Are you alright, Miss Townshend?”

“I’m fine, Felicity, just looking for something,” I say, randomly picking up and putting down items on my desk, acutely aware of 30 sets of bright, curious eyes trained on my back.

And it’s true. I am fine. But I’m also having a normal, human reaction to a film we’ve just watched about the First World War Christmas Day football match. (Yes, I know it was a TV advert designed to sell groceries!) It’s been a long, hard week and watching this story, which has the power to touch the hardest of hearts, my eyes have filled with tears.

I’ve never been one to preach a stiff upper lip: I was crying during those adverts for abandoned puppies way before it was cool, and I’m very much from the wishy-washy liberal arts student emotions-are-good school of thought. But the second I realise that my class might actually notice me crying, I find myself desperate to hide it.

The irony here is that although I may not intellectually subscribe to the stiff-upper-lip theory, clearly on some visceral level I’ve absorbed it pretty deeply - so deeply that I’d rather pretend to knock a full pot of pencil sharpenings on to the floor than display this vulnerability to my students.

But why should this be the case? One argument goes that the core of my job is to provide an environment in which my pupils feel completely safe and secure; a teacher who has lost control of their own emotions, even in the gentlest of ways, could lose control of so much more. It’s the myth that no matter what happens, your teacher has got this.

And it’s a compelling argument to a certain extent. Clearly, full-on ugly crying when your dog dies or when you’ve had a tough observation, or just because you’re full of Tuesday morning existential despair, is probably a no-no. As is hiding under your desk and rocking when you realise that the science investigation involving sand, water and soil, and a class of giddy six-year-olds, was not the stroke of organised genius you first thought.

Part of teaching is about wearing your game face - and, with your game face, you can’t always afford to give every emotional nuance away. There’s a reason why we might be keen to keep those emotional gates tightly closed, lest a trickle becomes a flood. And it’s clearly not fair to burden children with adult emotions that they can’t understand and aren’t responsible for.

But I’ve always believed that teaching is also a bit about being the change you want to see in the world. (And even after 10 years in the profession, some of this idealism stubbornly persists.) I want the children I teach to know that it’s alright for them to be sad sometimes - that it’s alright to feel overwhelmed by how hard it can be to live in this world - that it’s OK to show other people this and expect kindness and understanding rather than ridicule. If I can’t shed a tear when my long-standing colleague leaves the school, what does this tell the children about the acceptability of their emotions? And if part of what I’m trying to teach them is that war is sad and horrible, then why shouldn’t I have an authentically sad reaction when we examine certain aspects of war?

It’s not just in the abstract either. I probably wouldn’t actually cry while doing it, but I’ve come to believe that telling a child that their behaviour has made you sad can be a powerful tool when it comes to demonstrating a co-mingled displeasure with a behaviour and a need to show you still care. Sometimes being open about our more challenging emotions can show children how their actions have their own butterfly effect.

No teacher can afford to be sentimental about children, who are just as capable of sneering cruelty as adults, sadly. But they are also just as capable of genuine kindness. And even after I’ve fiddled with the items on my desk and turned around to address the class again, there’s a certain shininess to my eyes, I suspect, that suggests I haven’t entirely got away with things. The discussion that follows this demonstrates a level of maturity and sombre reflection from my Year 3 class that could quite easily make me cry again. And I wonder if part of this is about seeing their teacher visibly moved, which provides a meaningful context to the film that it probably couldn’t achieve on its own.

Anger can be a comfort

It’s not just about crying, though. While tears rolling down cheeks are a visible crossed line for most of us, this incident has made me think about the delicate balance involved in teaching … and it’s made me examine that balance in my own practice more, too. Because it’s a profession about relationships, to a large extent, and for relationships to work, there needs to be some authenticity in our interactions. Yet, as I’ve established above, so much of teaching is based on performance.

So, having wondered about the acceptability of showing signs of genuine sadness in the classroom, I find myself asking similar questions about other emotions.

Many of us will have been taught during training that one of the key tenets of behaviour management is that it’s better to pretend to be angry than to actually be angry. If you’re actually angry or upset about a student’s behaviour, then your decision making will be impaired and your capacity to deal with it will be reduced.

There have certainly been occasions over the years when I’ve felt genuine anger and frustration descend, and I know that I’ve made mistakes in how I’ve dealt with things. A cool head almost certainly wins most days. Yet I still believe there are exceptions to the rule. Many years ago, while doing regular supply work in a school, I found a group of children who had discovered a birds’ nest in a bush, pulled it down and broken each and every one of the perfect, miniature, speckle-covered eggs. I’m not convinced that anything other than genuine anger at that point could have communicated to them so clearly the gravity - and finality - of what they had done.

I’ve seen similar - and, importantly, rare - displays of anger from other teachers throughout my career when dealing with issues such as bullying or wilful, mindless vandalism. And they are incidents that have remained with me, that have made an impression. They make an impression on children in a wider sense, too. If you show genuine anger at spiteful, hurtful behaviour from a few children, then you send the message to the rest of them that this is serious, not to be tolerated. And, in this sense, anger from an adult can be a comfort - a reminder that justice is sometimes actually done.

Again, there are limits. Rampaging around the classroom like a frustrated rock star, smashing chairs and tables, sounds like a swift route to disqualification from the profession. And teachers who carry too much anger near the surface, ever-ready to kindle into life at the slightest misdemeanour, can be genuinely destructive forces on young minds.

But this should not mean that a teacher should never show anger in any circumstance. And somewhere between sadness and anger lies that most fabled strategy of adults everywhere: disappointment. I remember, vividly, the incidents in my own childhood where I disappointed the adults I admired and respected. And that remembrance is proof enough that sometimes emotional responses have an effect - for better or for worse.

It’s an odd thing that teachers are encouraged - and even expected - to model authentic, positive emotion every day. We are supposed to show genuine excitement about every lesson we teach, genuine happiness about every tiny step of success a student makes. But any negative emotions we might feel are supposed to be hidden or merely adopted as an appearance on the surface for impact.

A show of authenticity

The thing is, though, children are not stupid. And it comes back down to this idea of authenticity. Sometimes allowing children a glimpse of our real emotions, even the less positive ones, allows them to see us as humans - older, wiser humans who they can trust to keep them safe, but humans nonetheless.

There’s a TED Talk called, appropriately enough, “The Power of Vulnerability”, which has been widely cited in discussions about mental health and empathy in recent years; it offers the example of someone being trapped down a hole and members of the public walking past, calling down well-meaning platitudes of support as they do so. Help only really comes when someone finally goes to sit in the hole with them - to share something genuine and meaningful - and crucially to be vulnerable themselves in doing so.

With every proviso and acceptable context attached, we owe the children we teach no less than this. And that means letting ourselves display sadness and frustration and, yes, sometimes even anger.

Next time I’m moved to tears by something at school (and there almost certainly will be a next time), I hope I’m brave enough to tell my children that I’m fine, but a bit sad. And I hope that this will teach them that it’s OK to be a bit sad sometimes, too.

Because, y’know, it is.

Kate Townshend is a teacher in Gloucestershire. She tweets @_KateTownshend