DIANE SAWYER REPORTS ON WHAT HAPPENS WHEN TEENAGE GIRLS, CRUEL INTENTIONS, AND NEW TECHNOLOGY CONVERGE, ON ABC NEWS� �PRIMETIME,� THURSDAY, SEPTEMBER14

Everyone knows that adolescence is tough, but with the advance of technology, teenagers today � especially girls -- are redefining what�s fair in love and war on the social battlefield. Diane Sawyer reports on how cell phones, digital cameras and personal websites combine in new ways that seems to encourage and amplify the meanness of teenage behavior. From invading privacy and spreading gossip to humiliating one another, some teens have reached new heights of ruthlessness. This week �Primetime� reports on what one teen describes as a �kill or be killed� virtual playground, THURSDAY, SEPTEMBER 14 (10:00-11:00 p.m., ET), on the ABC Television Network.

So what makes good kids turn so brutal? In an experiment with Brigham Young University child development researchers, �Primetime� brought nearly a dozen teenage girls together and equipped them with computers, webcams, cell phones and more. The girls, who were role-playing, created made-up personalities to show what can happen when vying for the attention of popular kids. Sawyer reports just how quickly the girls worked � using sexual innuendos and verbal attacks -- to reach the top of the social hierarchy.

Although boys and girls both participate in Internet hazing � both in the �Primetime� experiment and in real life -- experts say that girls are more invested in the potential of �cyberbullying.� �Girls are more sensitive about establishing relationships, and hurting relationships and manipulating,� says Dr. Clyde Robinson of Brigham Young. �They�re going after the emotional jugular.� One girl tells Sawyer, �In middle school, girls would bring their camera phones into the locker rooms, if they didn�t like certain girls. That�s the way they would get back at her.�

�Primetime� also looks at the difficulties parents face in monitoring what their kids are doing on the web. As Dr. Elizabeth Englander of the Massachusetts Aggression Reduction Center says, �Kids are natives to the Internet and adults are the immigrants.� But as the program shows, situations can arise where kids can be naive to outcomes, and severe consequences are the result.

DIANE SAWYER, CHRIS CUOMO, CYNTHIA McFADDEN and JOHN QUI�ONES are the anchors of �Primetime.� DAVID SLOAN is the executive producer.