In a downside triumph of gender equity, one can no longer assume that the playground bully is a boy, social scientists are now reporting.

"More and more girls are becoming aggressive in ways traditionally reserved for boys," says Kenneth Goldberg, executive director of the Earlscourt Child and Family Centre in Toronto. "And I mean physical fighting -- real in-your-face aggression."

Of course, some girls have always been aggressive, Mr. Goldberg acknowledges. Historically, girls have been one-quarter as likely as boys to receive treatment for problems like aggression and disobedience. "But now we're finding girls coming in at double the historical rate -- one girl for every two boys," Mr. Goldberg says.

The whole issue of girlhood aggression will be explored in a two-day symposium -- jointly sponsored by the Earlscourt Centre and York University's LaMarsh Centre for Research on Violence and Conflict Resolution -- that begins tomorrow at Mt. Sinai Hospital in Toronto. Experts from across the continent will participate.

There seems to be little agreement on just why girls are turning to violence.

Aggressive boys wish to assert power. But do girls have the same motivation? Mr. Goldberg believes they often don't -- rather, they seek revenge for perceived slights, rejections, or injured feelings.

Sybille Artz, another presenter at the symposium, demurs. "My research would suggest that whenever violence is used, it's about the establishment of power. In fact, the more disempowered a young person feels, the more likely they are to turn to violence."

Girls are quite like boys in seeking status and power, Ms. Artz says. Unfortunately, the only models of status and power held up for view are those that properly belong to boys and men.

"What this means is that girls are always dependent on one form or another of acceptance by males," Ms. Artz says. "To get the attention of males, some will manipulate females to stay on top of what I call the 'pretty power hierarchy.' And if they don't have the physical attributes for that, they attain power by becoming 'one of the boys,' and have to show they're as strong, cool and dominant as the toughest boys are."

Ms. Artz sees disadvantages to such strategies. Too much aggression in pursuit of power can cause the law to step in -- with a consequent loss of all power over one's life. And a surfeit of aggression can lead to abandonment by most of one's peers, leaving only a narrow and unimpressive band of people to associate with.

Ms. Artz, the author of Sex, Power and the Violent School Girl, believes girls most often fight each other over boys. "You interview these girls and always hear the same reasons -- 'she looked at my boyfriend,' 'she talked with my boyfriend,' 'she slept with my boyfriend.' Much of this would not happen if girls weren't so subject to sexual objectification."

Ms. Artz, who is director of the University of Victoria's School of Child and Youth Care, alluded to last spring's murder of 14-year-old Reena Virk in the B.C. capital.

"Her murder shows a pattern in female violence. The girls who beat her up resented her contact with boys they were involved with. But if those girls hadn't been so sexually objectified, they wouldn't have taken such a tragic route to affirming their power. Without condoning what they did, society has to understand this."

Most aggression by girls ends far less tragically than it did in the Virk case. As the Earlscourt Centre's Kenneth Goldberg says, girls still resort to such verbal aggression as teasing, sarcasm, and name-calling more often than boys do, and are more likely to ostracize their victims.

Mr. Goldberg said that contrary to myth, bullies do not necessarily have self-esteem problems. "Why should they?" he asks. "Bullying often works. A child intimidates another child to get the ball on the playground -- and he gets the ball. A lot of bullies in that situation think highly of themselves."

Treatment, he says, is usually more effective if it avoids self-esteem issues and focuses instead on anger management.

One of the most important treatment goals is to prevent aggressive girls from quitting school or becoming pregnant. A girl in either situation often becomes an underaged parent living in poverty, too stressed to provide the nurture children need. And this, Mr. Goldberg says, is the classic Petri dish that sprouts childhood aggression in either sex.

"We have to stop the intergenerational transmission of aggression," he says. "And here, one of the best strategies is to keep young girls in school and out of trouble."

DUXBURY, Mass. (AP) - Two 15-year-old girls face hate crime charges for allegedly shooting red and green paint balls at the home of a Jewish family and condemning the family for not decorating the house for Christmas.

One member of the family targeted in the Dec. 17 incident is a teacher in the Duxbury schools and had taught at least one of the girls, Detective Susan Manning said Tuesday.

A one-sentence note found at the scene said: ``This is what happens when you don't decorate for Christmas.''

The family is ``terrified and extremely concerned,'' Manning said.

The two Duxbury High School sophomores have been suspended from school. Police said they will be arraigned in juvenile court later this week or early next week. They were not identified because of their age.