^^ Although I agree that some bullies have attention problems or come from a family with a not so harmonious family set ups, it is not always the case. Minsan, mas malalim pa ang dahilan at kaaawaan mo rin ang bully.
I understand both sides of the fence, the bully and the the being bullied because I've been there.
The being bullied was experienced by my daughter and the being the bully, we experienced it with our adopted brother. I'll just tell the story of the latter, the bully.
My mom hadn't experienced any social related incidents with us, her own children. But with our adopted, it was a different case. Sya ang pinaka-bunso namin.
It started during preschool years. May susugod sa bahay namin, nagagalit na nanay, bakit daw itinulak ang anak nya at yan tuloy punung-puno ng ice cream ang mukha at damit. Bakit di daw kami marunong magdisiplina, at kung ano ano pa. My mom knows how to discipline children, if not, hindi kami lalaking matitino at nakatapos ng pag-aaral. Kaya masakit sa kanya ng mapagsabihan ng ganuon. Being a peace loving person, hindi sya nakipag-away, said sorry for what our brother did and promised that she'd be stricter with him.
May ibang magulang naman na yung bata mismo ang pagagalitan dahil nagkabukol ang anak nilang lalaki. If we would ask our brother, sasabihin nya na nagaway silang dalawa. Meron din syang bukol dahil sa away. Pero sya lang ang sinisisi. Dinala pa ito sa Barangay ng nanay. 5 years old lang pareho ang bata.
Nangaaway sya dahil tinutukso syang negro, ampon, walang kamukha sa amin. Hindi pa nya nuon naiintindihan ang concept ng ampon pero nasasaktan sya na tinutukso syang kakaiba sa amin at pangit. Kung tinutukso daw ang kapatid ko, hindi naman dapat daw manakit at makipagaway, sabi ng nanay. Ang punto dito, kailangan bang makarating pa sa Barangay ang kaso ng dalawang 5 taon na bata?
So you see, the bully here, my brother, is also bullied upon. Kung marunong lang magtimpi ang mga magulang and not fight the battles of their own children, sana maiintindihan nila where our brother was coming from, and understand too that their child had their own share of faults, too.
Then come elementary school days, nirereklamo naman sya na malikot, di maka-focus sa lessons, nagdi-disrupt ng klase. By this time, pinatingin na namin sya sa Dev Ped. It turned out, our brother is a special child. He has learning disability. His cognitive level is 5 years below the norm. Hindi sya halata, sabi ng Dev Ped, especially during the preschool years since lessons during these years are still easier to learn. Nakita na lang nuong nag elementary siya, when he couldn't catch with the lessons anymore.
Thus, we understood the reason behind sa biglang reaction nya kapag tinutukso, of being physical when he felt he was wronged or when he misunderstood people. Hindi pala nya minsan naiintindihan na yung reaction nya ay nakakasakit.
Now, he's 21 and the therapies helped him. He's now 1st year in college taking up culinary arts. Tapos na yung bully days nya kasi naturuan na sya how to handle his emotions. Di namin akalain na makaka-college pa sya

What I'm trying to say here is that the parents of the aggrieved child should be understanding enough and take actions that will help not just their own child but the other child, too. Kung paguusapan ang problema, pwedeng makita ng mismong anak nila how to handle grievances in a positive way at yung isang bata naman, malaman nya ang mali nya at makita rin ng magulang nya kung saan ang problema ng kanilang anak.
However, if you see that the parents of the bully don't have an open mind (at ipilit na wala silang mali), wala na tayong magagawa duon. Ang mahalaga, as the offended party, we try to settle things in civil manner and if they take it instead against you, kailangan na turuan din ang mga anak natin na lumayo sa mga bully na ito and other ways how to defend himself in a bullying situation.