Massive study of over a million people identifies hundreds of genetic variants linked to personality

A groundbreaking genetic study has uncovered numerous DNA variations tied to human personality traits. The findings, published in Nature, reveal that these personality traits, often described by the "Big Five" framework of extraversion, agreeableness, conscientiousness, neuroticism, and openness to experience, are largely consistent across diverse populations and less influenced by family environment.

The research, led by a team from Michigan State University, pooled data from 46 separate cohorts encompassing millions of participants. They identified 1,260 genome locations associated with the Big Five traits, with 824 of these locations previously unknown. Each genetic variant's influence on personality is minute, yet collectively, these common variants account for 4.8% to 9.3% of the population's personality variance.

The genetic signals were consistent across various demographics and measurement methods, including self-reported surveys and assessments from friends. Crucially, the study found minimal genetic similarity between spouses, suggesting that people do not partner based on significant genetic compatibility for personality traits.

Moreover, the researchers discovered that specific genetic variations linked to conscientiousness were associated with lower body mass index and reduced likelihood of smoking. Conversely, traits linked to higher neuroticism correlated with lower chances of healthy aging. However, the study also revealed that life experiences and physical health can influence personality traits; for instance, educational attainment and changes in body mass index may cause shifts in personality.

The study's lead author, Ted Schwaba, emphasized the significance of this comprehensive genome-wide association study, highlighting the intricate interplay between genetics, environment, and life experiences in shaping human personality.