🔗 Share this article

"What was the price did Santa's sled cost? Nothing, it was on the house."

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

We're at a joke-testing meeting with a firm that makes products for gatherings. Its repertoire features festive crackers.

The firm's founder grins, nearly sheepishly at the joke. But the joke has been selected and will appear in upcoming crackers.

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

The key to a good holiday cracker joke is not the same as a stand-up gag per se. It is entirely about the setting - in this instance, the communal laughter of the Christmas dinner table with elders, children and possibly friends.

"You want the joke to be a thing that brings the eight-year-old in harmony with the 80-year-old," she adds.

The Neuroscience Of Communal Amusement

Coming together to enjoy shared laughter is not only nothing new, experts argue, it is probably to be pre-human.

"So when you are chuckling with others around the Christmas dinner you are dropping into what's almost certainly a really primordial mammalian social vocalisation," explains a neuroscience expert.

Shared amusement, she says, aids in make and maintain social bonds between people.

Researchers have found that a lack of these social exchanges can significantly harm both psychological and bodily well-being.

"Those you converse with, and laugh with, it leads to enhanced amounts of 'happy chemical' uptake," she adds.

These natural chemicals 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 friends over a particularly terrible Christmas cracker joke.

"It's not simply laughing at a foolish joke with a Christmas cracker," she states. "You are actually doing a lot of the really important task of building, preserving the social bonds you have with the people you care about."

Which Happens In the Mind?

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

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

Employing 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 map the regions that receive more blood.

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

"During the study we observed a really interesting pattern of activation," says the neuroscientist.

A gag activates not just the areas of the mind responsible for hearing and understanding language, but also neural areas associated with both planning and starting motion and those linked to sight and memory.

Put these elements together, and people listening to a joke have a sophisticated set of neural responses that underpin the laughter we hear.

The Contagious Nature of Chuckles

Researchers discovered that when a humorous phrase is combined with chuckles there is a greater reaction in the brain than the same phrase when followed by a non-emotional sound.

"This activation occurred in areas of the mind that you would use to contort your face into a smile or a laugh," the professor explains.

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

Amusement, according to the professor, can be infectious.

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

"People laugh harder when you are familiar with people," she says, "and laughter increases further when you are fond of them or love them."

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

"The laughter is key. The gag is the terrible Christmas cracker joke, and it's just a reason to laugh as a group."

The Search for the Ideal Cracker Joke

Is it possible to discover the perfect gag?

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

Years ago, a professor established a scientific search for the planet's most humorous joke.

Over 40,000 jokes later, with ratings provided by 350,000 people globally, he has a clearer understanding than most as to what succeeds and what fails.

The perfect festive cracker joke needs to be short, he says.

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

The more "terrible" the joke, he says the better.

"This is because if no-one laughs – it's the joke's fault, not yours.

"The fascinating part about the holiday cracker puns is that none of us find them funny.

"That's a shared experience around the table and I think it's wonderful."