How Do Festive Cracker Jokes Affect Our Brains?

"How much did Santa's sleigh cost? Zero, it was on the house."

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

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

The company's founder smiles, nearly sheepishly at the gag. But the joke has been selected and will feature in future crackers.

"The success is gauged by the joke by the volume of groans and the loudness of the groans at the table," the founder says.

The secret to a great Christmas cracker pun is not the identical as a good joke in itself. It is entirely about the context - in this instance, the shared amusement of the holiday meal with elders, kids and possibly friends.

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

The Neuroscience Of Shared Laughter

Gathering to experience shared laughter is not only nothing new, scientists argue, it is probably to be older than humanity.

"Therefore when you are chuckling with others around the holiday dinner you are dropping into what's very likely a really ancient mammal play sound," explains a neuroscience expert.

Communal laughter, she explains, aids in make and maintain social connections between individuals.

Scientists have found that a lack of such social exchanges can significantly damage both psychological and bodily health.

"The people you converse with, and share laughter with, it results in increased amounts of 'happy chemical' release," she continues.

Endorphins are the brain's "happy chemicals" and are released both to alleviate tension and discomfort 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 silly pun with a Christmas cracker," the expert states. "You are in fact performing a lot of the really important task of building, preserving the connections you have with those you love."

What Happens Inside the Brain?

But what is actually taking place within the mind when we listen to a joke?

A tremendous amount occurs in response to humour, it transpires.

Employing brain scanning technology, a kind of neural imager which shows which areas of the brain are working harder, scientists have been able to chart the regions that receive more blood flow.

Testing entails imaging the minds of volunteer subjects and then subjecting them to a database of humorous words, paired with either a neutral sound, or pre-recorded laughter.

"During the study we got a really interesting pattern of activation," notes the neuroscientist.

A joke activates not just the parts of the brain in charge of auditory processing and interpreting language, but also brain areas associated with both planning and initiating motion and those linked to sight and memory.

Combine all of this as a whole, and people hearing a joke have a complex series of neural reactions that underpin the amusement we experience.

The Contagious Nature of Laughter

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 parts of the mind that you would use to contort your expression into a smile or a laugh," the professor says.

It indicates we are not just responding to humorous words, they are responding to the amusement that accompanies them.

Laughter, says the expert, can be infectious.

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

"People laugh harder when you are familiar with others," she says, "and you laugh 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 probable to be caused not by the gag in itself, but from the reaction to it.

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

The Search for the Ideal Festive Pun

Will we ever discover the perfect joke?

Probably not, but that has not prevented experts from trying to.

Years ago, a psychologist set up a research search for the planet's funniest gag.

More than 40,000 gags later, with scores provided by hundreds of thousands of participants globally, he has a clearer understanding than most as to what succeeds and what does not.

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

"They must also be poor gags, puns that make us moan," he adds.

The increasingly "terrible" the gag, he says the more effective.

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

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

"That's a common moment at the gathering and I think it's wonderful."