🔗 Share this article

"How much did Santa's sled cost? Zero, it was on the house."

This one-liner is met by groans that resonate through a storage facility in London.

This describes a joke-testing session with a company that makes supplies for gatherings. Its catalogue includes festive crackers.

The company's owner smiles, almost sheepishly at the gag. But the pun has made the cut and will feature in future crackers.

"The success is gauged by the joke by the number of moans and the intensity of the groans at the table," the founder says.

The key to a good holiday cracker joke is not the same as a good gag in itself. It is entirely about the context - in this case, the communal amusement of the Christmas meal with elders, kids and potentially friends.

"You want the joke to be a thing that unites the eight-year-old in harmony with the grandparent," she states.

The Science Of Communal Amusement

Coming together to enjoy shared amusement is not only ancient, experts say, it is likely to be pre-human.

"Therefore when you are laughing with people around the holiday table you are engaging in what's very likely a really primordial mammal social sound," says a professor.

Shared laughter, she explains, helps forge and strengthen social bonds between individuals.

Researchers have discovered that a lack of such interactions can seriously harm both psychological and bodily well-being.

"Those you converse with, and share laughter with, it leads to increased levels of endorphin release," the professor continues.

Endorphins are the brain's "happy chemicals" and are produced both to alleviate tension and discomfort and in reaction to enjoyable experiences, such as laughing with loved ones over a particularly awful Christmas cracker joke.

"You're not just chuckling at a silly joke with a Christmas cracker," the expert states. "You are actually performing a lot of the truly vital work of making, maintaining the social bonds you have with the people you love."

What Happens Inside the Brain?

But what is actually taking place within the brain when we listen to a joke?

An awful lot happens in response to humour, it transpires.

Employing brain scanning technology, a kind of brain scanner which indicates which parts of the mind are working harder, scientists have been able to chart the regions that get more blood flow.

The research entails imaging the brains of volunteer subjects and then exposing them to a database of funny phrases, paired with either a neutral sound, or recorded chuckles.

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

A gag activates not just the areas of the brain responsible for auditory processing and understanding speech, but also brain regions associated with both planning and starting motion and those linked to vision and recall.

Combine these elements together, and individuals listening to a joke have a sophisticated series of neural reactions that support the amusement we hear.

The Infectious Nature of Laughter

Scientists discovered that when a funny word is combined with laughter there is a greater reaction in the brain than the same phrase when followed by a neutral sound.

"This was in parts of the mind that you would employ to move your face into a smile or a laugh," she says.

It means people are not just responding to funny jokes, they are reacting to the laughter that follows them.

Laughter, says the expert, can be infectious.

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

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

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

"The laughter is key. The gag is the terrible holiday cracker pun, and it's just a pretext to laugh as a group."

The Search for the Perfect Cracker Joke

Will we ever discover the perfect joke?

Likely not, but that has not prevented experts from trying to.

Years ago, a professor established a scientific project for the world's most humorous joke.

More than 40,000 gags submitted, with ratings provided by 350,000 participants around the world, he has a clearer idea than most as to what works and what fails.

The ideal festive cracker pun must be brief, he explains.

"But they also need to be bad gags, puns that make us moan," he continues.

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

"This is because if no-one laughs – it's the gag's shortcoming, not your own.

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

"That's a common experience around the table and I believe it's lovely."