What Do Christmas Cracker Gags Influence Our Brains?

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

This quip is met by groans that echo through a storage facility in London.

This describes a humor-evaluation meeting with a firm that makes supplies for gatherings. Its catalogue features festive crackers.

The firm's owner smiles, nearly apologetically at the joke. But the pun has been selected and will appear in future crackers.

"The success is gauged by the joke by the number of groans and the intensity of the groans at the table," she explains.

The key to a great Christmas cracker joke is not the same as a good gag per se. It is all about the setting - in this instance, the communal amusement of the holiday meal with grandparents, children and potentially friends.

"You want the joke to be something that brings the eight-year-old together with the grandparent," she adds.

The Neuroscience Behind Communal Amusement

Coming together to experience communal amusement is not only ancient, scientists say, it is probably to be pre-human.

"Therefore when you are laughing with people around the holiday table you are engaging in what's very likely a truly ancient mammalian social vocalisation," explains a neuroscience expert.

Shared amusement, she explains, aids in forge and strengthen social bonds between people.

Scientists have discovered that a lack of such social exchanges can significantly harm both psychological and bodily well-being.

"The people you talk to, and share laughter with, it results in enhanced amounts of 'happy chemical' uptake," the professor continues.

These natural chemicals are the body's "happy chemicals" and are produced both to alleviate tension and discomfort and in response to pleasurable activities, such as chuckling with loved ones over a particularly awful festive cracker gag.

"You're not just laughing at a silly pun with a Christmas cracker," the expert says. "You are in fact doing a lot of the really vital work of building, preserving the connections you have with those you care about."

What Occurs Inside the Mind?

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

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

Employing brain scanning technology, a kind of neural imager which shows which parts of the brain are more active, researchers have been able to map the areas that get more blood flow.

The research entails imaging the brains of healthy participants and then exposing them to a collection of humorous words, accompanied by either a neutral sound, or recorded chuckles.

"In the scanner we observed a really fascinating activation pattern of activation," notes the neuroscientist.

A joke stimulates not just the parts of the brain responsible for hearing and understanding speech, but also brain regions involved in both planning and starting movement and those involved in sight and recall.

Put these elements together, and individuals hearing a pun have a sophisticated series of brain responses that underpin the amusement we hear.

The Contagious Power of Laughter

Scientists discovered that when a humorous word is combined with laughter there is a stronger reaction in the brain than the same phrase when followed by a neutral sound.

"This was in areas of the mind that you would employ to contort your face into a grin or a laugh," she says.

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

Amusement, says the expert, can be contagious.

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

"You laugh harder 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 puns, she says, the feel-good effect is more likely to be triggered not by the gag in itself, but from the reaction to it.

"The laughter is key. The gag is the dreadful holiday cracker joke, and it's just a pretext to laugh as a group."

The Search for the Ideal Festive Pun

Is it possible to discover the perfect gag?

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

Years ago, a psychologist established a scientific search for the world's most humorous joke.

More than tens of thousands of jokes later, with ratings lodged by hundreds of thousands of participants globally, he has a better idea than many as to what works and what does not.

The perfect festive cracker pun must be short, he says.

"They must also be bad gags, puns that make us groan," he adds.

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

"This is because if nobody laughs – it's the joke's fault, not yours.

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

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