About 7.5 years. That's how much longer researchers found people with positive self-perceptions of aging live after the death of a spouse, compared to their widowed peers with negative feelings about growing old [sources: Martikainen and Valkonen, Levy et al.]. That data is in a study from the 1990s, and scientific evidence continues to suggest those of us who see the glass as half-full report better mental and physical health than those who see the glass as half-empty. Positive thinkers appear to have greater resilience — including fewer cases of the common cold, lower rates of depression and lower levels of distress, in addition to a lower incidence of dying from heart disease [source: Mayo Clinic].
Optimists expect positive outcomes and make statements to others and to themselves (known as self-talk) that focus on "I can" rather than "I can't." Positive thinkers make positive statements — aloud or as part of an internal narrative — such as, "I am conquering my illness," or "I choose happiness." Pessimists, on the other hand, expect the worst. They expect negative outcomes and often experience anxiety, despair and sadness [sources: Zagorski, Scheier et al.].
Optimism and pessimism are what's known as cognitive constructs. We learn and understand the world around us through our personal experiences and interactions, as well as through our reactions to those experiences. There are two types of optimists: the dispositional optimist, for whom optimism is a personality trait (you could say dispositional optimists are born that way); and the situational optimist, who is able to imagine positive outcomes only for some situations. Pessimists fall into similar categories.
Although it remains unclear exactly why optimism is good for us, there's an association between having a positive outlook and having both better coping skills and better cardiovascular health. Heart disease, an umbrella term for multiple cardiovascular diseases (CVDs), is the No. 1 cause of death in the U.S., killing 610,000 Americans each year. That's one in four. Overall, CVDs are responsible for killing more Americans than the total deaths from all cancers combined annually. And the most common type of heart disease, coronary heart disease, is responsible for killing more than 370,000 of those 610,000 [source: CDC].
But when researchers at the University of Illinois studied the effects of optimism on heart health specifically, they found self-reported optimists were between 50 and 76 percent more likely to also score well on seven other metrics. Those are the same metrics outlined in the American Health Association's (AHA) Life's Simple 7 campaign: blood pressure, body mass index (BMI), fasting plasma glucose and serum cholesterol levels, dietary intake, physical activity and tobacco use. And those with most optimistic outlooks were also twice as likely to score in the ideal heart health range [source: Hernandez et al.].