How Do Festive Cracker Gags Affect Our Brains?

"How much 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 firm that produces products for gatherings. Its catalogue features festive crackers.

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

"You measure the gag by the number of groans and the intensity of the groans at the table," the founder explains.

The secret to a great holiday cracker pun is not the identical as a good joke per se. It is all about the setting - in this instance, the communal amusement of the Christmas dinner table with elders, children and potentially neighbours.

"You want the joke to be a thing that brings the eight-year-old together with the 80-year-old," she adds.

The Neuroscience Of Communal Amusement

Coming together to experience shared laughter is not only nothing new, experts say, it is likely to be older than humanity.

"Therefore when you are chuckling with others at the Christmas table you are dropping into what's very likely a really ancient mammalian social vocalisation," says a neuroscience expert.

Shared amusement, she says, aids in forge and strengthen social connections between individuals.

Researchers have found that a absence of such interactions can seriously damage mental and physical health.

"Those you converse with, and share laughter with, it results in enhanced levels of endorphin uptake," she adds.

Endorphins are the brain's "feel-good compounds" and are produced both to reduce stress and pain and in response to pleasurable activities, such as laughing with friends over a particularly awful festive cracker gag.

"You're not just chuckling at a silly joke with a Christmas cracker," she says. "You are actually performing a lot of the truly important work of making, maintaining the social bonds you have with the people you love."

What Happens Inside the Mind?

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

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

Using 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 receive more blood.

The research entails imaging the brains of volunteer subjects and then subjecting them to a collection of funny phrases, paired with either a non-emotional sound, or pre-recorded chuckles.

"In the scanner we observed a very fascinating activation pattern of neural activity," says the neuroscientist.

A gag activates not just the parts of the mind in charge of hearing and interpreting speech, but also neural regions involved in both preparation and initiating motion and those involved in sight and recall.

Combine these elements together, and people hearing a joke have a complex set of neural reactions that underpin the laughter we experience.

The Infectious Nature of Chuckles

Researchers found that when a funny phrase is combined with chuckles there is a stronger response in the brain than the identical word when accompanied by a neutral sound.

"This activation occurred in parts of the mind that you would employ to contort your face into a smile or a chuckle," she says.

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

Amusement, according to the professor, can be infectious.

So what does this mean for the laughter heard at a holiday table?

"You laugh harder when you are familiar with people," she notes, "and you laugh further when you like them or love them."

When it comes to Christmas cracker puns, she says, the feel-good factor is more probable to be triggered not by the gag in itself, but from the reaction to it.

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

The Search for the Ideal Cracker Joke

Is it possible to discover the perfect joke?

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

Years ago, a professor set up a research project for the world's most humorous joke.

More than 40,000 gags submitted, with ratings lodged by 350,000 people around the world, he has a clearer understanding than many as to what works and what fails.

The ideal Christmas cracker joke needs to be short, he says.

"They must also be poor jokes, jokes that make us moan," he adds.

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

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

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

"That's a common moment at the gathering and I believe it's wonderful."