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 connected 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, brought together 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. Researchers compared participants’ genetic data with differences in their personality scores to identify genetic variants associated with each trait.
No Single Gene Determines Personality
“There is no single ‘personality gene,'” said Ted Schwaba, lead author of this study and faculty at MSU’s Department of Psychology. “Personality traits are associated with many genetic variants, but even the largest effects of individual genetic variants are still very small. However, even though any individual genetic variant makes very little difference in personality, the effects of many variants together can be more sizeable.”
Although the influence of any one genetic variant was tiny, the researchers found that their combined effects were more substantial and consistent. The genetic patterns also appeared to hold across very different groups of people.
For instance, variants associated with extraversion in a young adult living in the Netherlands could also help predict extraversion in an older retired adult in the United States. By using methods that compared relatives with one another, the team found evidence that these genetic associations could not simply be explained by growing up in the same environment.
Even so, genetics is only part of the picture. The findings also reinforced the important role that a person’s environment plays in shaping personality.
Personality Genetics Reach Across Daily Life
The researchers found that genetic variants associated with personality overlap with genetic patterns connected to many other areas of life. These include mental and physical health, longevity, education, career choices and outcomes, as well as the way people are viewed by those close to them.
Some of the links involved everyday habits. Genetic variants associated with conscientiousness were also related to being more active during the daytime. Meanwhile, variants associated with openness to experience and extraversion were connected with a greater tendency to be a night owl.
The results also highlight how genetics and environment can interact with one another 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 then reinforce or further shape the same personality trait.
Genetics, Environment and Life Outcomes
“Personality seems to be relevant nearly everywhere you look. We hope this study will encourage many other scientists to incorporate personality traits into their fields of study,” said Schwaba. “For example, genetic variants associated with neuroticism predict more time spent in the hospital, which is relevant to physicians and health researchers, and variants associated with openness to experience are linked to income and switching jobs, which is relevant to vocational researchers.”
The findings suggest that studying the genetics of personality could have implications well beyond psychology, potentially informing 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.
