Authors conclude that school bullying is not the exclusive province of social outcasts, but is often a tool kids use to try to increase their personal social standing. As such, it's fair to say that the phenomenon is more widespread than might otherwise be thought, and that the interventions called-for in training should take account of the various purposes that motivate the behaviors.
I'm reminded of the baboon behaviors recounted in Robert Sapolsky's wonderful book A Primate's Memoir (stay with me, here), where he reports that physical aggression was used to promote and maintain standing in the social hierarchy. One hopes we can find ways to elevate human institutions above the monkey business of the savannah. Knowing where it comes from is a Start, but not an End point esp. if we homo sapiens want to proclaim our superiority over the rest of the animal kingdom.
The article also contains various tips for parents and for objects of bullying which are critiqued in the Comments. In my own experience, I was bullied/spat-at in a parking lot by a guy who resembled Mr. Clean (he gets bigger with every recollection) he apparently took exception to my bumper sticker politics. Had I accepted his invitation to mayhem, I have little doubt my clock would've become spotless. A digital photo, police report, Assault/Battery charge, defense attorney costs, court-ordered diversion and ample restitution presumably taught him a better lesson than kicking my butt would have.
Fists are pretty dull tools there need to be better institutional alternatives in our schools, not just in our courts. Here's hoping that The Training on the SRVUSD anti-bullying conduct policy is proceeding apace!