Hitting other kids is nothing to be "happy" about, your kid is having problems.
You think bullying can give someone superior position in the society, I tell you, this is totally not the case. Do you think a criminal has superior position over you?
Chinese people often have this thought.
But China also has saying: Chi Kui Shi Fu.
To adjust children's behaviors, must examine parents. If somehow, this influence had been given, through owning everything in home, for instance, or observed from parents' behaviors, the child will likely become aggressive.
Consciously, or unconsciously, many chinese parents have planted the aggressiveness in the child.