What makes you who you are? The sum total of your experiences? The genes you were born with?
It’s a difficult question to contemplate (and one some people struggle their whole lives trying to answer). The answer is more fascinating, but still fraught: The two interact in interesting ways to produce your unique personality. That doesn’t mean, though, you don’t start with a blueprint that can nudge you in certain directions. A study published today in Nature is parsing the genetic variants that make up that blueprint—and our personalities.
Read more: “Does Your Personality Put You at a Higher Risk of Dying?”
An international team of researchers from a variety of disciplines conducted a meta-analysis of 46 cohorts of people from other studies. In each cohort, participants completed a survey designed to measure the big five personality traits—openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism—and gave a DNA sample. The team then sifted through their DNA to identify single nucleotide polymorphisms (one-letter changes to the genetic code) that were associated with the traits.
They found 1,260 genetic variants linked to different personality traits, and according to the team, these variants are also associated with certain life outcomes. Variants linked to extraversion, for example, were associated with a heightened risk for COVID infection during the earliest days of the pandemic, and those with variants linked to agreeableness were less likely to get suspended from school. High conscientiousness variants were associated with increased daytime activity, while variants linked to openness to experience and extraversion were associated with being a night owl.
It’s a remarkable study, but does that mean your life is baked-in from birth, your destiny controlled by a few letter changes in your DNA? Of course not, says the team.
“There is no single ‘personality gene,’” study author Ted Schwaba of Michigan State University explained in a statement. “Personality traits are associated with many genetic variants, but even the largest effects of individual genetic variants are still very small.”
Case in point: One variant linked to more extraversion might make someone score in the 50.35th percentile instead of the 50th, the researchers said. Additionally, personality was found to be moderately heritable, explaining 4.8 to 9.3 percent of the variation in a given personality trait. Collectively, though, these small nudges seem to widen the way toward certain outcomes, and the team hopes future researchers will take note.
“Personality seems to be relevant nearly everywhere you look. We hope this study will encourage many other scientists to incorporate personality traits into their fields of study,” said Schwaba. “For example, genetic variants associated with neuroticism predict more time spent in the hospital, which is relevant to physicians and health researchers, and variants associated with openness to experience are linked to income and switching jobs, which is relevant to vocational researchers.” 
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