It’s so easy to frown, and there are so many things to frown at: a colleague who comes into your office and chats as if you have nothing else to do; a stack of bills; traffic riddled roads. But when we take these frown makers and trade them for a smile, a funny thing happens: Our annoyance starts to slip away. Unless of course, we are hell bent to stay annoyed. The next time you’re tempted to frown at someone, try grinning instead. The person may be taken aback, and you’ll be surprised at how your attitude will follow the expression on your face.

Many women spend tons of money on products to enhance their looks and, in particular, their faces. Anti-wrinkle creams abound with the promises of youth. Mascara, blush and eye shadow are designed to give our faces a lift. However, have you ever considered the fact that the expression on your face has a lot more to do with the types of thoughts you have rather than any magical makeup or lack of wrinkles.

If you were to park your car on a busy street and observe people walking by, you would see an inordinate amount of stern faces, clenched jaws and just plain grumpy looks. These uptight faces, in turn, create uptight bodies, which the brain translates into believing you are getting ready to fight or flee. By the end of the day you will probably resemble a dead parrot.

As children, you had from 18 to 20 facial expressions. By the time you became an adult, you were down to four. Since adulthood is supposed to be more serious and important than childhood, being too expressive may make us afraid of appearing foolish. As grown-ups we restrict foolishness, play and happy faces until its Friday or we’re on vacation. This is not necessarily true for everyone but the cultural norm is that looking serious is much more in alignment with being successful. The ultimate irony is that companies that have made fun part of their mission statements are often highly productive.

Smiles, frowns and grimaces were once seen simply as expressions of feelings. However, researchers now see the face as a body organ of its own. The “facial feedback hypothesis,” first proposed by Charles Darwin, suggests that if you ask a person to smile, that person soon begins to experience the pleasant feelings associated with that expression. The head of plastic surgery at a local hospital told me that as we age, our faces set into a mask. If this is true, it’s important to keep our facial muscles flexible by laughing and perhaps by making funny faces.

A pleasant smile can help you to have a relaxed mental state and body. Why not give it a try? It’s free, and you’re liable to get a wonderful reaction—someone might smile back.

— Author, humorist, PBS star and Fortune 500 trainer Loretta LaRoche lives in Plymouth, Massachusetts. To share your pet peeves, questions or comments, write to The Humor Potential, 50 Court St., Plymouth, MA 02360. Visit her website at stressed.com.