🔗 Share this article

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

This one-liner is met by groans that echo through a warehouse in the capital.

We're at a joke-testing session with a firm that makes products for gatherings. Its catalogue features Christmas crackers.

The firm's owner smiles, almost sheepishly at the joke. But the pun has been selected and will feature in future crackers.

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

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

"The goal is for the joke to be something that unites the child in harmony with the 80-year-old," she adds.

The Science Of Communal Amusement

Coming together to enjoy shared amusement is not only ancient, scientists say, it is likely to be pre-human.

"Therefore when you are laughing with people at the Christmas dinner you are engaging in what's almost certainly a really primordial mammal social vocalisation," explains a neuroscience expert.

Communal laughter, she says, aids in make and maintain social connections between individuals.

Scientists have found that a absence of these social exchanges can significantly damage mental and physical well-being.

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

These natural chemicals are the body's "happy chemicals" and are released both to reduce stress and pain and in reaction to enjoyable experiences, such as laughing with friends over a truly awful festive cracker joke.

"You're not just chuckling at a silly joke with a holiday cracker," she says. "You are actually performing a lot of the really important task of building, preserving the social bonds you have with those you love."

What Happens Inside the Mind?

But what is truly taking place within the mind when we hear a joke?

An awful lot occurs in response to humour, it turns out.

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

Testing involves imaging the brains of healthy subjects and then subjecting them to a database of funny phrases, accompanied by either a non-emotional sound, or recorded chuckles.

"During the study we got a really fascinating pattern of neural activity," notes the neuroscientist.

A joke activates not just the areas of the mind responsible for auditory processing and understanding speech, but also brain areas involved in both planning and starting movement and those involved in sight and recall.

Combine these elements as a whole, and individuals hearing a joke have a sophisticated series of brain reactions that support the amusement we experience.

The Infectious Nature of Laughter

Researchers discovered that when a humorous word is combined with chuckles there is a stronger response in the brain than the same word when accompanied by a non-emotional sound.

"This activation occurred in areas of the brain that you would use to contort your expression into a smile or a laugh," she says.

It indicates people are not just responding to humorous jokes, they are reacting to the amusement that follows them.

Amusement, says the professor, can be infectious.

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

"People laugh harder when you are familiar with people," she notes, "and laughter increases more when you like them or care for them."

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

"It's the laughter. The joke is the dreadful Christmas cracker joke, and it's just a pretext to chuckle together."

The Quest for the Perfect Cracker Joke

Will we ever discover the perfect joke?

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

In 2001, a professor set up a research search for the world's funniest joke.

Over tens of thousands of jokes submitted, with scores provided by hundreds of thousands of people globally, he has a better understanding than most as to what works and what fails.

The ideal Christmas cracker pun must be brief, he says.

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

The increasingly "terrible" the joke, he says the better.

"The reason is that if nobody finds it funny – it's the joke's shortcoming, not your own.

"The fascinating part about the holiday cracker jokes is that none of us find them funny.

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