More than 1200 genetic variants linked to personality traits

Over 1200 genetic variants associated with differences in personality have been identified, in the largest study of its kind.

The study combined genetic and questionnaire data from over one million people across 46 studies and 13 countries to identify variants linked to the so-called Big Five personality traits: extraversion, agreeableness, conscientiousness, neuroticism and openness to experience. The research team analysed roughly ten million genetic variants for each trait and identified 1260 associated with personality, 824 of them previously unknown. The genetic findings were used to calculate polygenic indices – single 'scores' bringing together the estimated effects of many genetic variants on their related Big Five trait. Further work then explored how these indices were associated with a range of life outcomes in other groups.

Professor Elliot Tucker-Drob, a co-lead author of the study from the University of Texas, Austin, said: 'I view the 1260 variants as kind of a testament to the fact that we've now got the power to answer all of these other questions that we couldn't answer before.'

The findings, published in Nature, suggest that personality is highly polygenic – it is shaped by thousands of genetic differences, each contributing only a small amount. Together, the variants explain only around five to 13 percent of variation in personality, depending on the measure used. However, these genetic associations remained stable across countries, age groups and different methods of measuring personality. In addition, work comparing more than 51,000 relatives indicated that the associations found between genetic variants and personality traits had little to do with the influence of a shared family environment.

The team also explored how the genetic variants they identified were linked to health, education, behaviour and other life outcomes. For example, their work suggests that genetic influences associated with extraversion are linked to a higher risk of COVID-19 infection, while genetic influences associated with conscientiousness were linked to lower body mass index and lower likelihood of starting smoking. However, the authors stress that these sorts of effects need further research.

'These genetic influences do not determine who we become,' said Professor Michel Nivard from the University of Bristol, a co-lead author of the study. 'Personality develops through the concurrent influences of genetics, family and social environments, life experiences and our own choices,' he added.

The researchers caution against using the findings to assess people for employment, education, insurance or healthcare, while highlighting the value of their work in helping researchers understand how biological and developmental factors connect personality with health and life outcomes. The team plans to study more specific characteristics within the Big Five, such as sociability and assertiveness, and to include more participants from globally diverse populations.