Sizes, shapes, colors, clothes, grades, status, personality.
It's a long list of factors that lead to student bullying and even violence, but the other side of the equation is much simpler.
The student who bullies is almost always expressing hidden pain in his or her own life, a national anti-violence leader told more than 100 C.S. Porter middle-schoolers Thursday morning.
"What if," asked Randall Kohn, "everybody stuck up for you? What if we did this every class, every day, every moment?"
Kohn is one of around 40 mentors who work for Rachel's Challenge, a nonprofit school outreach program formed in the wake of the 1999 Columbine High School massacre. It is named for the first victim killed that day, Rachel Scott, and formed by the girl's parents to prevent school violence and bullying.
Kohn was invited by C.S. Porter, which has been aggressively pursuing anti-bullying efforts in recent years. Wherever he is invited to go, Kohn works with a large student population and helps schools form anti-bullying clubs to change "not the weather at the school, but the culture."
On Tuesday, he began by asking the middle-schoolers to stand up and talk about why they wanted to participate in Rachel's Challenge.
But first, Kohn told his own story, one involving an autistic high-school friend who one day climbed to the top of a building and jumped to his death.
"Maybe if I would have reached a little further," said Kohn, holding out his hand, "Kevin would still be here."
C.S. Porter's students told stories of grief and bullying in their own lives, and said they too wanted the culture at their school to change.
"I want to reach out to students because some of them don't have kindness in their hearts," said a seventh-grade girl.
Said another who has long fought with her brother, a senior in high school who will leave home for college next year: "I want that history to be rewritten. I want these next nine months to be the best nine months of our lives."
The 100 students learned how to intervene if they see bullying - giving a "pep talk" to the aggressor, or "running interference" by quickly changing the topic, or even by escorting the bullied student to a safe place.
Everyone is capable of being a bully at some time in their lives, Kohn reminded the students. Bullying is often an expression of personal pain or rejection, so students need to monitor their own behavior and attitudes.
And above all, they need to let the human capacity for empathy guide them, he said.
"I know that everyone in here has light inside them," Kohn said, "and that you have compassion and kindness in your hearts. I know that middle school is a terrifying place to let that out."
On Thursday evening, Kohn also led an anti-bullying seminar at the school with teachers and entire families.
Liz Lombardi, special education teacher at C.S. Porter, said members of Tuesday's crowd of students will continue their anti-bullying work by either forming their own club, or working with the RESPECT Club already in place at the school.
"If even one kid is being bullied," said Lombardi, "it is so consuming in their life that it has to be addressed."
Reporter Jamie Kelly can be reached at 523-5254 or at firstname.lastname@example.org.