Woman smiling

If you serve up a smile to people, they usually bounce it back. Hit them with a snarl and watch them scowl instead. Research shows that facial expressions and the moods that accompany them are contagious, probably because they evolved as a means of nonverbal communication between people. You can use the infectious effects of a grin to jump-start an optimistic outlook in yourself by sending others what you want them to lob back at you. A kind word to the man behind the deli counter can get your day bouncing in the right direction.
Smiley face

There's another reason for putting on a happy face: It influences your brain in a positive way. In one study, subjects who were asked to hold a pen in their mouth (causing them to inadvertently make the facial muscle movements characteristic of a smile) rated cartoons to be funnier than did other subjects, even though they were unaware that it was the smile that was boosting their reaction. There's an interesting biological reason for this effect: When you feel down, your brain tells your face you're sad and your facial muscles respond by putting on a depressed expression—and convey back to the brain that, yes, you're feeling blue. Consciously changing the facial muscles so they don't correspond to what you're feeling is a way of sending a different message: "Hey, it's not so bad down here after all." The brain will respond by beginning to change your mood accordingly.
Woman at a desk

Research shows that it's not what happens that determines your mood but how you explain what happens that counts. If an optimist encounters a computer program she can't figure out, she's likely to say, "Either the manual is unclear or this program is hard or maybe I'm having an off day." The optimist keeps the failure outside herself ("the manual"), specific ("this program"), and temporary ("an off day"), while the pessimist would make it internal, global, and permanent. When success occurs optimists say, "Of course dinner turned out; I'm a good cook," while pessimists say, "Boy, was I lucky today," literally snatching defeat from the jaws of victory. If you start to speak to yourself in a more positive way when you succeed and fail, you'll gradually become more optimistic.
Three houses stacked next to one another

It's easy to be envious: Compare yourself to those with thinner thighs and fatter bank accounts and you'll always come up wanting—and pessimistic. But the corollary is also true: No matter how bad things get, there's always someone who's worse off. In one simple study, subjects were randomly divided into two subgroups. One group was to finish the sentence "I wish I were a ______." The other was asked to complete the sentence "I'm glad I'm not a ______." When individuals rated their sense of satisfaction with their lives before and after this task, those who completed the "I'm glad I'm not a ______" sentence were significantly more satisfied than before.
Woman shooting film

Pessimists can't stop depressing facts or negative thoughts from poking into their consciousness, but they can choose not to dwell on them. If you look through a camera lens, you'll find that when one part of the picture is in focus, the other areas blur a bit. (This is a distortion, sure, but sometimes we need to sustain the idea of being in a protective bubble to feel optimistic.) This active self-direction of your own moment-to-moment perspective allows you to create a new life story, one in which you take charge of your emotions and actions. Since research shows that those who feel they have a better sense of control tend to be the most optimistic, why not take charge of where your psychological lens is focused?

Keep Reading: Why optimism is the scientifically proven way to get happier