🔗 Share this article

"How much did Father Christmas's sled cost? Nothing, it was on the house."

This joke is greeted with moans that echo through a warehouse in London.

We're at a joke-testing meeting with a firm that produces products for social events. Its catalogue features Christmas crackers.

The firm's founder grins, almost apologetically at the gag. But the pun has been selected and will appear in future crackers.

"The success is gauged by the joke by the number of groans and the intensity of the groans around the table," she explains.

The secret to a great Christmas cracker joke is not the identical as a good joke in itself. It is entirely about the context - in this instance, the communal amusement of the Christmas dinner table with elders, children and potentially neighbours.

"The goal is for the joke to be something that brings the child together with the 80-year-old," she adds.

The Science Of Communal Laughter

Gathering to enjoy communal laughter is not only nothing new, scientists argue, it is probably to be older than humanity.

"So when you are laughing with others at the Christmas table you are dropping into what's very likely a really primordial mammalian social vocalisation," explains a professor.

Communal amusement, she says, helps forge and strengthen social connections between people.

Researchers have discovered that a absence of these interactions can significantly damage both psychological and bodily well-being.

"The people you converse with, and laugh with, it leads to enhanced levels of 'happy chemical' release," she continues.

Endorphins are the brain's "feel-good compounds" and are produced both to alleviate stress and pain and in reaction to pleasurable activities, such as laughing with loved ones over a particularly terrible festive cracker joke.

"You're not just laughing at a foolish pun with a holiday cracker," the expert states. "You are actually doing a lot of the really vital work of building, preserving the connections you have with those you love."

What Happens Inside the Brain?

But what is truly happening inside the brain when we hear a gag?

An awful lot occurs in reaction to comedy, it transpires.

Using functional magnetic resonance imaging (fMRI), a type of neural imager which shows which parts of the brain are more active, scientists have been able to chart the areas that receive more blood.

Testing involves imaging the brains of volunteer participants and then subjecting them to a database of humorous phrases, accompanied by either a neutral sound, or pre-recorded laughter.

"During the study we got a really interesting activation pattern of neural activity," notes the neuroscientist.

A joke activates not just the areas of the mind responsible for auditory processing and interpreting speech, but also neural regions associated with both preparation and initiating motion and those linked to vision and recall.

Put these elements together, and people hearing a joke have a sophisticated set of neural responses that support the amusement we experience.

The Contagious Power of Chuckles

Researchers found that when a humorous phrase is combined with laughter there is a greater reaction in the brain than the same phrase when accompanied by a non-emotional sound.

"This activation occurred in areas of the brain that you would employ to move your face into a smile or a laugh," the professor says.

It means people are not just reacting to humorous words, they are reacting to the amusement that accompanies them.

Amusement, according to the expert, can be infectious.

So what does this imply for the chuckles heard at a Christmas gathering?

"You laugh harder when you know others," she notes, "and you laugh further when you are fond of them or care for them."

When it comes to festive cracker puns, she explains, the positive factor is more probable to be triggered not by the gag itself, but from the response to it.

"The laughter is key. The gag is the terrible holiday cracker joke, and it's just a pretext to chuckle together."

The Quest for the Perfect Festive Pun

Will we ever discover the perfect joke?

Likely not, but that has not prevented researchers from attempting to.

In 2001, a psychologist set up a scientific project for the planet's most humorous joke.

More than tens of thousands of gags submitted, with scores provided by hundreds of thousands of participants around the world, he has a clearer idea than most as to what works and what fails.

The ideal Christmas cracker pun needs to be short, he says.

"But they also be poor jokes, jokes that cause us to moan," he continues.

The increasingly "awful" the joke, he states the better.

"The reason is that if nobody laughs – it's the joke's shortcoming, not your own.

"What's interesting about the Christmas cracker jokes is that none of us considers them humorous.

"It creates a common experience at the gathering and I think it's wonderful."