Do you feel confident, secure, and generally good about yourself? Or are you constantly piling on self-criticism, scolding yourself for your many failings, and especially for the way you look? If your answer is the latter, would you like to feel better about yourself, and happier with your own body?

A wholesale change in your attitude about yourself, your feelings of self-worth, and your body image can only happen over a long time, with a lot of sustained effort. But new research by Renee Engeln, Ph.D., psychology professor at Northwestern and author of Beauty Sick: How the Cultural Obsession with Appearance Hurts Girls and Women, has demonstrated that a 10-minute writing exercise, can make a real difference to these feelings in the short term at least.

There are a few different versions of this exercise, but they’re all exceedingly simple. Here is the simplest version, based on the work of Kristin Neff, Ph.D.: Write a letter to yourself, from the perspective of an imaginary friend. This friend is unconditionally loving, accepting, and compassionate. The friend can see all your weaknesses and flaws, as well as your strengths and good qualities. This friend understands human nature in all its glories and imperfections. He or she also understands you, knows your life history, and recognizes how all the experiences you’ve had, good and bad, have helped you become the person you are today. The person that your friend unconditionally loves and values.

What would this friend have to say to you? Set a timer, and spend at least ten minutes writing the letter from this imaginary friend to you. If your friend runs out of things to say before the time is up, try repeating yourself, perhaps using different wording.

Another version of the exercise is designed specifically to help women improve our body image. Nearly all women, whatever our actual appearance, feel ugly, fat, and unattractive at least part of the time. Men can have body image issues as well. So this time, write yourself a letter from your unconditionally loving friend, but have that letter be all about your body. Think about what your friend would say about your body, knowing that he or she loves and accepts it exactly as it is today. What would your unconditionally loving friend say about the parts of your body that you find flawed or unsatisfactory?

“You find imperfection, I find power.”

There are a few other variations of this exercise that Engeln used with various groups of subjects, but I think these letter-writing versions are most powerful. Engeln reports that some of the letters subjects wrote moved her and her research team to tears. “You listen to the images, the media, the voices that tell you that your body is wrong, undesirable, and flawed,” wrote one subject to herself. “But listen to me. Your body is amazing. You find imperfection, but I find power.” She went on, “I see soft shoulders for leaning on and elegant fingers for making music. I see eyes of understanding and a smile that can light up a room.”

Engeln tried different versions of these exercise on more than 1,500 women, some Northwestern undergrads and some sorority members who did the exercises online. In every case, the exercises made them feel better about their bodies, and about themselves in general, whether the exercise was focused on the body or not.

Is it worth spending ten minutes with a pen and paper–or a computer or other device–to give this exercise a try and write yourself a letter, say once every month or every week? I know that when I feel confident and happy about myself, it also makes me more productive and better at my job. So it certainly seems worthwhile to me. How about you?