How Personality Affects Gene Expression And Immune System Function

Health depends on a number of factors -- genetics, environment, lifestyle factors, and according to new research, personality might also play a large role in determining health outcomes.

Some research has suggested that personality can play a role in the risk of developing certain physical health problems. Now, a new study has found that personality traits may also be a factor in how well the body fights disease.

Personality traits including extroversion, neuroticism and conscientiousness -- considered to be part of the "big five" personality traits, which also includes agreeableness and openness -- play an important role in immune system function, according to research recently published in the journal Psychoneuroendocrinology.

In a study of 121 healthy participants (with an average age of 24 years old), researchers from the University of Nottingham examined the relationship between these personality traits and patterns of gene expression. The participants filled out personality evaluations, answered questions about their health behaviors. Then, the researchers analyzed their blood samples to examine the activity of 19 different genes involved in inflammatory immune responses.

While extroversion was associated with greater expression of pro-inflammatory genes, conscientiousness was associated with reduced expression of pro-inflammatory genes. This suggests that extroverts are more able to fight off infections.

Inflammation is a response initiated by the immune system to fight off foreign invaders. While this response is an important way that the body stays healthy, too much inflammation can lead to a number of health problems. The findings suggest that extroverts may be more able to fight off infections, but they might also be more vulnerable to harmful chronic inflammation.

While the association is intriguing, more research is needed to pinpoint the biological mechanisms underlying the link between personality factors and gene expression.

The findings join a growing body of research investigating the link between personality traits and various physical health conditions. Previous research has found that the Big Five trait of openness to experience may actually boost protective immune system function, while personality types more prone to negative affect (also known as "Type D" personalities) are more likely to develop the inflammatory autoimmune condition Ulcerative Colitis. A number of studies have also suggested that those with Type A personalities face a higher risk of heart disease and high blood pressure.