🔗 Share this article

"What was the price did Father Christmas's sleigh cost? Nothing, it was on the house."

This joke is met by groans that echo through a warehouse in London.

This describes a humor-evaluation meeting with a firm that makes supplies for gatherings. Its repertoire features Christmas crackers.

The firm's owner smiles, almost sheepishly at the joke. But the joke has made the cut and will appear in future crackers.

"You measure the gag by the volume of moans and the loudness of the groans around the table," the founder explains.

The secret to a great holiday cracker joke is not the identical as a stand-up gag in itself. It is entirely about the setting - in this instance, the shared amusement of the Christmas dinner table with grandparents, children and possibly neighbours.

"You want the joke to be something that unites the child in harmony with the 80-year-old," she adds.

The Neuroscience Behind Shared Laughter

Gathering to experience communal laughter is not only ancient, scientists say, it is likely to be older than humanity.

"Therefore when you are laughing with people around the Christmas dinner you are dropping into what's very likely a truly primordial mammalian social sound," says a neuroscience expert.

Shared laughter, she explains, helps make and maintain social connections between individuals.

Researchers have found that a absence of such social exchanges can seriously damage mental and physical well-being.

"The people you talk to, and share laughter with, it leads to enhanced levels of 'happy chemical' uptake," the professor continues.

These natural chemicals are the body's "feel-good compounds" and are produced both to reduce stress and pain and in response to pleasurable experiences, such as laughing with friends over a particularly awful festive cracker gag.

"You're not just chuckling at a foolish joke with a Christmas cracker," she says. "You are in fact performing a lot of the really vital work of building, preserving the connections you have with the people you care about."

Which Happens Inside the Brain?

But what is truly happening inside the mind when we hear a joke?

An awful lot occurs in reaction to humour, it turns out.

Employing functional magnetic resonance imaging (fMRI), a kind of neural imager which indicates which parts of the brain are more active, scientists have been able to map the regions that receive more blood flow.

Testing involves imaging the brains of volunteer subjects and then subjecting them to a database of humorous words, paired with either a non-emotional sound, or pre-recorded chuckles.

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

A joke stimulates not just the areas of the mind in charge of auditory processing and understanding language, but also brain regions involved in both planning and starting movement and those linked to vision and memory.

Put all of this together, and people hearing a joke have a sophisticated set of neural responses that underpin the laughter we experience.

The Contagious Power of Chuckles

Researchers found that when a humorous phrase is combined with chuckles there is a stronger reaction in the mind than the identical phrase when followed by a non-emotional sound.

"This was in areas of the brain that you would employ to move your face into a smile or a chuckle," she explains.

It indicates we are not just reacting to humorous jokes, they are responding to the amusement that follows them.

Laughter, according to the professor, can be infectious.

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

"People laugh harder when you are familiar with others," she says, "and you laugh more when you are fond of them or love them."

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

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

The Quest for the Perfect Festive Pun

Is it possible to find the perfect gag?

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

In 2001, a psychologist set up a research project for the world's funniest gag.

More than 40,000 gags later, with scores provided by 350,000 participants globally, he has a better idea than many as to what succeeds and what does not.

The ideal Christmas cracker joke needs to be brief, he says.

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

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

"The reason is that if nobody finds it funny – it's the gag's shortcoming, not yours.

"The fascinating part about the holiday cracker jokes is that not one person considers them humorous.

"It creates a shared moment at the table and I believe it's lovely."