03/06/2011 03:57 pm ET Updated Nov 17, 2011

My Kid Would Never...

My daughter is just five. Every day she proudly trots out to wait for the yellow school bus with a big Spiderman backpack overwhelming her small frame. She loves all the Marvel superheroes.

I distinctly remember the day she got off the bus and told me there was an older boy who was taunting her, bullying her, telling her: "Girls can't like Spiderman" or "That's a BOY backpack". I think it hurt me more than it hurt her. And I couldn't believe it had started already. In kindergarten. What's it going to be like when she's in high school? I wondered. How do I teach my daughter and my 8-year-old son to stand up for themselves?

As parents, we all like to think, "My kid would never be a bully... My kid would never stand by and watch bullying happen." But one of the most recent authoritative studies on the subject found that one in three middle and high school students reported being bullied at school. So someone's kid is doing it. And someone else's kid is watching.

At Dateline NBC, a team of us started talking about all of this months ago. We wanted to find a way into the world of teenagers -- to see how kids respond when they're confronted with bullying and there are no adults around. As we all know, most bullying happens when there are no parents or teachers or coaches in the room.

We invited groups of girls to what they thought was a fashion shoot. We invited groups of boys to a gymnasium to compete in athletic activities. In every case, their parents knew what we were really up to. We had rigged the fashion room and gym with hidden cameras. In the room were not only "real" kids, but a bully and a victim -- played by actors we hired. The actor bully was instructed to use very realistic words to bully the actor victim. The words were painful to hear.

For hours I sat with groups of parents and watched their children to see how they would respond to what they thought was actual bullying. And here I have to give these parents a lot of credit. Most of them thought their children would "do the right thing." (Their kids would never...) But how could they be sure?

It was an emotionally exhausting exercise. We saw kids who did absolutely nothing. We saw kids who took sides with the bully and joined in. We saw a few -- but only a few -- teens who jumped to the defense of the victim. It was certainly not a scientific experiment but it was fascinating. The parents were at times saddened or frustrated and at times proud. And when we told the teenagers what had really been going on they were surprised but relieved that what they'd been witnessing wasn't real. Everyone learned something.

I learned to tell my kids that being a bystander and doing nothing is not a neutral position. By doing nothing, the teens let the bad behavior continue. They were the audience. And bullies thrive on attention from an audience.

I learned to understand that it is very difficult to stand up to a bully. These were good kids. Their parents have talked with them about bullying, tried to teach them. In many cases the teens told us afterward that they knew what was happening was wrong. And still they felt paralyzed, unable to say anything to confront the bullying. I learned that kids need very specific language they can use. It's not enough to teach them to "be nice". I need to teach my kids to identify what they don't like and what they want changed. For example -- "I don't like the way you're treating her and I want you to stop." And it takes practice to be able to say that out loud.

I learned that adults set the tone. We sent a coach into the boy's gym to instruct them. When we asked him to act like he was condoning the bullying (he told the victim/actor to "man up"), the bystanders were even less inclined to speak up. But when the coach said he would not tolerate abusive behavior the kids felt emboldened to stand up to the bully after the coach left the room. We set the tone.

I also learned that there is power in numbers. Again and again, when one child spoke up against the bullying or took action others would follow suit. It doesn't take much either. A simple reassuring hand on the victim's shoulder can change the whole dynamic in a room. It shows the bullies that you're not going to let this person be victimized.

Most of all I learned that I need to talk with my kids right now. It's really never too early to start instilling lessons about human dignity and respect for all people. The experts all advise parents not to wait for bullying to come up in conversation. Start talking now.

My daughter and I have already had several conversations. I've told her if that boy turns up again she could say -- "There's no such thing as a girl backpack or a boy backpack."

Maybe she won't find her voice right away. But we have to start somewhere.

"My Kid Would Never... Bully" airs Sunday at 7pm ET/6pm CT on Dateline NBC