Thousands Of Gene Variants Contribute To Your Personality, Study Finds

WEDNESDAY, Oct. 28, 2026 (HealthDay News) — Your genes do contribute to the sort of person you are, but it’s complicated, a massive new study finds.

Thousands of common genetic variants contribute to the personality traits that make a person who they are, according to a report based on mounds of genetic data.

Researchers identified 1,260 different genetic variants associated with aspects of personality, according to results published in the journal Nature.

Of those variants, 824 were in regions not previously linked to the personality trait they influence, researchers noted.

These genes in turn are joined by more than 16,000 common variants that could also contribute to each of the “Big Five” personality traits – extraversion, agreeableness, conscientiousness, neuroticism and openness to experience.

So, "there isn’t a single gene for being outgoing or conscientious,” explained researcher Dr. Henry Kranzler, a professor of psychiatry at the University of Pennsylvania.

“What we see instead are thousands of genetic differences that individually contribute a small amount, but collectively shape personality, alongside the many influences of a person’s environment,” he said in a university news release.

For the new study, researchers combined data from 46 research groups, with sample sizes ranging from 611,000 to more than 1.1 million people.

The team found genetic overlap between a person’s personality traits and a broad range of illnesses and habits, including mental health problems, substance abuse and level of physical health.

For example, genes associated with neuroticism were linked to an increased risk of mental health disorders, while conscientiousness was genetically tied to less substance use and more frequent exercise.

The genetic patterns proved surprisingly consistent, with associations similar across age groups, geographic regions, personality tests and self-descriptions versus outside evaluation, researchers said.

However, common genetic variants still explained only 5% to 9% of the differences in personality measured by the study, researchers noted.

Genes predicted behavior only to a small degree, and cannot be used to judge the choices a person will make in the future, researchers warned. Overall, personality reflects both genes and a person’s environment.

"These findings give us a new tool for studying why personality is connected 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.”

More information

Yale School of Medicine has more on genes and personality.

SOURCE: University of Pennsylvania, news release, Oct. 23, 2026