🔗 Share this article

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

This one-liner is greeted with groans that echo through a warehouse in London.

This describes a joke-testing meeting with a company that produces products for gatherings. Its catalogue features festive crackers.

The company's owner grins, nearly sheepishly at the joke. But the pun has made the cut and will appear 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 explains.

The secret to a good Christmas cracker joke is not the identical as a good joke per se. It is entirely about the setting - in this case, the communal laughter of the Christmas dinner table with elders, kids and potentially friends.

"You want the joke to be a thing that unites the eight-year-old in harmony with the grandparent," she adds.

The Science Of Communal Laughter

Coming together to experience shared laughter is not only nothing new, scientists say, it is likely to be pre-human.

"Therefore when you are chuckling with people around the holiday dinner you are engaging in what's almost certainly a truly ancient mammalian play sound," says a professor.

Shared amusement, she explains, helps make and maintain social bonds between individuals.

Researchers have discovered that a lack of these interactions can significantly harm both psychological and bodily health.

"The people you converse with, and laugh with, it leads to increased amounts of endorphin uptake," the professor continues.

These natural chemicals are the body's "feel-good compounds" and are released both to alleviate stress and pain and in reaction to pleasurable activities, such as chuckling with friends over a truly awful Christmas cracker gag.

"You're not just chuckling at a silly joke with a Christmas cracker," the expert states. "You are in fact performing a lot of the really vital task of building, preserving the social bonds you have with those you care about."

Which Occurs In the Mind?

But what is truly taking place inside the brain when we listen to a gag?

An awful lot happens in response to comedy, it turns out.

Using brain scanning technology, a kind of brain scanner which indicates which parts of the mind are working harder, scientists have been able to chart the regions that get more blood flow.

Testing entails imaging the brains of volunteer participants and then subjecting them to a database of funny phrases, paired with either a non-emotional sound, or pre-recorded laughter.

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

A joke stimulates not just the areas of the mind responsible for auditory processing and interpreting language, but also neural areas involved in both planning and initiating movement and those involved in vision and memory.

Put all of this together, and people hearing a joke have a complex series of brain responses that underpin the amusement we experience.

The Contagious Power of Laughter

Scientists found that when a funny phrase is paired with chuckles there is a greater reaction in the brain than the same phrase when accompanied by a neutral sound.

"This activation occurred in areas of the mind that you would use to contort your face into a grin or a laugh," the professor explains.

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

Amusement, says the expert, can be infectious.

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

"People laugh more when you know people," she says, "and you laugh further when you like them or love them."

When it comes to Christmas cracker jokes, she says, the feel-good factor is more likely to be caused not by the joke in itself, but from the reaction to it.

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

The Search for the Ideal Cracker Joke

Will we ever find the ultimate gag?

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

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

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

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

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

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

"The reason is that if no-one finds it funny – it's the joke's fault, not yours.

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

"It creates a common moment around the table and I think it's lovely."