In my opinion, there are 3 causes of school violence. The first is the family factor. From birth to adulthood, family culture, adult behavior greatly impact their behavior. Parents who are too strict, expect or teach by disciplinary measures will put psychological pressure on them. When the constrained thought is not relieved, the children will bring that inhibition to a burst in another relationship. On the contrary, if parents spoil their children excessively, giving without asking for a gift will also make them feel eager to win, like what they want and easily gather and be drawn by bad behavior.
In addition to families, the school also has a significant impact on the formation of their personalities. Although there are full of organizations such as youth unions, youth unions ... but these organizations in schools are still overlooked, still formal activities. Ethical educational activities such as volunteering, helping friends or playing in the culture, arts, and sports to assert themselves have not had many options. Most schools only focus on learning activities, teaching letters. In addition, with development, the current social environment is really a "matrix" for students. Good information channels are not shared by you, while images and video clips of violence and social evils spread at a dizzying speed. From these things, I think that it is easy for them to be violent towards their friends if we do not have proper teaching methods.