1) Feeling well helps when you’re not well.
“When researchers look at people who have similar medical conditions, they can predict who’s likely to live longer: the one who feels his health is better. There’s something about that feeling of wellness that’s important, even—maybe especially—if you’re ill. Optimism also seems to help buffer you against stress. I’ve been studying first-year law students for 16 years. That’s a very stressed group, but in my most recent study, each time a student’s optimism increased one point on a five-point scale, his immune response to an injected virus or yeast improved by 20 percent.”

2) Optimism is something you do.
“Anxiety and other negative emotions are known to be detri-mental to the body, especially to your cardiovascular and immune systems, and having an optimistic nature seems to protect against those effects.

In addition, research shows that people who are optimistic about their future behave differently. They exercise more, are less likely to smoke, and follow a better diet. And if they get sick, they’re more apt to actively participate in their treatment. I’ve seen that myself—I have back pain from arthritis, but I think my willingness to do whatever it takes has helped a lot.”

3) Not happy? Don’t worry.
“Happiness is a feeling; optimism is a belief that aspects of your future will turn out well. Happiness can fluctuate a lot, but an optimistic disposition is usually pretty stable. If you’re not optimistic, you can try creating a ‘positive events’ log. Good things happen to everyone, but pessimists often don’t take notice; spending a few minutes every day writing about at least three positive things may help you expect them more often. Or instead of trying to be optimistic, do what optimists do: Work hard to reach your goals. Each accomplishment should make it easier to be hopeful about the next one.”

Depending on which study you read, optimists …

…are 9 percent less likely to develop heart disease.

…are only 77 percent as likely to be rehospitalized after some types of major surgery.

…have blood pressure that’s five points lower, on average.

…live an average of 9.5 years longer.