Always Look on the Bright Side of Life

Winston Churchill once defined a pessimist as one who sees the difficulty in every opportunity, but an optimist as one who sees the opportunity in every difficulty. New research shows that optimists, who already enjoy better goal attainment, more resilience, and better overall well-being compared to pessimists, also enjoy a healthier immune system. The new study, published in Psychological Science, reports that a positive outlook actually boosts immunity.

The authors examined 124 first-year law students to explore the connection between optimism and cell-mediated immunity. The students completed questionnaires and immune-system checks at 5 points over the course of the year. As the students endured classes, exams and interviews, their optimism rose and fell, along with their immune system function. When optimism increased, so did immunity; when optimism decreased, the immune system weakened.

Optimism has long been related to better subjective well-being throughout life. Optimists fare better during times of stress and adversity than their pessimistic peers, and optimists engage in healthier coping mechanisms and lower levels of avoidance than pessimists. Optimists also achieve success and attain their goals more often than their glass-is-half-empty counterparts. Optimists generally have an energetic, task-oriented approach to life, which promotes academic, economic and social success. Optimists also take pro-active steps to improve their health, versus pessimists who are more likely to engage in destructive health behaviors.

Previous research has connected stress and immune function, and even optimism and immunity, but usually by comparing optimists with pessimists, leaving unanswered the questions of how genetics or individual differences play a role. This new study is among the first to examine optimism and immunity in a single person. While once thought to be a stand-alone system of the human body, the immune system is now known to be highly integrated with the nervous system, responding to changes in the biological, social or psychological environment. Stressors predict a negative immune response.

Since the immune system is a priority for the human body, it requires the optimal functioning of all the integrated and related body systems. If energy is pulled away from the immune system to cope with an outside stressor, less energy is available for the immune system. A negative outlook on life is such a stressor. Cultivating a rosy outlook decreases stressors and allows for the optimal functioning of the body’s systems.

The new research could have implications for mental health treatment. While most therapy now focuses on decreasing negative emotions, increasing positive emotions may be a healthier approach. So, put on those rose-colored glasses and drink from the glass that is half-full. Your immune system will thank you.


Avitsur, R., Powell, N., Padgett, D., & Sheridan, J. (2009). Social Interactions, Stress, and Immunity Immunology and Allergy Clinics of North America, 29 (2), 285-293 DOI: 10.1016/j.iac.2009.02.006

Segerstrom, S. (2007). Stress, Energy, and Immunity: An Ecological View Current Directions in Psychological Science, 16 (6), 326-330 DOI: 10.1111/j.1467-8721.2007.00522.x

Segerstrom, S. (2007). Optimism and resources: Effects on each other and on health over 10 years? Journal of Research in Personality, 41 (4), 772-786 DOI: 10.1016/j.jrp.2006.09.004

Segerstrom, S., & Sephton, S. (2010). Optimistic Expectancies and Cell-Mediated Immunity: The Role of Positive Affect Psychological Science, 21 (3), 448-455 DOI: 10.1177/0956797610362061

Jennifer Gibson, PharmD

Jennifer Gibson, PharmD, is a practicing clinical pharmacist and medical writer/editor with experience in researching and preparing scientific publications, developing public relations materials, creating educational resources and presentations, and editing technical manuscripts. She is the owner of Excalibur Scientific, LLC.
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