An international research team has identified 1,260 DNA variants associated with the 'Big Five' personality traits: extraversion, agreeableness, conscientiousness, neuroticism, and openness. The study, which analyzed data from over one million individuals, suggests that up to 16 percent of variations in personality scores can be attributed to genetic factors present before birth.
While each identified genetic variant has a small individual effect on personality, their cumulative impact may be significant. "There is no single 'personality gene,'" stated lead psychologist Ted Schwaba of Michigan State University. "Personality traits are associated with many genetic variants, but even the largest effects of individual genetic variants are still very small."
The research, published in the journal Nature, combined DNA information and personality questionnaires from 46 distinct groups, making it the largest study of its kind. The findings could have implications for predicting an individual's predisposition to certain health issues and life choices.
For instance, genetic variants linked to neuroticism, a tendency toward emotional instability and worry, were associated with increased hospital visits. This connection is considered relevant for physicians and health researchers seeking to understand risks for conditions such as depression, anxiety, anorexia, bipolar disorder, schizophrenia, ADHD, autism, borderline personality disorder, and obsessive-compulsive disorder. The study noted this link was particularly strong for individuals who tend to internalize distress.
Conversely, DNA variants associated with conscientiousness, characterized by organization and self-control, were linked to a lower genetic risk for ADHD and autism. However, these same variants were associated with a higher genetic risk for compulsive conditions like OCD.
While the study did not directly investigate psychopathy, Schwaba indicated that the genetic links to personality could assist the medical field in identifying individuals at higher risk for future mental health challenges. Psychopathic traits are often associated with lower agreeableness and conscientiousness, and in some cases, increased anger and emotional instability linked to neuroticism.
The researchers aimed to understand which common DNA differences are tied to personality and whether these associations hold across diverse populations. They also explored connections between personality-related genes and real-world outcomes such as career success and mental well-being. The large-scale analysis scanned millions of common DNA differences and included comparisons with relatives to distinguish genetic effects from environmental influences. Roughly two-thirds of the identified genetic variants had not been previously linked to the 'Big Five' personality traits. The study estimates that thousands of common DNA differences likely contribute to each of the major personality traits.