🔗 Share this article

"How much did Santa's sleigh cost? Nothing, it was on the house."

This joke is met by moans that echo through a storage facility in London.

This describes a joke-testing session with a firm that makes supplies for social events. Its catalogue includes festive crackers.

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

"The success is gauged by the joke by the volume of groans and the loudness of the groans around the table," the founder explains.

The key to a good Christmas cracker pun is not the identical as a stand-up gag in itself. It is entirely about the setting - in this case, the communal laughter of the Christmas dinner table with grandparents, kids and possibly friends.

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

The Science Behind Communal Laughter

Gathering to enjoy shared laughter is not only ancient, scientists argue, it is likely to be older than humanity.

"Therefore when you are laughing with people at the Christmas dinner you are engaging in what's very likely a truly ancient mammalian play vocalisation," says a neuroscience expert.

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

Researchers have found that a absence of such social exchanges can seriously damage both psychological and bodily well-being.

"The people you talk to, and share laughter with, it results in increased levels of 'happy chemical' release," the professor continues.

These natural chemicals are the body's "feel-good compounds" and are released both to alleviate tension and discomfort and in response to pleasurable activities, such as chuckling with loved ones over a particularly awful festive cracker gag.

"You're not just chuckling at a foolish pun with a holiday cracker," she says. "You are actually performing a lot of the truly vital work of making, maintaining the connections you have with those you love."

What Happens Inside the Brain?

But what is truly happening within the brain when we listen to a joke?

A tremendous amount happens in reaction to humour, it transpires.

Using brain scanning technology, a kind of brain scanner which indicates which areas of the brain are working harder, scientists have been able to map the regions that get more blood flow.

The research involves imaging the brains of volunteer subjects and then exposing them to a collection of funny words, accompanied by either a non-emotional sound, or pre-recorded chuckles.

"In the scanner we got a very interesting activation pattern of activation," notes the neuroscientist.

A gag activates not just the areas of the mind in charge of hearing and understanding speech, but also brain areas involved in both preparation and initiating motion and those involved in vision and recall.

Put all of this together, and individuals listening to a pun have a sophisticated series of neural responses that support the amusement we hear.

The Contagious Nature of Chuckles

Scientists discovered that when a funny phrase is paired with chuckles there is a greater reaction in the brain than the identical word when accompanied by a neutral sound.

"This activation occurred in parts of the brain that you would use to move your expression into a grin or a chuckle," the professor says.

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

Laughter, says the professor, can be contagious.

So what does this mean for the laughter found around a holiday table?

"People laugh harder when you know people," she notes, "and laughter increases further when you are fond of them or care for them."

When it comes to Christmas cracker jokes, she says, the feel-good effect is more probable to be caused not by the gag itself, but from the response to it.

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

The Search for the Perfect Festive Pun

Will we ever discover the ultimate gag?

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

Years ago, a psychologist established a scientific project for the planet's most humorous gag.

Over tens of thousands of gags later, with scores lodged by 350,000 participants around the world, he has a better idea than most as to what succeeds and what fails.

The ideal Christmas cracker pun must be short, he says.

"But they also be bad gags, jokes that make us moan," he adds.

The more "awful" the gag, he says the more effective.

"This is because if nobody finds it funny – it's the joke's fault, not your own.

"The fascinating part about the holiday cracker puns is that not one person find them funny.

"It creates a shared moment at the gathering and I think it's lovely."