According to this article, entitled "Sniffle-Busting Personalities: Positive mood guards against getting colds", a test study indicated that people with positive moods are less likely to have colds than those with negative moods. Sounds plausible. Their explanation? Positive emotions stimulate symptom-fighting substances. Now call me a half-baked moron, but here's a completely different interpretation for the observed correlations - people with colds are more likely to have negative emotions. In fact, looking back, I think I can say in all honesty that on 100% of the occasions I've had a cold, I felt negative emotions. It's not the correlation that is doubtful in my mind, just the direction of causality. Am I being obtuse here?
This one definitely goes in the dubious research category.