An international study involving QIMR Berghofer researchers has identified more than 1,200 genetic variants associated with personality traits, revealing that the genetics underpinning
our personalities may also influence many of life's major outcomes.
Published in Nature, the study is the largest genetic investigation of personality ever conducted, combining data from 46 research cohorts around the world. Researchers examined the "Big Five" personality traits: openness to experience, conscientiousness, extraversion, agreeableness and neuroticism.
The findings show that genetic variants linked to personality are also associated with a broad range of outcomes, including mental and physical health, educational attainment, career trajectories,
longevity and social relationships.
By examining how personality and genetics interact with other health traits, researchers can better understand the underlying causes of disorders and identify the most appropriate treatments and interventions for individuals. Importantly, the study found no evidence for a single "personality gene". Instead, personality differences arise from the combined influence of many genetic variants, each contributing only a very small effect.
Lead author Dr Ted Schwaba from Michigan State University said the findings highlight the widespread influence of personality across many areas of life.
"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."
QIMR Berghofer researchers contributed family-based genetic analyses that helped separate the influence of genetics from the influence of shared family environments. By comparing relatives within families, the team was able to show that many of the observed genetic associations could not be explained simply by growing up in the same household.
Associate Professor Michelle Lupton from the Neurogenetics and Dementia Research Group at QIMR Berghofer said the findings provide a new understanding of how biology and environment work together to shape personality. “This very large scale study shows us that our genetic makeup plays a key role, up to 16% of the variation in personality can be explained by common genetic variation. The remaining is due to our environment, which includes our life circumstances and experiences,” she said.
The study also revealed links between personality-related genetic variants and a range of behaviours and lifestyle factors. For example, genetic variants associated with conscientiousness were
linked to higher daytime activity levels, while variants associated with openness and extraversion were linked to night-owl tendencies.
Researchers say the findings highlight the complex two-way relationship between genetics and environment. The study found that genetic variants associated with openness to experience were linked to living in more cosmopolitan neighbourhoods, environments that may then further reinforce those personality characteristics.
Associate Professor Lupton said understanding the genetic foundations of personality could help researchers better understand a range of health and behavioural outcomes.
Personality influences many aspects of everyday life, including health behaviours, social relationships and wellbeing. These findings provide an important foundation for future research exploring how personality may be connected to health and disease across the lifespan."
The researchers hope the work will encourage greater consideration of personality traits in fields ranging from mental health and medicine to education and workforce research.