SC Connecticut News

Researchers at Yale School of Medicine (YSM) have identified new genetic sites associated with specific personality traits, advancing the understanding of how DNA influences personality. The findings were published in Nature Human Behavior on August 12.

Using data from the Million Veteran Program, researchers conducted a genome-wide association study (GWAS) to identify genetic variations, known as "loci," linked to the "Big Five" personality traits: extraversion, openness, agreeableness, neuroticism, and conscientiousness. This study combined data from previous GWAS to perform a meta-analysis involving nearly 700,000 individuals, making it the largest GWAS for personality traits to date.

“We are a step closer in that process of increasing the sample size to be able to more clearly understand which variants are truly related to these personality traits,” said Daniel Levey, PhD, assistant professor of psychiatry at YSM and principal investigator of the study.

The Big Five personality traits are scientifically based measures studied using self-reported assessments. Participants in the Million Veteran Program completed these assessments and provided blood samples for genetic analysis.

Levey's team found 62 new loci associated with neuroticism and identified loci for agreeableness for the first time. By combining their results with previously published data, they performed a meta-analysis identifying over 200 genetic loci across all five personality traits.

Despite finding numerous genetic variations, Levey hopes future studies will expand participant numbers into millions and increase diversity among participants. Current studies primarily involve people of European ancestry.

“To be able to be confident in saying what direction of effect these variations have and what the actual precise effect of the variation is, we need to have vastly larger sample sizes,” Levey stated. “Current human genetic studies are homogenous relative to world populations.”

The research also investigated genetic correlations between personality traits and mental health conditions. They found strong overlaps between neuroticism and conditions like depression and anxiety. Conversely, high agreeableness was linked with lower incidences of these conditions.

Priya Gupta, PhD, postdoctoral associate in Levey’s lab and first author of the manuscript said that “although genetics are largely beyond our control, gaining a deeper understanding of our personality traits can help us become more aware of potential mental health risks.”

Levey emphasized that while there is a genetic basis for associations between personality traits and certain mental health conditions, these associations do not necessarily last a lifetime.

“Your personality will adapt and change over time," he noted. "Just because we’re finding these genetic variations doesn’t mean that these are things that are fated that you can’t change about your life.”

Levey hopes such studies might inform early treatment for mental health conditions by identifying individuals at higher risk based on their predisposed personality traits.

“When you’re looking at these personality traits that are more predisposed to later developing mental illness...it might be grounds for intervention,” he concluded.