Are extroverts healthier?
People who are more extroverted have stronger immune systems than those who tend to be shy, according to a new study.
Scientists at the School of Medicine at the University of Nottingham in the U.K. enrolled 121 adults between the ages of 18 and 59, including 86 females and 35 males, in the study. All the participants were asked to complete a test that measured the five primary dimensions of personality: extroversion, neuroticism, openness, agreeableness and conscientiousness. Then, the researchers took blood samples from the participants, which they used to analyze the activity of white blood cells. Researchers also controlled for various lifestyle factors, including physical activity levels, alcohol intake and whether the participants smoked.
When the researchers compared the results of the personality test with the blood test analysis, they found that the participants who scored the highest for extroversion traits--including being assertive, talkative and enthusiastic--had higher levels of particular pro-inflammatory, or immune-boosting, genes in their white blood cells, when compared with those who scored higher on conscientiousness. A smaller link was found between immune response and traits of openness. No correlation was found between traits of agreeableness and neuroticism and the strength of a person's immune system.
The study's findings, published in the journal Psychoneuroendocrinology, suggest that even though extroverts are typically exposed to more infections as a result of being involved in more social activities, their immune systems appear to be more effective in response to infections. Scientists say they currently have no explanation for why personality traits may be linked to immune system function.