Last week I listened in horror as a friend told me about the 'mean girls' at her daughter's school. How they bullied, excluded, verbally abused, undermined and embarrassed her little girl.
Yes, little girl. The situation she was telling me about was happening in a primary school, and the perpetrators were seven and eight years old.
Later that same week, another friend told me a similar story; same scenario, same age group, just in a different part of the country.
Not for the first time it made me thank my lucky stars I have a son and not a daughter.
Their stories both followed the same patten; their daughter had originally been friends with the girl in question, but then, without warning or incident, things changed.
"We had regularly been having Laura home to tea, for sleepovers, everything," Jackie, mum of seven-year-old Hannah told me.
"Hannah considered her to be her best friend – they had been inseparable more or less since the first day of school, but then she suddenly dropped her for no reason and, to make it worse, seemed intend on jeopardising every new friendship Hannah tried to form."
Jackie told me Laura would immediately pal up with whoever Hannah played with, inviting them home to play, even bringing in little presents and 'best friend' cards – all the while whispering and gossiping about Hannah, mocking her shoes, her hair, her schoolbag, and even the way she spoke.
"It has been heartbreaking seeing Hannah go through this," Jackie said.
"She genuinely has no idea why Laura suddenly started on her – and nor do I. It's frightening to think a seven year old can be so calculating and manipulative – she has literally turned most of the girls in the class against Hannah."
At the other end of the country, Kirsty, mum of two little girls, Rosie, eight, and baby Alicia, one, was similarly fuming – but could not sit back and let the vendetta against her daughter continue.
"I was so fed up with how one girl was making life hell for Rosie that I had it out with her mother," Kirsty told me.
"Rosie had only been at her new school for a couple of weeks and was trying her best to fit in and make friends, and this one girl obviously took exception to that – she was lovely to Rosie at first and came round to ours for tea, but then immediately went back to school the next day slagging off our house, our food, Rosie's bedroom, clothes, toys... everything."
Kirsty said she encouraged Rosie to stick it out for a few days, confident that the other little girl would lose interest and stop picking on her. But she didn't, instead it got worse.
"She orchestrated a complete whispering campaign and basically told the other girls she would not be friends with them if they played with Rosie! The power eight-year-old girls have is just crazy."
Kirsty eventually spoke to the child's mother who hotly denied her daughter would 'ever' do anything like that. But despite her denials, the girl's behaviour did improve.
"I told the mother I would be going to the head teacher the following Monday if things continued, so she obviously had a word," Kirsty said.
"Rosie still gets 'the evils' from this other girl, but she's not constantly telling other girls not to sit next to her or partner her in PE now, thank god, and a few have now come round for tea. It is ridiculous though that this goes on."
As the mum of a son I found these stories more than just ridiculous – as grown women we can all remember horrid TEENAGE girls at school being just like this – but did it really start SO young? And why do girls seem to have this in-built capacity for such viciousness towards their own sex?
Parenting author Karen Sullivan says that girls are simply just 'meaner' than boys.
"It is the method they choose to fight their battles," Karen says, "Little girls are effectively struggling with identity and social relationships, and much of their behaviour is a way of making themselves look good, controlling their immediate environment, and exercising some personal power."
Karen says that ALL children do this – the genders just have different approaches.
"Girls do it in a controlling way that is often related to insecurity or powerlessness," she says, "And while boys fight with their fists, girls fight with their minds and tongues."
"Boys tend (generally speaking) to wear their hearts on their sleeves and react instantly to perceived threats, usually with physical aggression - air cleared, business as usual.
"However, girls tend to employ something called 'social aggression', which is much more likely to involve ostracising friends, gossip, sarcasm, bitchiness and cliques."
This, Karen says is much more hurtful to those on the receiving end, and can end up turning into a 'sustained, long-term campaign involving calculated abuse'.
So are girls worse than they used to be, as me and the mums I spoke to assume they are? Or do we just see things very differently as adults?
"There is an increasing culture of young women gaining 'respect' from the boys and other contemporaries by being violent, wild, engaging in risky behaviours, pushing boundaries and this is the culture in which today's little girls are growing up," Karen says. "It's OK to be mean and cruel; it's acceptable to use verbal violence and alienation as tools. It makes them feel strong, cool and powerful."
Karen says the problem is 'partly compounded in contemporary society by poor role models'.
"Girls are encouraged to be 'strong' and 'speak their minds'," she says, "There is a very strong ladette culture, many children have inconsistent or non-existent parenting in place and female qualities such as nurturing, kindness and gentleness are now perceived to be weaknesses rather than quiet strengths."
Karen also believed that television plays a part in making girls believe that some inappropriate behaviour is acceptable.
"There are a host of TV shows - often from America - where kids are mouthy, outspoken, rude and, yes, mean, to raise laughs, and this is the culture in which today's little girls are growing up thinking it's OK to be mean and cruel and acceptable to use verbal violence and alienation as tools. It makes them feel strong, cool and powerful."
So what is the answer to addressing the behaviour? Karen believes 'mean girls' need a combination of guidance and support and strong, positive role models.
"They need to be taught ways to assert themselves efficiently and effectively within socially acceptable parameters," she says, "They also need to be given a little power - some responsibility in the home or classroom, for example - in order to feel good about themselves. Most importantly, they need to be shown respect and treated with kindness, compassion and empathy so that these behaviours become learned."
But, she adds: "Mean girls are bullies, no matter how you look at it."
Something my two friends would no doubt agree with.
More on Parentdish: How to bullyproof your child
These videos below give tips on helping your child cope with bullies - and what to do if you suspect your child is a bully!