Mind Your Manners

Dr. Forni says choosing to act in a civil manner has proven more beneficial than self-satisfaction. "I'm not a physician, but any doctor will say that when we are involved in a rude encounter, there are hormones—like catecholamines, for instance, cortisol—that are cascading into our system and they are making our immune system weaker," he says. "If you have a boss that you perceive to be unfair, you're much more likely to have cardiovascular disease."

The bottom line? Going through life rude and angry can make you sick.