A recent study found extroverted individuals tend to have stronger immune sytems but disputed past theories that tendencies towards depression lead to poor health.
The research team found differences in immune cell genes were actually related to an individual's degree of extroversion and conscientiousness, the University of Nottingham reported.
To make their findings the researchers used highly sensitive microarray technology to look at the relationship between the five major human personality traits and two groups of genes found in human white blood cells: one that plays a role in inflammation and another involved in antiviral responses.
The study included 121 ethnically diverse healthy adults, 86 of which were female and 35 male, with an average age of 24. The participants completed personality tests that assessed levels of "extraversion, neuroticism, openness, agreeableness and conscientiousness." Blood samples were also collected from each individual in order to analyze gene expression.
"Our results indicated that 'extraversion' was significantly associated with an increased expression of pro-inflammatory genes and that 'conscientiousness' was linked to a reduced expression of pro-inflammatory genes. In other words, individuals who we would expect to be exposed to more infections as a result of their socially orientated nature (i.e., extraverts) appear to have immune systems that we would expect can deal effectively with infection," said Professor Kavita Vedhara from The University of Nottingham's School of Medicine.
"While individuals who may be less exposed to infections because of their cautious/conscientious dispositions have immune systems that may respond less well. We can't, however, say which came first. Is this our biology determining our psychology or our psychology determining our biology?" Vedhara asked.
The results were independent of other health behaviors as well various subsets of the body's immune system cells. The team found expression of antiviral and antibody-related genes were not associated with any of the five specific personality dimensions.
The researchers noted the data could help provide insight into associations between personality traits and physical health.
The findings were published in a recent edition of the Psychoneuroendocrinology journal.
