The County Court this week heard the case of four teenagers who brutally and relentlessly assaulted a girl with an intellectual disability in St Albans. During the 30-minute assault, the 16-year-old victim was punched, kicked, bashed with sticks and had her head slammed against the ground.

While the case is in every way horrific, what has made it so newsworthy is the fact that three of the 13-to-16-year-old perpetrators were girls. And what makes it even more sickening is that the 14-year-old’s mother helped plan the attack and then cheered on the children while taping the assault on a mobile phone for later broadcast on MySpace.

Also this week, 25-year-old Amber Cooper has appeared in the Melbourne Magistrates Court charged with the stabbing murder of a blind 65-year-old woman. The older woman was walking her two dogs mid-morning when she was stabbed in the throat, dying in a quiet Bairnsdale street.

Put the cases together and it would seem that we are witnessing an increase in violent attacks on girls and women, by girls and women. When did females become so nasty to each other?

Recent research out of the Queensland University of Technology reported that the rate of violent crime at the hands of girls tripled between 1989 and 2007. Violent crime by boys doubled in this period.

The causes of this trend to violence are undoubtedly complex and varied. Among the factors being blamed are TV, film, computer games and music, increased access to drugs and alcohol, changing attitudes to violence on a broader scale, and females trying to emulate male behaviour. Another widely touted theory puts cyberspace squarely in the frame.

Back when I was at school, girls could be incredibly mean and bitchy. Abuse took mainly indirect forms — name calling, gossip, perpetuating rumours and social exclusion. Today, technology is the new weapon in the bully’s armoury, giving them a whole more sinister approach.

Where our bullying would mostly stop at the school gate, with a click of a button today’s bullies can spread humiliating messages and degrading photos or videos throughout the virtual world. Bullying can be anonymous (which suits many girls who shy away from direct confrontation) and rather than be confined to school hours, the abuse can continue all day, every day.

In the case of the teenagers and mother mentioned earlier, it would almost seem that the technology has a part in driving the crime (although alcohol certainly played a role). Just have a look at the internet and it is clear that some girls are finding violence increasingly exciting and are showing off their skills in “bitch fight” videos online. The popularity of such clips on YouTube is staggering, with many videos indicating they have been played hundreds of thousands of times.

But it’s not just other teenagers who seem to find something intriguing about females who commit violence. At a broader level we condemn such acts and demonise the women involved, yet we happily lap up the stories in all their sickening detail. From Britains Moors murderer Myra Hindley to Australia’s own “black widow” Katherine Knight, and now Amber Cooper and the mother of the teenager in St Albans, their stories arouse a peculiar kind of morbid curiosity. Girls are meant to be gentle and protective. Mothers are meant to be incapable of such horrific acts.

On hearing of female violence, we gasp in collective horror — our anger and hatred not so much about the act itself, but about those girls and women defying the role we have created for them as soft, passive and conciliatory. If this most fundamental rule of our society falls over, it is as if all hell could break lose. Then begins the relentless speculation: what kind of woman commits such an act? What could possibly be her motive? What, we ask, does is say about our society that we created such a monster? Men who commit such acts, on the other hand, are spared the dissection. Familiarity with male-led violence means it sadly barely raises an eyebrow.

The rise in violence by women and girls is unquestioningly worrying and a bit scary. However, by getting hysterical, concentrating on the gender of the perpetrators and turning them into curiosities, we lose sight of the big picture. Females still represent the minority of violent offences and are at least 10 times more likely to be the victims of assault than males. Where we need to focus our attention is on the reasons why men and women, boys and girls use violent acts to assert power and resolve conflict. Only then can we begin to protect the most vulnerable members of our society.