Just like the film Mean Girls, every school has its group of "plastics". We all know them, the swishy-haired girls with the handbags, laughing louder than a pack of hyenas and leaving the equivalent of a heavily scented crop spray in their wake.
They're a challenge for every teacher. They've mastered the eye roll with the hand on the hip and a ground-shaking sigh. They strut up and down corridors, periodically adopting catwalk poses to the admiration of their cronies, as other students attempt, chameleon-like, to blend in with the lockers so they don't become targets for the day.
You can hear these girls before they arrive in your classroom (they tend to possess loud voices). Once they are there, you will find them jockeying for position in the school social strata by being as mean as possible to everyone else.
This kind of behaviour has taken on a new dimension in recent years. The rise of the internet and mobile phones means that mean girls are effectively operating a 247 dictatorship. One incident I know of involved one girl stealing another's phone and texting her mother the message: "Sorry, mum, I'm pregnant". The fallout culminated in both mothers and both girls at each other's throats.
From the perspective of a pastoral leader, a clique can make or break a year group. In the past, I've witnessed 10 strong females and about 20 "sheep" intimidate staff and students alike - including physical bullying, emotional abuse, threats and bogus complaints. Male and female peers alike hardly dared to stick their heads above the parapet. Meanwhile, the mean girls constantly interrupted learning by holding court in lessons.
This wasn't just playground behaviour - these girls compromised the school ethos and examination performance, as well as destroying the emotional well-being of many students, particularly other girls.
Is this just a secondary school rite of passage? It would appear not, as friends of mine have commented that their daughters are experiencing mean-girl behaviour as early as infant school, where they have already been classified as "uncool".
Should schools interfere with students' cliques or is it just a fact of life that everyone will fall into a social group of some sort? Is learning to interact with different types of people just part and parcel of growing up?
A school's primary objective should be the safety and well-being of every student in its care. Tolerating such malevolent behaviour is tantamount to condoning bullying. While students are in our care, we have a duty to guide them in how to resolve conflict. Learning to navigate and manage social situations should be a part of growing up, but tolerating spiteful behaviour should not.
I have spoken to students about this issue and many say that they want leaders to discourage large groups from roaming around the school and for teachers take a tougher stance on such behaviour. So what are some practical solutions for a head of year?
l Know your year group and identify unhealthy friendships through regular discussion with tutors.
l Have an open and honest reconciliation process. If you have a school counsellor, use this resource.
l Be prepared to rejig your tutor groups. A natural opportunity to create a more harmonious balance comes at the end of key stage 3 as students move on to the next stage of their education.
l Conflict resolution should be on the curriculum for every year group as the nature and pressures of friendships change each year.
l Reinforce kindness and tolerance of others in assemblies. TrueTube has a lovely resource about random acts of kindness (bit.lyTrueTubeRandomActs).
l Instil a team ethos within your year group in the style of The Three Musketeers - all for one and one for all.
l Create a buddy system whereby older students are paired with Year 7 tutor groups to reinforce positive relationships through leading by example.
l Be consistent and persistent with the message that bullying will not be tolerated in any form.
Finally, renowned US journalist Dorothy Thompson has been credited with saying that "Peace is not the absence of conflict but the presence of creative alternatives for responding to conflict". We should all heed her advice.
Caroline Ross teaches in a secondary school in Hampshire
Use this lesson to examine the difference between positive and negative friendships. bit.lyPeerPressureBullying
Teachers TV looks at research into various methods of combating bullying.
Explore students' responses to peer pressure using these scenario cards.
Discuss bullying in assembly with a series of powerful short films on the topic.