What do the world's most successful individuals possess that allows them to be so influential? What is it that gives a rock star, politician, or athlete the courage to perform in front of thousands, even millions, of people, or a business the ability to keep churning out product after product that is game-changing, but also high risk for his company? For these people to do what they do, they need a strong belief in themselves that allows them to persist in the face of failure and to keep trying, no matter their level of . They have an internal drive that tells them they can succeed, that they have the ability to handle whatever comes their way. Is this characteristic unique to them? Or is it something we all can possess?

I wrote my first blog post on the importance of having a strong social support network, and I shared some research on the subject that made it clear that friends and family are key contributors to health and success. With this post, I'm going to cover another tool that also leads to health and success, one that is not external, but rather inside of each of us: confidence. Confidence is "a feeling of arising from one's appreciation of one's own abilities or qualities," and it plays an important role in building healthy relationships, achieving success in your professional life, and staying motivated. Fortunately, it can be developed easily with practice and perspective.

For most of my life, the thought of made my stomach turn and twist. My would build and build in the hours leading up to a class presentation, and you could hear the fear in my voice when I spoke; frankly, I just couldn't handle it. I've seen the same fear in many other students, and in some of my colleagues as well. I had a public speaking professor who once told me that the American people were polled about their greatest fears, and the one thing they feared most, even more than death, was speaking in front of an audience.

But Professor Wells also told me that the only way to be rid of this fear was to face it. I took his words to heart, and over the last two years, I've experienced a major shift in my attitude. I now enjoy the thrill associated with public speaking, whether in a private setting with peers or in front of strangers at a conference or . This confidence extends to my research and writing ability, as well as how I feel during even the most basic social interactions. What was the key to this newfound strength? It may sound silly, but I actually started acting like I believed in myself.

Most people are familiar with the term "placebo," but for those of you who aren't, a placebo is a term used most commonly in medicine that refers to a pill or procedure that gives the illusion of treatment, but actually provides no physiological effect. For instance, in a study of a new drug for , one group of participants will be given the treatment, while another group will be given a sugar pill (the placebo) instead. Surprisingly, the participants who receive the sugar pill often show signs of improvement, though the sugar pill itself is not providing the relief. The fact that these people are expecting some sort of effect is enough for them to perceive changes that aren't physically there, and this is called the . It has even been observed in cancer patients who received an empty injection, but who nonetheless had their cancer go into remission, simply because they believed they were being injected with a new miracle drug. It seems that the expectations associated with a treatment can often be as powerful as the treatment itself.

Another related construct is called the self-fulfilling prophecy. The term was coined by sociologist Robert K. Murton to describe a phenomenon that dates back to Ancient Greece. Basically, a prediction about the outcome of a situation can invoke a new behavior that leads to the prediction coming true. For example, if I believed that I was going to fail an exam, that belief may have led me to alter the strategies I used for preparation and taking the test, and I would probably fail it. While I may have had a good chance to pass, my belief hindered my performance, and I made this belief become reality. Psychological research shows that the self-fulfilling prophecy works for both negative and positive predictions, indicating again that the beliefs you hold have an impact on what happens to you.

The point I'm trying to get at here is that you can start to build your confidence right now by telling yourself that you've got it in you; the more you believe that you are capable, the more you will be. The placebo effect tells us that expectations alone can be strong enough to overcome diseases and afflictions, and the self-fulfilling prophecy illustrates how your predictions about a situation influence the outcome, so why shouldn't you be able to alter your expectations about your own abilities and experience a renewal of confidence? Get into the routine of telling yourself that you can be successful in all aspects of your life, and you may find that you are not only able to handle many more challenges, but that you have been able to all along.

Important, too, is your ability to put your performance in perspective. Not every speech you give, point you raise, or question you ask will be perfect, and for some of us, remembering the failures is far easier than remembering the successes. But if you want to build your confidence, you need to call upon the times when you've triumphed. Try to recall just one of these moments for each moment of failure that plagues you, and you'll find yourself much better off. And remember that even when everything else is out of your control, there is one person who should always be on your side: you. If you can depend on yourself, you'll find that other people can, too.