Someone cuts in front of you and steals that parking space. A co-worker shoots down your idea at a meeting. The guy ahead of you in line for coffee chats on his cell phone, oblivious to the person waiting to take his order. Whatever happened to common courtesy?

Before you start to fume, remember that, even though we all get mad at times, it rarely gets us anywhere. Being nice, on the other hand, makes you feel good. It can also improve your health, attract kindness from others, and help you achieve your goals – including your business goals.

When you’re kind, you can expect positive interactions with others, from the stranger on the bus to the client who just accepted your proposal. “People want to interact with those who are nice,” says Ann Marie Sabath, member of the Rotary Club of Cincinnati and president of At Ease, Inc., a business etiquette consulting firm. She is also author of One Minute Manners: Quick Solutions to the Most Awkward Situations You’ll Ever Face at Work. “Whenever you think of something positive about someone,” she recommends, “share it with the person.”

When it comes to business, “Treat your customers like old friends,” says Norman Wright, member of the Rotary Club of Pensacola North, Fla., USA, and president of the Better Business Bureau of northwest Florida. “Be nice to your employees, too, because they’ll in turn treat your customers that way.”

But a good mood can sometimes be hard to come by. Stuck in traffic or in line, you get frustrated, and bad manners get the better of you. You can blame some of this reaction on biology.

Gregory Fricchione, director of the Benson Henry Institute for Mind Body Medicine at Massachusetts General Hospital in Boston, explains how it works: “The brain is outfitted to pursue and protect our basic needs for food, sex, shelter, and control over our lives.” Those can include trying to make it to a meeting on time or asking for a raise. “When your needs are thwarted, there’s a tendency to become irritable and frustrated, which can lead to being unkind.”

But we’re also wired for empathy. “As a species, we’ve evolved to require social support as a survival strategy, and we also have the capacity to provide it,” Fricchione continues. Studies of something called mirror neurons in the human brain have shown that when you see someone in trouble, the neurons in your brain behave in a way similar to those of that person. “This allows you to feel what the other person is feeling,” he says, “and potentially respond with kindness and altruistic behavior.”

When you’re kind to others, you can expect to get a lot of kindness back – even if you’re the only one who knows how nice you are. Try plugging a quarter into a stranger’s parking meter, just for the heck of it. Says Sonja Lyubomirsky, professor of psychology at the University of California, Riverside: “People who commit kind acts feel generous, optimistic, and cooperative, and they look at others more charitably.”

When you’re compassionate, your brain releases endorphins and other neuropeptides. “There may even be a ‘giver’s high,’” says Fricchione. “Your brain’s reward-and-motivation circuitry is stimulated. This not only makes you want to continue to be loving and altruistic, but also it controls the way you respond to stress. Since stress is at the root of many health problems, being kind can potentially make you less vulnerable to diseases.”

Linda Kaplan Thaler, CEO of the Kaplan Thaler Group, a New York advertising agency, built her billion-dollar company “not with fear and intimidation, but smiles and compliments,” she says. In The Power of Nice: How to Conquer the Business World with Kindness, she and the firm’s president, Robin Koval, write: “Every time you smile at a messenger, laugh at a co-worker’s joke, thank an assistant, or treat a stranger with graciousness and respect, you throw off positive energy. That energy makes an impression on the other person that, in turn, is passed along to and imprinted on the myriad others he or she meets. … And ultimately, those favorable impressions find their way back to you.”