Optimism is a learned skill and there are a variety of ways to acquire it, says psychologist Mary Ann Troiani, co-author of Spontaneous Optimism. Through her research, Troiani has come up with three things that you can do to enhance your sense of optimism. First, straighten out your body before your emotions by keeping a straight body posture, taking big steps and walking quickly with your shoulders back and your head up. "People who are pessimistic walk slowly with small steps and their head down," she says. Second, change your tone of voice so that it is cheerful and full of energy. Third, use upbeat or happier words, such as "challenge" rather than "problem," or think of "opportunities" rather than "losses." "Positive thoughts and behavior have a positive impact on the brain's biochemistry," she says. "[They] boost your serotonin levels and signal that you're happy. Your brain will catch up to you." Troiani reminds us: it takes about 4 to 6 weeks to really change a habit.