How Do Festive Cracker Gags Affect Our Brains?

"How much did Santa's sled cost? Nothing, it was on the house."

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

This describes a humor-evaluation session with a company that makes supplies for gatherings. Its catalogue includes festive crackers.

The company's owner grins, almost sheepishly at the gag. But the pun has been selected and will feature in future crackers.

"The success is gauged by the gag by the number of groans and the loudness of the groans at the table," she says.

The secret to a great holiday cracker pun is not the same as a stand-up gag in itself. It is entirely about the setting - in this case, the shared laughter of the holiday meal with grandparents, children and potentially friends.

"The goal is for the joke to be a thing that brings the child together with the 80-year-old," she states.

The Science Of Shared Laughter

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

"So when you are laughing with people around the holiday table you are dropping into what's very likely a really primordial mammalian social sound," says a professor.

Communal amusement, she explains, helps forge and strengthen social bonds between individuals.

Researchers have discovered that a absence of such interactions can seriously damage both psychological and bodily well-being.

"Those you talk to, and laugh with, it results in enhanced amounts of endorphin release," the professor continues.

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

"It's not simply laughing at a silly joke with a holiday cracker," she says. "You are actually doing a lot of the truly important work of building, preserving the connections you have with the people you love."

Which Happens In the Brain?

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

A tremendous amount happens in response to comedy, it turns out.

Using functional magnetic resonance imaging (fMRI), a type of brain scanner which indicates which areas of the brain are more active, scientists have been able to chart the regions that get more blood.

The research entails scanning the minds of healthy subjects and then exposing them to a database of humorous phrases, accompanied by either a non-emotional sound, or pre-recorded chuckles.

"During the study we got a really fascinating pattern of activation," says the professor.

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

Put all of this together, and people listening to a joke have a complex set of brain reactions that underpin the laughter we hear.

The Infectious Nature of Chuckles

Researchers discovered that when a humorous word is paired with laughter there is a stronger reaction in the brain than the identical word when accompanied by a non-emotional sound.

"This activation occurred in parts of the mind that you would use to contort your face into a smile or a chuckle," the professor explains.

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

Laughter, says the professor, can be infectious.

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

"You laugh harder when you know others," she notes, "and you laugh more when you are fond of them or care for them."

When it comes to Christmas cracker jokes, she says, 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 reason to chuckle together."

The Quest for the Perfect Festive Pun

Will we ever discover the ultimate joke?

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

In 2001, a psychologist set up a scientific search for the world's funniest gag.

More than tens of thousands of gags later, with scores provided by hundreds of thousands of people around the world, he has a better idea than most as to what works and what does not.

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

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

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

"This is because if nobody finds it funny – it's the joke's shortcoming, not yours.

"What's interesting about the holiday cracker puns is that none of us find them funny.

"It creates a shared moment at the table and I think it's lovely."