Image credit: Concept illustration by Suzanne Kantra/Techlicious via ChatGPT
Why is one person the life of the party while another would rather stay home with a book? A study published in Nature of 1.14 million people, the largest genetic study of personality to date, finds that thousands of tiny genetic differences help shape how outgoing, anxious, organized, or curious you are.
The researchers compared study participants' genetic data with assessments of their personality across the Big Five traits: extraversion (sociability, assertiveness, and energy), agreeableness (compassion, respectfulness, and trust), conscientiousness (organization, productivity, and responsibility), neuroticism (anxiety, depression, and emotional volatility), and openness to experience (imagination, curiosity, and sensitivity to art and nature).
The team looked for genetic variants and checked whether each version lined up with higher or lower scores on a personality trait. More than a thousand variants turned up, most of them in regions of the genome never before linked to the trait in question.
Researchers combined the tiny effects of a person’s variants into a single polygenic score, their best estimate of that person’s genetic leaning toward a trait such as extraversion. Across large groups, the score predicted personality better than any single gene variant could.
“There isn’t a single gene for being outgoing or conscientious,” said Henry R. Kranzler, MD, a University of Pennsylvania psychiatry professor and study co-author. And for an individual, the genetics offer a limited guide: plenty of participants with a low genetic score still scored high on a personality trait, and vice versa.
As a whole, common variants explained less than 10% of the differences in personality scores. The study points to experience, relationships, and upbringing also playing a substantial role.
Personality keeps changing across a lifetime and can shift with experiences such as therapy, the researchers note, and genes and surroundings can reinforce each other. Genetic profiles tied to openness made people more likely to move into cosmopolitan neighborhoods, and living there could make them even more open.
Most of the data came from people with predominantly European genetic ancestry, and the scores predicted personality less strongly in people with predominantly African genetic ancestry. The researchers call for larger studies spanning more ancestral and cultural backgrounds to learn how widely these patterns apply.
