Imagine there is a glass of water on a table in front of you. It has water in it but it is not full. How do you describe the glass? Do you say “it is half full” or “half empty”? If you describe it as “half full”, you might be an optimist, a person hopeful about the future. If you say “it is half empty”, you might be the opposite—a pessimist.

A new study suggests that your level of feelings of hope may affect your health. People who are hopeful about the future may live longer than those who are always thinking bad things are going to happen. Researchers at Harvard University’s School of Public Health in Boston did the study. They compared women with “a general expectation(预期) that good things will happen” to women who were less hopeful. They found that the optimists had a much lower risk of getting several deadly diseases, including cancer and heart disease.

Kaitlin Hagan, a study leader says optimists tend to(倾向于) take better care of themselves by exercising, eating healthy foods and getting enough sleep. She also says earlier studies show that an optimist can use simple, low-cost methods to increase levels of feelings of hope. She says each night the optimist plans to do two or three simple, enjoyable activities the next day. These activities might include watching the sunrise, visiting a friend, dancing to a favorite song or reading a story with the child.