Optimism and immunity: do positive thoughts always lead to positive effects?

Area of Science:

• Psychology
• Psychoneuroimmunology
• Health Psychology

Background:

• Dispositional optimism, characterized by positive future expectations, has mixed effects on physical health.
• These effects are particularly inconsistent in immunologically mediated diseases like HIV and cancer.

Purpose of the Study:

• To investigate the relationship between dispositional optimism and cellular immunity.
• To explore the mechanisms underlying the mixed immunological correlates of optimism.

Main Methods:

• Analysis of experimental and naturalistic studies examining optimism and cellular immunity.
• Investigation of the role of stressor controllability and personality facets like conscientiousness.

Main Results:

• Optimism shows a negative association with cellular immunity during difficult, uncontrollable stressors.
• Optimism shows a positive association with cellular immunity during easy, controllable stressors.
• Conscientiousness, not negative mood, mediates the effect of optimism on immunity during difficult stressors.

Conclusions:

• The mixed immunological effects of dispositional optimism may stem from differential engagement strategies during varying stressor types.
• This nuanced relationship might explain why optimism does not consistently predict improved disease outcomes.