This is a fantastic video from Brooks Gibbs that explains Bullying in a simple way that school children can understand. Bullying is a power struggle, a game where if you get upset you've immediately lost the game.
He gives some great examples of how to deflect and defuse bullying behaviour through resilience, confidence and self esteem.
Children need to be taught how to solve their own social problems. Stepping in disempowers a child and makes them feel helpless. Give a child the skills to face bullying with positivity and stop bullying now!