"Nothing gives a fearful man more courage than another's fear" – Umberto Eco

This one is just too true and you can put it into practice next time you are feeling a bit scared. I think it is part of the animal side of us. When people say dogs can smell fear, I reckon it means they are able to sense fear in us and know that is time to take advantage of it. Most people will carry a piece of fear with them all day long, so next time you are in a situation and you feel it rising in you and you're not that amped to have it hindering your performance in a one-on-one situation, recognise your 'opponents' fear and take control.

A point to bear in mind is that this animal like instinct of managing your fear at the expense of another works well while:

• Grocery shopping (there is always much fear in most shoppers that people will actually see all the shit they have in their trolley and even more so that they will be 'bust' with one ply toilet paper)
  
• On the fields of sport (where many athletes know their weakness a whole lot better than you could ever suspect ... this works especially well when confronted with lane rage in the pool. Once you have a person in a head lock and are holding them and their nostrils below water level, the levels of apprehension for one's ability to hold one's breath are pretty infinite)
• Dealing with any confrontation with old people. You will have noticed how little fight most of them have in them. Most often mistook for frailty this is actually a result of so much guilt racked up over the years and not dealt with, that turns to fear.
  

The technique of fear reversal will have no effect on:

• Bank tellers who have the luxury of sitting behind glass as thick as the earths crust and don't care.
• Call center people who are not actually human, but artificial intelligence (designed by the same guys who invented the Rubik's cube) and programmed to see how much grief they can cause in as short a period as possible. At the moment the Vodaphone UK customer care are in the lead (there is a world wide compo to see who can cause the most irritation before we find them out. The prize is a contract to be the exclusive call center for all queries on all subjects world wide).
  

post script: Barking is not necessarily the best way to gain the upper hand her, a good hard look into their eyes will help though. They will feel you have found them out and your courage will build accordingly. Barking is no the best way but it does work.