What Do Christmas Cracker Puns Influence Our Brains?

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

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

This describes a humor-evaluation session with a firm that produces products for social events. Its repertoire features festive crackers.

The firm's owner grins, almost apologetically at the joke. But the joke has been selected and will appear in upcoming crackers.

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

The secret to a good holiday cracker joke is not the same as a good gag per se. It is all about the setting - in this instance, the shared laughter of the Christmas meal with grandparents, kids and potentially neighbours.

"You want the gag to be something that brings the eight-year-old in harmony with the 80-year-old," she adds.

The Neuroscience Of Communal Amusement

Coming together to enjoy shared laughter is not only ancient, scientists say, it is probably to be older than humanity.

"So when you are laughing with others around the holiday table you are engaging in what's very likely a really primordial mammal play sound," explains a neuroscience expert.

Shared laughter, she says, helps forge and strengthen social connections between individuals.

Researchers have found that a lack of these interactions can significantly harm both psychological and bodily well-being.

"The people you talk to, and share laughter with, it leads to enhanced amounts of 'happy chemical' uptake," she continues.

Endorphins are the body's "feel-good compounds" and are released both to reduce stress and pain and in reaction to enjoyable activities, such as laughing with loved ones over a particularly terrible Christmas cracker gag.

"You're not just chuckling at a silly joke with a holiday cracker," she says. "You are actually performing a lot of the truly important task of making, maintaining the connections you have with those you love."

Which Occurs Inside the Mind?

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

An awful lot happens in response to comedy, it transpires.

Employing functional magnetic resonance imaging (fMRI), a type of brain scanner which indicates which parts of the brain are working harder, scientists have been able to chart the areas that receive more blood flow.

Testing entails scanning the brains of healthy participants and then subjecting them to a collection of funny phrases, paired with either a neutral sound, or recorded chuckles.

"In the scanner we got a very fascinating activation pattern of activation," notes the neuroscientist.

A gag activates not just the areas of the mind in charge of auditory processing and interpreting speech, but also neural areas associated with both preparation and initiating movement and those involved in vision and memory.

Combine these elements as a whole, and individuals hearing a pun have a sophisticated set of neural reactions that support the laughter we hear.

The Infectious Nature of Laughter

Scientists found that when a funny phrase is paired with chuckles there is a stronger reaction in the mind than the identical phrase when followed by a non-emotional sound.

"This was in parts of the mind that you would use to contort your face into a grin or a chuckle," she says.

It means people are not just reacting to humorous words, they are reacting to the laughter that follows them.

Laughter, says the expert, can be infectious.

So what does this imply for the chuckles found around a holiday gathering?

"You laugh harder when you are familiar with people," she notes, "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 factor 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 joke, and it's just a reason to chuckle together."

The Search for the Ideal Cracker Joke

Is it possible to find the ultimate joke?

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

In 2001, a professor set up a research search for the planet's funniest gag.

Over tens of thousands of gags later, with scores provided by 350,000 people globally, he has a better idea than many as to what succeeds and what fails.

The perfect festive cracker joke needs to be brief, he says.

"But they also need to be poor gags, puns that cause us to groan," he continues.

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

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

"What's interesting about the Christmas cracker jokes is that not one person find them humorous.

"It creates a common experience at the table and I believe it's wonderful."