🔗 Share this article

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

This one-liner is greeted with moans that echo through a storage facility in the capital.

We're at a humor-evaluation session with a company that makes supplies for gatherings. Its catalogue features festive crackers.

The company's owner smiles, almost sheepishly at the gag. But the pun has been selected and will appear in future crackers.

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

The key to a good holiday cracker pun is not the identical as a stand-up gag per se. It is entirely about the context - in this case, the communal amusement of the holiday meal with grandparents, kids and potentially friends.

"The goal is for the joke to be something that unites the child in harmony with the grandparent," she adds.

The Science Behind Shared Amusement

Gathering to experience communal amusement is not only ancient, experts say, it is likely to be pre-human.

"So when you are laughing with people around the Christmas table you are dropping into what's very likely a really primordial mammalian play vocalisation," explains a neuroscience expert.

Shared amusement, she says, aids in forge and strengthen social connections between people.

Researchers have discovered that a lack of these social exchanges can significantly damage mental and physical well-being.

"Those you converse with, and laugh with, it leads to increased amounts of 'happy chemical' release," she continues.

Endorphins are the brain's "feel-good compounds" and are produced both to alleviate stress and pain and in reaction to enjoyable experiences, such as laughing with loved ones over a particularly awful festive cracker gag.

"You're not just chuckling at a foolish pun with a Christmas cracker," the expert says. "You are in fact doing a lot of the truly vital work of making, maintaining the connections you have with those you love."

Which Happens In the Mind?

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

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

Using brain scanning technology, a type of brain scanner which shows which areas of the mind are more active, researchers have been able to map the areas that receive more blood.

Testing involves imaging the brains of volunteer subjects and then exposing them to a collection of humorous phrases, accompanied by either a non-emotional sound, or recorded laughter.

"During the study we got a very fascinating pattern of activation," notes the professor.

A joke stimulates not just the parts of the mind responsible for hearing and interpreting language, but also neural regions involved in both planning and starting motion and those linked to sight and recall.

Combine all of this as a whole, and people listening to a joke have a complex set of neural responses that support the amusement we hear.

The Infectious Power of Chuckles

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

"This activation occurred in areas of the brain that you would employ to contort your face into a grin or a chuckle," she says.

It means we are not just responding to humorous jokes, they are reacting to the laughter that accompanies them.

Laughter, says the professor, can be contagious.

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

"You laugh more when you know people," she says, "and laughter increases further when you are fond of them or care for them."

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

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

The Quest for the Perfect Cracker Joke

Is it possible to find the perfect joke?

Likely not, but that has not prevented experts 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 lodged by 350,000 participants around the world, he has a clearer understanding than most as to what succeeds and what does not.

The perfect Christmas cracker joke must be brief, he explains.

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

The increasingly "awful" the joke, he states the more effective.

"The reason is that if no-one finds it funny – it's the gag's fault, not yours.

"What's interesting about the holiday cracker jokes is that none of us find them humorous.

"It creates a shared moment around the gathering and I believe it's wonderful."