What is the cruelest form of bullying?

Psychological bullying. It leaves no bruises, no physical wounds, but it hurts, all the same. And you never know when it's coming. It can be done via different ways, and very often it does no good when you seek help. There are no traces, no signs to follow up. The bully will deny everything, and hold up their hands and say, 'Look, it wasn't me. Do you see any blood on my hands?'

When the Bully at Kindergarten is allowed to get away with it he/She will Bully for the rest of its Life