Negative states, like jealousy, anger, and hostility, need to be short-lived. It's OK to feel them—that's natural. But you can't let them dictate the next three hours. In the end, being positive is a better deal for you. That emotion, not negativity, will get you where you want to be. So feel annoyed or irritated, but then take a deep breath and let it go. It's not easy, especially when you don't like the person you're jealous of. You have to work up to it. Talk to yourself the way a friend would. She wouldn't say, "Yeah, you're right. You suck." She would say, "You're smart and capable, and things will come together in another way for you."
—Emiliana Simon-Thomas, Ph.D., is the science director of the Greater Good Science Center at the University of California, Berkeley. She lives in Berkeley.