An international team of scientists has identified more than 1,200 genetic variants associated with the Big Five personality traits. The findings also suggest that many of the same genetic patterns related to personality are related to a wide range of life outcomes, including health, longevity, education, careers and income.
The study, led by the Revived Genomics of Personality Consortium, pooled data from 46 research cohorts around the world. Participants provided DNA samples and completed questionnaires designed to measure the Big Five personality traits: openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism.
These traits describe relatively stable patterns in how people tend to think, feel, and behave. The researchers compared the participants’ genetic data with differences in their personality scores to identify genetic variants associated with each trait.
No gene determines personality
“There is no single ‘personality gene,'” said Ted Schwaba, lead author of this study and professor in the MSU Department of Psychology. “Personality traits are associated with many genetic variants, but even the largest effects of individual genetic variants remain very small. However, although any individual genetic variant makes very little difference to personality, the effects of many variants together may be more important.”
Although the influence of any one genetic variant was small, the researchers found that their combined effects were more substantial and consistent. Genetic patterns also seemed to hold across very different groups of people.
For example, variants associated with extraversion in a young adult living in the Netherlands could also help predict extraversion in a retired older adult in the United States. Using methods that compared relatives to each other, the team found evidence that these genetic associations could not be explained simply by growing up in the same environment.
Still, genetics are only part of the picture. The findings also reinforced the important role a person’s environment plays in shaping personality.
The genetics of personality reaches daily life
Researchers found that genetic variants associated with personality overlap with genetic patterns connected to many other areas of life. These include physical and mental health, longevity, education, career options and outcomes, as well as how people close to them view people.
Some of the links involved everyday habits. Genetic variants associated with conscientiousness were also linked to being more active during the day. Meanwhile, variants associated with openness to experience and extraversion were related to a greater tendency to be a night owl.
The results also highlight how genetics and environment can interact with each other rather than operating independently.
For example, common genetic variants associated with openness to experience were linked to a greater likelihood that someone would move to a more cosmopolitan neighborhood. Living in that type of environment could reinforce or further shape the same personality trait.
Genetics, environment and life outcomes
“Personality seems to be relevant almost everywhere. We hope that this study will encourage many other scientists to incorporate personality traits into their fields of study,” Schwaba said. “For example, genetic variants associated with neuroticism predict more time spent in the hospital, which is relevant for physicians and health researchers, and variants associated with openness to experience are related to income and job change, which is relevant for vocational researchers.”
The findings suggest that studying the genetics of personality could have implications far beyond psychology, and could inform research in medicine, health, education and the workplace.
Funding was supported in part by grants from the National Institute of Mental Health and the National Institute on Aging.