How we change what others think, feel, believe and do
When I am aroused I am full engaged and hence more likely to pay attention.
When my emotions are stimulated, my ability to make rational decisions is reduced, making me easier to influence.
Physiology of arousal
Arousal is a physical state which can range from a gentle increase in interest to full-on fight-or-flight reaction, where the whole biology of the body is changed. Think of a time when you were aroused by something. You probably experienced bodily sensations of some kind. There may have been a powerful tingling shooting up your spine. Your might have had a hot flush rushing up you neck and around your face. You toes or fingers may have twitched.
Physical arousal happens when you hear a sudden loud noise or something or someone makes you feel threatened. It also happens when you interest is piqued or an attractive other person flirts with you (or even just walks by).
When needs or goals are affected, either by threat or opportunity, we become emotionally engaged. When emotionally aroused, our rationality reduces, making us more likely to make rash decisions. Hence emotionally aroused people are more open to carefully-placed persuasive methods.
Emotional arousal often happens alongside physical arousal (and it is not always clear which comes first).
Ready for action
When a person is aroused, their whole body is poised for action and they are very easy to tip into doing things, possibly with relatively little thought about the consequences.
Think about the motivating speeches of leaders. Consider the threats of competitors. Remember when you were last in an auction. When you were aroused, you were ready to act at a moment's notice.
If you want somebody to act quickly, wind them up with direct or indirect threats or other immediate things that lead to them to a heightened state of arousal. Beware in doing this that you do not wind them up so much they go in the opposite direction.
To manage your own arousal and those you seek to help, consider building aspects of Emotional Intelligence.
Fisher and Ury (1981) describe interests vs. positions in negotiation.