They bully other kids because they feel the bad things they do are justified.
They are more insecure inside and more frightened than the kid they bully.
And probably the main reason is how their parents are treating them.
Probably the father is beating the mother or the kid. Or the mother isn't home when she needs to be. I think you get the idea.
I have been bullied countless times. But I've never been frightened. I understand how they feel. After the bulling is over I usually talk with them why they do it and that I understand why they do it. It helps not always.
I've always been interested in science and never got good at playing football. This made me look uncool in front of my "friends". When they were joking about that I was telling them that it is a personal choice.
I'm ethereally grateful to my parents that had raised me good so I can deal with every situation. And they never hit me, ever. They sat and talked with me about my problems. I didn't got tons of toys or a car when I was 18. I'm now 21. And really when I look back at the cool kids and the bullies I realize that they haven't progressed much since my last encounter with them. Sadly. Sure I'm wrong about some things I have a lot of things to learn but the problem of the teenagers today is that they have everything (materialistic things) and they don't have the love and attention. They cut themselves, become emo and other things because they want attention. Being raised in a communist country maybe it will seem like hell as it is portrayed in the west but here we had the values just about right. I had respect for my mother, father and the elder people. And in school the discipline was harsh, yes but I think that was the correct thing. Today some things change to the worse.
We rarely had suicides or other unpleasant stuff.

Sorry for the grammar.

[edit on 10/5/10 by defiler]

The article link was definitely an eye-opener for parents like me. I'm thankful that you have laid out these issues here to let us be aware of the problems that our teens often face and making us understand why they act the way they do and know how help may be given.
The major battles happen when you try to change rules that have been in place for years, which is why I advise parents to start as early as possible. A 16-year-old may well say, “I hate you, you’re totally ruining my life.” But your job as a parent is to keep your child safe, that’s number one. Your child’s anger is something you have to be willing to accept.
I find this very true. I'm sure our kids will thank us when they become adults and have their own lives to live. It's truly easy to fall prey to our kid's constant complaints and anger when we put in certain rules that they have to follow, but after reading the possible reasons why teens nowadays are often troubled, i think it's but reasonable enough to protect them from the bad influences outside our home.