Personality is often thought of as something shaped over time by experiences, relationships and the environments people grow up in. 

However, experiences may only tell part of the story, as genetics also appear to contribute to the traits that shape how people think, feel and behave. 

A new international study identified more than 1,200 common genetic variants associated with the Big Five personality traits, raising new questions about how the same genetic patterns may also shape health, behavior and other parts of everyday life.

The Big Five are five broad traits psychologists commonly use to describe personality. 

Researchers combined data from 46 study groups involving more than 1 million people who provided DNA samples and completed personality questionnaires.

The team then compared differences in participants’ DNA with their personality scores to identify genetic variants that appeared consistently across the five traits. 

Researchers identified more than 1,260 common genetic variants associated with at least one of the Big Five traits, more than 800 of which had not been identified before. 

The combined variants accounted for about 5% to 10% of the personality differences observed between people. 

The findings suggest that personality is influenced by many small genetic factors working together rather than by any single “personality gene.” 

The genetic links also appeared across very different groups of people, suggesting the findings were not limited to one age group or population. 

Researchers found that variants associated with a trait such as extraversion could help predict that same trait in people from different countries and stages of life.

Comparisons between relatives, including twins and parents and their children, also showed that the associations could not be explained solely by growing up in the same environment. Even so, the researchers emphasized that genetics account for only part of personality, with life experiences and surroundings continuing to play a major role.

The same genetic patterns were also connected to areas of life beyond personality. 

Variants associated with conscientiousness, for example, were linked to less substance use, greater participation in sports and healthier aging, while variants tied to openness to experience were associated with greater activity at night. Genetic patterns connected to neuroticism also overlapped with several psychiatric conditions. 

Additional links involving education, career outcomes, income and longevity suggested that some of the genetics related to personality may also influence broader patterns in health and behavior. 

Still, the findings do not mean DNA alone can predict personality. 

The identified variants explained only a small portion of personality differences, and some associations varied across age groups, locations and the way personality was measured. 

Instead, the study gives researchers a much larger genetic map for exploring how personality develops and how it connects to health and behavior. 

The findings reinforce that many small influences shape personality, with genetics as only one part of a much larger picture.