How Do Holiday Cracker Jokes Do to The Brain?

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

This one-liner is met by moans that echo through a storage facility in London.

We're at a joke-testing meeting with a company that makes supplies for gatherings. Its catalogue features festive crackers.

The company's founder grins, almost sheepishly at the joke. But the joke has made the cut and will feature in upcoming crackers.

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

The secret to a good Christmas cracker joke is not the identical as a stand-up gag in itself. It is entirely about the setting - in this case, the communal laughter of the holiday meal with elders, kids and potentially friends.

"The goal is for the gag to be a thing that brings the eight-year-old in harmony with the 80-year-old," she states.

The Neuroscience Of Communal Laughter

Coming together to experience communal laughter is not only nothing new, experts argue, it is probably to be older than humanity.

"So when you are laughing with people around the Christmas table you are dropping into what's almost certainly a truly primordial mammal social vocalisation," explains a professor.

Shared amusement, she explains, helps forge and strengthen social connections between people.

Scientists have found that a absence of these interactions can significantly damage both psychological and bodily health.

"Those you talk to, and share laughter with, it leads to enhanced amounts of endorphin uptake," she continues.

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

"It's not simply laughing at a foolish joke with a holiday cracker," the expert says. "You are actually doing a lot of the really important task of making, maintaining the social bonds you have with those you love."

What Happens In the Mind?

But what is actually taking place inside the mind when we hear a joke?

An awful lot occurs in reaction to comedy, it transpires.

Employing functional magnetic resonance imaging (fMRI), a type of brain scanner which indicates which parts of the mind are working harder, scientists have been able to map the regions that get more blood.

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

"During the study we observed a really interesting pattern of neural activity," says the professor.

A gag stimulates not just the areas of the mind in charge of hearing and understanding speech, but also neural areas involved in both preparation and starting movement and those linked to sight and memory.

Put all of this as a whole, and people listening to a pun have a complex series of neural reactions that underpin the amusement we experience.

The Contagious Nature of Laughter

Scientists found that when a humorous word is paired with chuckles there is a stronger reaction in the brain than the same phrase when accompanied by a non-emotional sound.

"This was in parts of the brain that you would employ to contort your face into a grin or a chuckle," she explains.

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

Amusement, says the professor, can be infectious.

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

"You laugh harder when you are familiar with others," she notes, "and you laugh more when you are fond of them or love them."

When it comes to Christmas cracker jokes, she explains, the positive factor is more likely to be triggered not by the gag itself, but from the response to it.

"The laughter is key. The joke is the terrible holiday cracker joke, and it's just a reason to chuckle as a group."

The Quest for the Perfect Cracker Joke

Is it possible to find the perfect joke?

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

Years ago, a psychologist established a scientific search for the planet's funniest joke.

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

The perfect festive cracker pun needs to be short, he says.

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

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

"This is because if no-one finds it funny – it's the gag's fault, not your own.

"The fascinating part about the holiday cracker jokes is that not one person considers them humorous.

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