Reasons of bulling

1)I think that the reason of bulling can be that people want to rease their authority.
2)It can be too when people break their rage.
3)I thing that it can be too when people just want to hit or push someone.
4)The fourth reason is when person make someone do something, but another person resists.
5)And the final reason in my oppinion is when person want to revenge.