How Do Holiday Cracker Gags Influence The Brain?

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

This one-liner is met by moans that resonate through a warehouse in the capital.

We're at a humor-evaluation meeting with a firm that makes products for social events. Its catalogue features Christmas crackers.

The company's owner smiles, almost apologetically at the joke. But the pun has been selected and will feature in future crackers.

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

The secret to a good Christmas cracker pun is not the identical as a stand-up joke in itself. It is all about the context - in this instance, the shared laughter of the holiday meal with elders, children and potentially neighbours.

"You want the joke to be something that brings the child together with the grandparent," she states.

The Science Behind Communal Amusement

Coming together to experience communal amusement is not only nothing new, scientists say, it is probably to be pre-human.

"So when you are chuckling with people at the Christmas dinner you are dropping into what's very likely a really ancient mammalian play vocalisation," explains a neuroscience expert.

Communal amusement, she says, helps forge and strengthen social connections between individuals.

Scientists have discovered that a lack of these interactions can seriously damage both psychological and bodily well-being.

"The people you talk to, and laugh with, it results in enhanced levels of 'happy chemical' release," the professor continues.

These natural chemicals are the brain's "happy chemicals" and are produced both to reduce tension and discomfort and in reaction to pleasurable experiences, such as laughing with friends over a truly terrible Christmas cracker joke.

"You're not just chuckling at a silly pun with a holiday cracker," she says. "You are actually performing a lot of the really vital work of building, preserving the connections you have with those you care about."

Which Happens Inside the Mind?

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

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

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

Testing involves scanning the brains of volunteer subjects and then exposing them to a database of humorous phrases, paired with either a non-emotional sound, or recorded chuckles.

"In the scanner we observed a really interesting pattern of activation," notes the professor.

A gag activates not just the areas of the mind responsible for auditory processing and interpreting speech, but also brain areas involved in both preparation and initiating motion and those involved in vision and memory.

Combine these elements together, and people hearing a pun have a complex series of brain reactions that support the amusement we experience.

The Contagious Nature of Laughter

Scientists found that when a funny word is paired with laughter there is a greater reaction in the mind than the same word when accompanied by a neutral sound.

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

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

Laughter, according to the professor, can be contagious.

So what does this imply for the laughter heard at a holiday gathering?

"People laugh more when you are familiar with others," she notes, "and laughter increases further when you like them or care for them."

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

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

The Search for the Ideal Festive Pun

Will we ever discover the ultimate gag?

Likely not, but that has not stopped experts from attempting to.

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

Over 40,000 gags submitted, with ratings lodged by hundreds of thousands of people globally, he has a better understanding than most as to what works and what fails.

The ideal Christmas cracker joke needs to be short, he explains.

"They must also need to be poor jokes, puns that cause us to groan," he adds.

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

"This is because 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.

"That's a common moment at the gathering and I believe it's lovely."