If you're the life of the party, you might be more than a good-time Charlie. Turns out, those people who identified themselves as extroverted were typically associated with "pro-inflammatory" genes that help fight infection, according to a recent study conducted by researchers at the University of Nottingham in England and published in the journal Psychoneuroendocrinology.
And, while this study focused on a small segment of a student population, it could increase our understanding about the ways personality shapes physical health.
During the study, researchers recruited 121 students and asked them to fill out personality questionnaires that focused on certain personality traits, including extroversion, conscientiousness and neuroticism. The researchers also collected blood samples and connected those samples to 19 different genes that are active in immune response and defense against viruses.
"Our results indicated that extroverts, those individuals who we would expect to be exposed to more infections as a result of their socially orientated nature, appear to have immune systems that we would expect can deal effectively with infection," says Kavita Vedhara, Ph.D., the lead researcher on the study.
"By contrast, those individuals who may be less exposed to infections because of their cautious or conscientious dispositions have immune systems that may respond less well."
While this finding is interesting, it's important to remember that correlation does not equal causation, says Andrea Bonior, Ph.D., a licensed clinical psychologist in Washington, D.C.
"For instance, perhaps being an extrovert causes these effects because of a person's increased exposure to a variety of germs and boosted immunity," she says. "Or, it might be that your personality is actually affected by your immune system. We just don't know that yet."
It could also be that there is some other variable that's causing this correlation. That's why this study is an important benchmark that can ultimately help us understand the ways in which our personalities influence our health.
"We can't say which came first," Vedhara says. "Is this our biology determining our psychology or our psychology determining our biology?"
More research will help us get answers to these key questions.
"This is very interesting research that should lead to some important new directions within the study of how behavior and personality are connected to physical health," Bonior says.