🔗 Share this article

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

This joke is met by groans that resonate through a warehouse in the capital.

We're at a humor-evaluation session with a firm that produces products for social events. Its catalogue features festive crackers.

The firm's founder grins, almost apologetically at the gag. But the joke has made the cut and will appear in upcoming crackers.

"You measure the gag by the number of groans and the loudness of the groans around the table," the founder says.

The secret to a great Christmas cracker pun is not the identical as a good joke per se. It is all about the setting - in this case, the communal amusement of the Christmas dinner table with grandparents, kids and potentially neighbours.

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

The Science Of Communal Laughter

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

"Therefore when you are laughing with others around the holiday dinner you are engaging in what's almost certainly a truly ancient mammalian play vocalisation," says a neuroscience expert.

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

Scientists have found that a lack of these interactions can significantly damage both psychological and bodily health.

"The people you talk to, and share laughter with, it leads to enhanced levels of endorphin release," she adds.

These natural chemicals are the body's "happy chemicals" and are produced both to alleviate tension and discomfort and in reaction to enjoyable activities, such as chuckling with friends over a truly awful festive cracker gag.

"It's not simply chuckling at a foolish pun with a holiday cracker," she states. "You are in fact doing a lot of the truly important work of building, preserving the social bonds you have with those you care about."

What Happens Inside the Mind?

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

An awful lot happens in reaction to comedy, it turns out.

Employing functional magnetic resonance imaging (fMRI), a type of neural imager which shows which areas of the brain are working harder, researchers have been able to map the areas that get more blood.

Testing entails scanning the brains of healthy subjects and then exposing them to a database of humorous words, accompanied by either a neutral sound, or pre-recorded chuckles.

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

A joke activates not just the parts of the brain responsible for hearing and interpreting language, but also neural areas involved in both preparation and starting motion and those linked to vision and memory.

Put all of this together, and people listening to a joke have a complex set of brain reactions that support the laughter we hear.

The Contagious Nature of Laughter

Researchers discovered that when a funny word is combined with chuckles there is a stronger reaction in the mind than the identical phrase when accompanied by a non-emotional sound.

"This activation occurred in parts of the brain that you would use to move your face into a smile or a chuckle," she says.

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

Amusement, according to the expert, can be contagious.

So what does this mean for the laughter found around a Christmas gathering?

"You laugh harder when you are familiar with others," she says, "and laughter increases more when you are fond of them or care for them."

When it comes to Christmas cracker jokes, she explains, the positive factor is more likely to be triggered not by the joke itself, but from the response to it.

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

The Search for the Ideal Cracker Joke

Will we ever find the perfect gag?

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

Years ago, a psychologist established a scientific search for the world's funniest gag.

More than 40,000 jokes submitted, with scores lodged by hundreds of thousands of participants around the world, he has a clearer understanding than many as to what succeeds and what does not.

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

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

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

"The reason is that if no-one laughs – it's the joke's shortcoming, not your own.

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

"That's a common moment around the gathering and I think it's lovely."