Large genetics study finds many DNA links to personality traits

The study brought together genome-wide association studies, or GWAS, from 46 cohorts. A GWAS scans DNA across many people to look for common genetic variants that are more often found alongside a particular trait.

The researchers studied the Big Five personality traits: extraversion, agreeableness, conscientiousness, neuroticism and openness to experience. These are broad descriptions of relatively stable patterns in how people tend to think, feel and behave. They are not diagnoses, and they do not capture every part of a person’s personality.

Depending on the trait, the main analyses included from 611,037 to 1.14 million participants with European-like and African-like genomes. The team also used data from up to 50,725 participants in within-family analyses, which compare relatives. That approach can help researchers test whether a genetic link may be partly explained by the family environment relatives share.

The team identified 1,260 lead genetic variants associated with personality measures. Of those, 824 were described as new findings. The result supports the idea that there is no single “personality gene.” Individual DNA differences had small effects, but many of them together accounted for a measurable share of variation in personality scores.

The researchers estimated that common genetic variants explained 4.8% to 9.3% of the variation in measures of each trait. For personality questionnaires with typical measurement reliability, the estimate was 9.3% to 13.3%. Those figures do not mean a person’s personality is fixed by DNA. They describe patterns across large groups, while personal experiences and environments remain important.

The genetic associations were broadly consistent across geographic settings, age groups, personality questionnaires and ratings made by participants themselves or by people close to them. They were not identical in every setting. That distinction matters: a result that generally repeats across groups is stronger than one seen only once, but it may still vary depending on how personality is measured and who is studied.

The within-family analyses suggested that shared family environments created relatively little distortion in the genetic associations with personality. Still, this does not remove every possible source of bias or prove that genes directly shape every related outcome.

The researchers also examined how personality-related genetic patterns overlapped with behaviors and life outcomes. Their analyses pointed to widespread, potentially causal associations. The word “potentially” is important. Methods such as genetic correlation and Mendelian randomization can strengthen evidence about possible pathways, but they cannot by themselves settle every question about cause and effect.

For example, the news coverage highlighted links between personality-related variants and health, education, work patterns and living environments. These are associations, not forecasts. A DNA result cannot tell an individual where they will live, what job they will have, how long they will live or whether they will develop a health condition.

The study is large and used several complementary methods, which makes it an important contribution to personality research. But the abstract does not provide detailed results for every life outcome or show that findings apply equally to all populations. Further research will need to test the pathways behind these links, examine more diverse groups, and clarify when genetic information adds useful insight beyond social and environmental factors.