Exercise in Humiliation

Feb. 26, 2008— -- "You're a freak and a nerd! No one likes you, and you have no friends!"

It's the kind of cruelty for which teenage girls are famous. If you're a woman, perhaps you remember just how traumatizing it can be to find yourself the victim of a group of mean girls.

"You're such a LOSER! You smell and you'll never have a boyfriend!"

So, if you were taking a stroll through the park, and you encountered three teenage girls viciously insulting and picking on another girl, what would you do? Is it your job to step in, or should you keep your distance?

CLICK HERE for more reactions caught on tape!

ABC News decided to see how people might react to such a scenario. We hired four teenage actors: three "mean girls" and a victim. Then we went to a busy suburban New Jersey park and, on a park bench over the course of a few days, the girls bullied each other and waited to see how people would react.

The mean girls berated their victim about her looks and social status. They told her she smelled, she was stupid, and she had no friends. These kinds of painful insults and much, much worse, are hurled at kids every day in schools across the country. In a 2005 Department of Justice study, 28 percent of U.S. students, age 12 to 18, said they'd been bullied at school.

We were particularly interested in understanding the difference between the way boys bully and the way girls bully. Two years ago, ABC News tried the same experiment, except that the actors were young boys, and their bullying was mostly physical. When bystanders witnessed the bullying, both men and women stepped in to stop it.

This time, ABC News asked the girls to stick to verbal abuse. We wanted to know if people would be more or less likely to get involved if the weapons were words instead of punches. Do people perceive verbal abuse as "dangerous" as physical abuse?

Studies show that, while girls use more indirect forms of aggression than boys, such as spreading rumors or pressuring peers to reject or exclude a victim, girls' self-esteem and school performance is affected just as much as when the bullying is physical. In fact, verbal and emotional bullying can hurt a teenage girl even more than a physical conflict.