Lower inflammation is associated with less fatigue, a lower risk of depression and a slower decline in reasoning as people age.
People who score higher in conscientiousness or extraversion tend to have lower levels of certain markers of inflammation.
Among the qualities that make up conscientiousness, being hardworking and organised stood out.
For extraversion, which includes both sociability and energy, the clearest result was for people who described themselves as active.
These patterns matter because inflammation that stays elevated over time is linked to both physical and psychological health.
Lower levels of long-term inflammation are linked to a lower risk of heart disease, stroke and premature death.
They have also been associated with less fatigue, a lower risk of depression and a slower decline in reasoning as people age.
Conscientiousness
The researchers pooled data from six studies involving more than 19,000 adults in the United States, England and Japan.
Participants rated how well words such as ‘organised’, ‘hardworking’ and ‘active’ described them.
The researchers then looked at how those answers related to two markers of inflammation in blood samples, C-reactive protein and interleukin-6.
Earlier research had already linked higher conscientiousness with lower levels of both inflammatory markers (Luchetti et al., 2014).
In this study, people who described themselves as organised or hardworking tended to have lower levels of both markers.
Being hardworking showed the strongest association within conscientiousness, even stronger than the association for the overall trait score.
Extraversion
People who scored higher on extraversion tended to have lower C-reactive protein, and much of that association came from how active they said they were.
In fact, being active was more strongly associated with lower C-reactive protein than any other characteristic the researchers examined.
Being talkative showed a small association in the opposite direction, while being lively was associated with lower levels of both inflammatory markers.
In several of the studies, the association with being active held up even after the researchers took other aspects of extraversion into account.
Why energy may matter
Being active and hardworking may both reflect how much energy people have for everyday tasks.
In earlier research, people who scored higher on the activity aspect of extraversion or the achievement-striving aspect of conscientiousness tended to have better aerobic capacity during a brisk walking test (Terracciano et al., 2013).
Regular physical activity could help explain part of the association with inflammation.
The relationship could run in the other direction, too, if people with higher inflammation feel less energetic and come to see themselves as less active or lively.
Related
The study was published in the journal Psychoneuroendocrinology (Stephan et al., 2026).
