When it comes to our health, there are essentially four things under our control: the decision not to smoke, a commitment to exercise, the quality of our diet, and our level of optimism. And optimism is at least as beneficial as the others.

It's a matter of ABC: When we encounter ADVERSITY, we react by thinking about it. Our thoughts rapidly congeal into BELIEFS. These beliefs may become so habitual we don't even realize we have them unless we stop to focus on them. And they don't just sit there idly; they have CONSEQUENCES.

Some find that very optimistic people have benign illusions about themselves. These people may think they have more control, or more skill, than they actually do. Others have found that optimistic people have a good handle on reality. The jury is still out.

Success requires persistence, the ability to not give up in the face of failure. I believe that optimistic explanatory style is the key to persistence.

The pursuit of happiness is enshrined in the Declaration of Independence as a right of all Americans, as well as on the self-improvement shelves of every American bookstore. Yet the scientific evidence makes it seem unlikely that you can change your level of happiness in any sustainable way. It suggests that we each have a fixed range for happiness just as we do for weight. And just as dieters almost always regain the weight they lose, sad people don't become lastingly happy, and happy people don't become lastingly sad.

Habits of pessimism lead to depression, wither achievement, and undermine physical health. The good news is that pessimism can be unlearned, and that with its removal depression, underachievement, and poor health can be alleviated.

When well-being comes from engaging our strengths and virtues, our lives are imbued with authenticity.