3 types of thinking you can do without (The Tampa Tribune)

Attitude could play a role in your health and longevity. While you are the master of your own attitude, you also could have a positive effect on other people's attitudes. A Harvard Medical School study found that one person's happiness triggers a chain reaction that benefits not only his friends, but his friends' friends, and his friends' friends' friends. And the effect lasts for up to a year!