Nowadays, one of the most widespread problems in most of schools is violence. In every class there's a person, neglected by the others. No one gives him chance to express himself. And that's the main reason that has an influence on this person's character. There are even some teachers who let themselves bully and sometimes beat such the teenagers.
But the biggest influence on them have other teenagers who do the same. In most of cases on young people' agression a big role have different movies or games. Also the another one reason - is a lack of parental control. If parents will pay attention on their kid, in some time he learns how to behave himself.
There're many schools where there are some children who steal someone else's money and threaten them with a brawl. In my opinion, such aggresive students have a harmful impact on their shy classmates, and they should have a serious talk with their parents, who in their turn must be attentively to their child's upbringing.