Chances are, you have seen the low-confidence death spiral up close at some point in your life. You go to a meeting and someone gets up to give a presentation. He clearly doesn’t have command of the material, so he talks softly into his collar using a shaky voice. Someone asks him to speak up and he loses his composure. While people may feel bad for the speaker, compassion won’t change the fact that any chance he had to convey his point is lost.

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On the flipside, there is a virtuous cycle of confidence as well. A great speaker brings an audience along for the ride. She stands straight, speaks loudly and dares the listeners to come with her. Her command of the material is evident from the start.In a very real way, confidence can be a self-fulfilling prophecy. If you believe that you will succeed, you project that belief in success.

The reason that your own level of confidence matters is that people often need help making judgments about quality. The psychologist Dan Ariely performed an interesting experiment. He had people contemplate the value of him reading his own poetry. For some people, he first asked them how much they would be willing to pay to hear him read his poetry. Others were asked how much they would need to be paid to hear him read his poetry. Later, people felt that Ariely’s poetry was more desirable if they were asked how much they would be willing to pay than if they were asked how much they would need to be paid. (In many ways, this is like the story of Tom Sawyer charging people to paint his fence.)

Recently, Jennifer Tress published a book called “You’re Not Pretty Enough,” which suggests that people need to come to accept who they are and what they look like. It is true that we judge people in part by how attractive they are to us. But the virtuous cycle of confidence plays a role here as well.

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Attractiveness is not measured completely objectively. We judge people’s physical attractiveness by many factors including their actual body type and facial structure, the way they carry themselves, the way they dress, the social energy they project and the way they engage with us. Most of these factors are completely under your control. Anyone can project her beauty to others.

It all starts with confidence.

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If you are not a person who is naturally confident about your appearance, abilities or worth, what can you do?

The first step to finding that inner confidence is to be willing to confront those aspects of yourself that you are least confident about. Any self-doubt that you have comes from some source. Until you admit what it is that bothers you, you cannot begin to make changes to develop more confidence. Then you can face the source head-on. Look around. YouBeauty is full of advice that can help you to address aspects of your appearance that make you feel insecure, whether it’s how to dress for your body, what haircut is best for your face shape, how to treat bothersome skin issues, or myriad other concerns. Even small tweaks can make you feel better about the way you look and give you an overall self-esteem boost.

Second, surround yourself with people who will remind you how special you are. If you have an inner voice that speaks self-doubt to you, ask yourself if you’re spending time with people who echo that negative voice. To counteract your own doubts, spend more time with the people who are willing to argue with your inner voice and to tell you about your strengths. It is easier to present yourself with confidence when you know that there is a friendly face not far away.

QUIZ: Could Your Self-Esteem Use Some Work?

Finally, on those days when your confidence feels lowest, remember that you help to create your own environment. If you walk with confidence that you don’t feel, if you speak clearly when you want to whisper, if you look life in the eye when you want to look away, then the world will respond to your actions.