I've often wondered that about dd2 NiceBitOfCheese, she is very rambunctious and outspoken and as I said is prone to violent outbursts if she feels she's been backed into a corner or pushed far enough.
I've spoken to her many times about never hitting out first and how much words can hurt and how lonely it feels to be excluded.
When I've spoken to the teachers about her social life at school they've told me she is "class mother" she is very emotionally mature for her age and has a strong sense of fairness and is always the first to make an effort if she sees someone on their own. They are aware of her temper but tell me it mainly only comes into play when she sees others being bullied or hit, though it has gotten her into trouble at times, she's never been the one who has started it and has never been thought of as a bully. She just needs to learn that threatening to stamp on someone's toes because they called your friend snotty is perhaps not the best way of dealing with conflict.
Dd1 admitted being a bully to me in the past, I made her write a letter of apology to the victim, who now worships her, much to her dismay, although she's never since bullied him, nor is she keen on being his friend or saviour. She will tell the teachers if she sees him being bullied and will reply politely when he talks to her.
I spoke to one of dd1's bullies mothers, who was totally unaware of the situation and was shocked and ashamed and couldn't apologise enough. She had thought that they were still good friends and had no idea they'd fallen out, much less that her child was harassing dd1 both online and at school. Sadly after she spoke to her child she claimed it was all a misunderstanding and that dd1 had exaggerated things. I wanted to forward her some of the bile that her child had been sending mine, but dd1 begged me not to.