The following overview of body language expressions that support speakers' credibility and the overall success of their speeches has recently been published on the Harvard Business Review website. It's based on research by the Center for Body Language which analyzed the non-verbal communication of world leaders from different fields.
1. The Clinton box
At the beginning of his political career, Bill Clinton used big arm gestures in his speeches, undermining his credibility. Advisors then told him to imagine having his body from his shoulders to his belly in a box so that his arms could only gesture to a certain width.
2. A ball in your hands
Another way for keeping your arms close to your body is to imagine holding a ball in your hands. Arm gestures in this width indicate the speaker's self-confidence and that they have things under control, literally holding things firmly in his hands. Steve Jobs was used these gestures when speaking.
3. Building a pyramid using your fingers
Nervous people don't know what to do with their hands. They often tap their fingers or play with something they have at hand. But if you want to look confident, you have to keep your fingers calm. In business, there is a commonly used "fingers pyramid" gesture which signalizes strength and calm. However, if you use it too often, you can seem arrogant.
4. Taking a wide stance
Weak posture equals weak presentation. Self-conscious speakers therefore take a strong stance keeping their legs as wide as their shoulders. They keep their head and neck upright. This makes them feel and look more self-confident.
5. Palms turned up but also down
Turning palms upward shows openness and a sincere interest in getting closer to the audience. Turning palms down, however, doesn't have to mean anything negative. This can be a gesture of authority and assertiveness (not aggressiveness). Like Barack Obama, for example, you can use this gesture to calm the audience.
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