Sullivan, Wonuola A. Akingbuwa, Kerli Ilves, Peter T. Tanksley, Camille M. Williams, Yavor Dragostinov, Travis T. Mallard, Justin D. Tubbs, Wangjingyi Liao, Lindsay S. Ackerman, Josephine C. M. Fealy, Gibran Hemani, Javier de la Fuente, George Davey Smith, Priya Gupta, Murray B. Stein, Joel Gelernter, Daniel F. Levey, Urmo Võsa, Liisi Ausmees, Anu Realo, the Estonian Biobank Research Team, Mariliis Vaht, Jüri Allik, Tõnu Esko, René Mõttus, Uku Vainik, Gudrun A. Jonsdottir, Gudmar Thorleifsson, Árni Freyr Gunnarsson, Gyda Bjornsdottir, Thorgeir E. Thorgeirsson, Hreinn Stefansson, Kari Stefansson, Rosa Cheesman, Qi Qin, Elizabeth C. Corfield, Helga Ask, Fartein Ask Torvik, Eivind Ystrom, Martin Tesli, Dorret I. Boomsma, Eco J. C. de Geus, Jouke-Jan Hottenga, Dener Cardoso Melo, Harold Snieder, Catharina A. Hartman, Charley Xia, Archie Campbell, Michelle Luciano, Ian J. Deary, W. David Hill, Seon-Kyeong Jang, Scott I. Vrieze, Gonçalo Abecasis, Michelle K. Lupton, Brittany L. Mitchell, Petra V. Viher, Lucía Colodro-Conde, Nicholas G. Martin, Sarah E. Medland, Eske M. Derks, Briar Wormington, Jaakko Kaprio, Karri Silventoinen, Teemu Palviainen, Agnieszka Musial, Kaili Rimfeld, Robert Plomin, Margherita Malanchini, Danielle M. Dick, Fazil Aliev, the COGA Collaborators, The Spit for Science Working Group, Laura W. Wesseldijk, Fredrik Ullén, Miriam A. Mosing, Henry R. Kranzler, Yaira Nunez, Sarah Beck, Renato Polimanti, Tobias Edwards, Alexandros Giannelis, Emily A. Willoughby, James J. Lee, Matt McGue, Antonio Terracciano, Michele Marongiu, Edoardo Fiorillo, Francesco Cucca, Angelina R. Sutin, Peter J. van der Most, Albertine J. Oldehinkel, Tina Kretschmer, Andrey A. Shabalin, Anna R. Docherty, Robert F. Krueger, Colin D. Freilich, Binisha H. Mishra, Terho Lehtimäki, Olli T. Raitakari, Mika Kähönen, Aino Saarinen, Henrik Dobewall, Liisa Keltikangas-Järvinen, Klaus Berger, Marisol Herrera-Rivero, Fabian Streit, Swapnil Awasthi, Stephanie H. Witt, Johanna Tuhkanen, Katri Räikkönen, Johan G. Eriksson, Jari Lahti, Gail Davies, Paul Redmond, Adele Taylor, Janie Corley, Tom C. Russ, Marina Ciullo, Teresa Nutile, Jun Ding, Yong Qian, Toshiko Tanaka, Luigi Ferrucci, Lea Zillich, Lea Sirignano, K. Paige Harden, Erhan Genç, Patrick D. Gajewski, Stephan Getzmann, Christoph Fraenz, Javier E. Schneider Peñate, Stefanie Lis, Alisha S. M. Hall, Christian Schmahl, Sabine C. Herpertz, Abdel Abdellaoui, Michel G. Nivard, and Elliot M. Tucker-Drob.
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