Study Identifies More Than 1,200 Genetic Variants Linked to Human Personality Traits

Researchers have identified more than 1,200 locations in the human genome associated with personality traits, offering the most detailed analysis yet of the biological foundations of sociability, anxiety, curiosity, and other characteristics. The findings also underscore the powerful role of life experiences and environmental factors in shaping personality. The study was published this week in Nature [study].

“Human personality traits can be grouped into five broad categories known as the Big Five,” said Dr. Ted Schwaba of Michigan State University and his colleagues.

These categories include extraversion, which encompasses sociability, assertiveness, and energy; agreeableness, including compassion, respect, and trust; conscientiousness, characterized by organization, productivity, and responsibility; neuroticism, associated with anxiety, depression, and emotional instability; and openness to experience, which includes imagination, curiosity, and sensitivity to aesthetics.

“Research conducted over the past 100 years has shown that both genetic and environmental factors contribute to differences in personality.”

However, identifying the genetic variants associated with personality is challenging. Many genes may contribute to each trait, and large study populations are needed to detect reliable genetic associations.

For the new study, the researchers analyzed genetic and personality data from 46 cohorts, including up to 1.14 million participants of European and African ancestry.

The researchers identified 1,260 significant genetic associations linked to the five major personality traits. This represents a substantial increase over previous studies, with approximately two-thirds of the associations reported for the first time.

Despite the larger number of discoveries, common genetic variants accounted for only a small proportion of the differences in personality between individuals. They explained approximately 5–9% of the variation in a typical personality measurement, increasing to around 13% after accounting for measurement imprecision.

This estimate is considerably lower than the 40–60% heritability observed in twin and family studies. The researchers suggest that the difference may be due partly to the difficulty of detecting rare genetic variants and measuring complex interactions between genes and the environment.

One of the study’s key findings was that genetic signals associated with personality were remarkably consistent across different regions of the Western world, age groups, and assessment methods. The associations were similar whether people rated their own personalities or were evaluated by someone who knew them well.

The main exception was cooperativeness. Genetic associations for this trait varied more across populations and measurement approaches than those linked to the other personality characteristics.

The researchers also found that genetic profiles related to personality were associated with a broad range of life outcomes, including physical and mental health, substance use, career choices, and the places where people live later in life.

Using a method known as Mendelian randomization, the team found evidence that certain personality traits may causally influence outcomes such as body weight, smoking behavior, and the risk of contracting COVID-19. The analysis also suggested that life circumstances, including educational attainment, can influence personality over time.

Nevertheless, the researchers emphasized that the genetic effects associated with personality are individually very small. They are distributed across thousands of genetic variants and cannot be used to predict the personality or behavior of any one person.

Across the study’s analyses, environmental influences remained a major force shaping personality and individual development.

“Our findings highlight the pervasive influence of personality across many areas of life,” said Dr. Schwaba.

“Personality seems to be relevant everywhere you look.”

“We hope this study will encourage many other scientists to incorporate personality traits into their research fields.”

Dr. Michelle Lupton, a researcher at the QIMR Berghofer Institute for Medical Research, said: “These findings provide new insights into how biology and the environment work together to shape personality.”

“This very large study shows that our genetic makeup plays an important role, with common genetic variation accounting for up to 16% of personality variation in some analyses.”

“The remainder is influenced by environmental factors, including our living conditions and life experiences.”

_____

T. Schwaba et al. Robust inference and correlation between genetic relationships and personality. Nature, published online September 2, 2026. doi: 10.1038/s41586-026-10992-9