🔗 Share this article

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

This quip is met by moans that resonate through a warehouse in London.

This describes a humor-evaluation session with a firm that produces supplies for gatherings. Its catalogue includes Christmas crackers.

The company's founder smiles, almost apologetically at the gag. But the joke has made the cut and will appear in upcoming crackers.

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

The secret to a great Christmas cracker joke is not the identical as a stand-up joke per se. It is all about the context - in this case, the communal amusement of the Christmas meal with grandparents, kids and potentially neighbours.

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

The Neuroscience Of Shared Laughter

Gathering to experience communal laughter is not only ancient, scientists argue, it is probably to be pre-human.

"Therefore when you are laughing with people around the Christmas dinner you are dropping into what's almost certainly a truly primordial mammal social sound," explains a neuroscience expert.

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

Scientists have found that a absence of such social exchanges can seriously damage mental and physical health.

"The people you talk to, and laugh with, it leads to increased levels of endorphin release," she continues.

These natural chemicals are the body's "feel-good compounds" and are produced both to alleviate stress and pain and in response to pleasurable activities, such as chuckling with loved ones over a truly awful Christmas cracker joke.

"You're not just laughing at a silly joke with a Christmas cracker," she states. "You are actually performing a lot of the really vital task of making, maintaining the social bonds you have with those you care about."

What Happens Inside the Mind?

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

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

Using brain scanning technology, a kind of brain scanner which shows which areas of the mind are more active, scientists have been able to chart the areas that get more blood.

Testing involves scanning the brains of healthy subjects and then exposing them to a collection of humorous phrases, accompanied by either a neutral sound, or pre-recorded laughter.

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

A gag activates not just the parts of the brain in charge of hearing and interpreting language, but also neural areas associated with both preparation and initiating movement and those linked to vision and recall.

Put all of this together, and people listening to a joke have a sophisticated set of neural responses that underpin the amusement we experience.

The Contagious Nature of Laughter

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

"This was in parts of the brain that you would use to contort your face into a smile or a laugh," she explains.

It means we are not just reacting to humorous words, they are reacting to the laughter that accompanies them.

Amusement, says the expert, can be infectious.

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

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

When it comes to festive cracker puns, she explains, the positive effect 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 dreadful holiday cracker pun, and it's just a pretext to chuckle together."

The Quest for the Ideal Festive Pun

Is it possible to discover the perfect joke?

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

Years ago, a psychologist established a scientific project for the planet's most humorous joke.

Over 40,000 gags later, with scores lodged by hundreds of thousands of participants globally, he has a clearer understanding than many as to what works and what fails.

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

"But they also be poor gags, puns that make us groan," he adds.

The increasingly "awful" 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 puns is that none of us considers them humorous.

"It creates a shared moment around the gathering and I believe it's wonderful."