How Do Christmas Cracker Puns Do to The Brain?

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

This quip is greeted with moans that resonate through a warehouse in the capital.

We're at a humor-evaluation meeting with a company that makes products for social events. Its repertoire features festive crackers.

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

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

The secret to a great Christmas cracker pun is not the same as a stand-up gag in itself. It is all about the setting - in this instance, the communal amusement of the Christmas dinner table with elders, kids and potentially neighbours.

"You want the joke to be a thing that unites the child together with the grandparent," she states.

The Neuroscience Behind Shared Laughter

Coming together to experience communal amusement is not only nothing new, scientists say, it is probably to be older than humanity.

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

Communal amusement, she says, aids in make and maintain social bonds between individuals.

Scientists have discovered that a lack of such interactions can seriously damage mental and physical health.

"Those you talk to, and share laughter with, it results in increased amounts of 'happy chemical' release," she continues.

Endorphins are the brain's "feel-good compounds" and are released both to reduce stress and pain and in response to enjoyable experiences, such as chuckling with loved ones over a particularly terrible Christmas cracker joke.

"It's not simply chuckling at a foolish pun with a holiday cracker," she says. "You are actually doing a lot of the truly important task of building, preserving the social bonds you have with those you love."

Which Happens In the Mind?

But what is actually happening within the brain when we listen to a joke?

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

Using functional magnetic resonance imaging (fMRI), a kind of neural imager which indicates which areas of the mind are more active, researchers have been able to map the regions that get more blood.

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

"In the scanner we got a really fascinating activation pattern of activation," says the neuroscientist.

A joke stimulates not just the parts of the brain in charge of auditory processing and interpreting language, but also neural areas associated with both preparation and starting movement and those linked to vision and recall.

Put all of this as a whole, and people hearing a pun have a complex series of brain responses that underpin the laughter we hear.

The Contagious Power of Laughter

Researchers found that when a funny phrase is paired with laughter there is a stronger response in the brain than the same word when followed by a non-emotional sound.

"This activation occurred in areas of the brain that you would employ to contort your expression into a grin or a chuckle," the professor explains.

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

Laughter, according to the professor, can be infectious.

So what does this mean for the chuckles found at a holiday table?

"People laugh more when you are familiar with people," she says, "and you laugh more when you are fond of them or love them."

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

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

The Quest for the Perfect Festive Pun

Will we ever discover the perfect joke?

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

Years ago, a psychologist established a research project for the world's most humorous gag.

More than tens of thousands of jokes later, with scores lodged by 350,000 people globally, he has a better idea than most as to what works and what fails.

The ideal festive cracker pun needs to be short, he explains.

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

The more "terrible" the joke, he says the more effective.

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

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

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