Psychol­o­gists at Duke Univer­sity have found that enor­mous success is healthy only for people with self-esteem to

For someone strug­gling with a poor self-image, hitting a ball out of the park may tax the immune system,
helping the body to spiral into disease. Instead, the Duke scien­tists
say, the Brians among us stay healthier when success is more modest.

The Duke research is just one example of a new para­digm in
psychoneu­roim­munology, the study of the links among emotion, immu­nity
and the brain. Although we’ve long equated posi­tive emotion with health
and nega­tive emotion with illness, recent studies add nuance and
subtlety to these broad ideas, proving them just partially correct and
in many cases wrong. Among the surprising find­ings: Stress can prime
the immune system, making us stronger.

Read about the study in a Fort Worth Star-Telegram article.