During the recent BBC review of the country’s favourite sitcoms, I was coincidentally discovering how important humour is in our classrooms. When I asked headteachers and pupils to choose their best teachers and then explain their choices, a sense of humour was near the top of everyone’s list. This made me think about the role humour plays in learning.

Laughter is a learning lubricant. It increases the oxygen flow to the brain and releases endorphins - the feel-good chemicals. Smiling exercises our facial muscles (and saves on face cream and plastic surgery). Go to a laughter workshop and you will find that laughing makes you feel better, even if what you are laughing at is not that funny.

Laughter is also a social lubricant (with no toxic side-effects whatsoever). It is our way of communicating we are neither a threat nor threatened. When we laugh, we look at each other and so humour connects everyone into the loop. This is why humour is the best tool in the teacher’s ethos toolkit. Laughter synchronises the feelings of each member of the group and so promotes a shared sense of purpose.

We have all experienced the benefits of laughing in times of crisis.

Laughter, one of nature’s survival mechanisms, lets the brain work through upsetting experiences and helps keep them in perspective. There is no better way to handle difficult situations with pupils or colleagues.

Teachers don’t need to be stand-up comics. They don’t even need to be humorous. But teachers do need to be able to appreciate the value of humour. Not every teacher can “do humour”, but everyone can spot the witty pupils and accommodate the humour they create. Sometimes teachers fail to differentiate between the toxic and the friendly clown and too quickly suppress the latter.

Laughter in the classroom isn’t always helpful, of course. There is nothing more agitating than trying to dress down a group of pupils who won’t stop giggling. A smile becomes a smirk, a giggle becomes a snigger if you think pupils are laughing at you. It’s hard to appreciate that such nervous laughter is more often a natural reaction to a stressful situation than laughing at the teacher.

We are hard wired to copy each other so it’s extremely hard for pupils not to laugh when they see someone else laugh. It may be better to give pupils the space to process this, rather than take it as an affront. In the same way, because laughter is so infectious it is often best to let any hysterical fit of the giggles burn out or tune into the joke yourself and gradually bring the laughter down rather than demand immediate quiet.

Pupils certainly find being reprimanded for thinking things funny hard to take.

Warm personalised jokes about pupils are good ways of communicating that the teacher knows them well and recognises aspects of their personality.

Respectful banter and gentle teasing can work well, though there is a fine line between this and the cruel comedy of sarcasm that is at the expense of pupils. It’s all about laughing with, not at, pupils. At its best, humour builds reciprocity between teacher and pupils and so nurtures trust.

Sitcoms are funniest when we recognise the darker sides of our nature.

Consequently features like pomposity, agitation and aggravation are shared by our favourite characters, such as Basil Fawlty, Hyacinth Bucket, Captain Mainwaring and David Brent. Effective teachers are at the other end of this continuum, confident enough to be able to laugh even at the class mimic’s take-off of them.

Class comedy should never be cutting and so needs to be played by different rules from conventional comedy, based as it is on conflict and character flaws. Attempts at humour can backfire when the teacher tries too hard to be a pupil pleaser only to end up the class clown.

Fortunately there is plenty of suitable comic material at the teacher’s disposal such as the funny turn of phrase, facial expressions, imaginative use of props, gentle farce, incongruous situations and unexpected conclusions. The subtle art is to milk the joke and make learning enjoyable while keeping the class on task.

Humour works best within good relationships and in turn feeds what Bob Dylan called that “easy camaraderie”. It is both a sign and a nutrient of growing relationships. Humour blossoms when people are relaxed with each other and feel safe enough to be themselves. And a teacher who can appreciate classroom humour will be further relaxed through the shared laughter. It is the first thing to go when the teacher is stressed. The paradox is that stressed teachers who would benefit the most find it hard to let go of control and see the funny side.

Humour often involves teachers disclosing small bits of their personal lives and so lets pupils see they are human. Some teachers feel too threatened to “drop their guard” for fear pupils, if given an inch, will take a mile.

Most pupils “know the score”, however, and realise that the teacher-pupil relationship demands a certain status differential. In fact, teachers who can share humour appropriately with the class are less likely to have their authority challenged. This is because humour signals that the teacher doesn’t take things too seriously and so avoids any sense of superiority.

As J K Chesterton said, “angels can fly because they take themselves so lightly”.

I can still remember from my schooldays how we intuitively put our teachers through a “pomposity test”, such as the chain-smoking Jaguar driver who was asked if he bought his car with Embassy coupons. Classroom humour is important because it conveys so much about the teacher. It indicates whether the teacher is confident and wants to invite pupils into learning or is anxious to control pupils. Most significantly, it communicates what teachers think of themselves in relation to the class.

Where does all this leave the bleak yet still peddled advice to new teachers, “don’t smile till Christmas”?

Alan McLean is an educational psychologist in Glasgow.