🔗 Share this article

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

This joke is greeted with groans that resonate through a warehouse in London.

We're at a humor-evaluation session with a firm that produces supplies for gatherings. Its repertoire includes Christmas crackers.

The firm's owner grins, nearly apologetically at the gag. But the pun has made the cut and will appear in upcoming crackers.

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

The secret to a good holiday cracker joke is not the same as a stand-up gag per se. It is entirely about the setting - in this instance, the shared amusement of the Christmas dinner table with grandparents, children and potentially neighbours.

"You want the joke to be something that unites the eight-year-old together with the grandparent," she adds.

The Science Behind Shared Laughter

Gathering to enjoy communal amusement is not only ancient, scientists argue, it is probably to be older than humanity.

"So when you are chuckling with people around the holiday dinner you are engaging in what's almost certainly a truly primordial mammalian social sound," says a neuroscience expert.

Shared amusement, she explains, aids in make and maintain social connections between individuals.

Scientists have discovered that a absence of such interactions can seriously damage mental and physical health.

"Those you talk to, and share laughter with, it results in enhanced levels of 'happy chemical' uptake," she adds.

Endorphins are the brain's "happy chemicals" and are produced both to alleviate tension and discomfort and in reaction to enjoyable experiences, such as laughing with friends over a truly terrible Christmas cracker gag.

"It's not simply laughing at a foolish joke with a holiday cracker," she says. "You are in fact performing a lot of the really important work of building, preserving the connections you have with those you care about."

Which Occurs In the Brain?

But what is truly happening within the mind when we hear a gag?

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

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

Testing involves imaging the minds of volunteer participants and then subjecting them to a collection of humorous words, accompanied by either a neutral sound, or pre-recorded laughter.

"During the study we observed a very interesting activation pattern of activation," notes the neuroscientist.

A joke stimulates not just the parts of the mind in charge of hearing and understanding language, but also neural areas associated with both preparation and initiating motion and those involved in sight and memory.

Put these elements as a whole, and people hearing a pun have a complex set of neural reactions that underpin the amusement we experience.

The Infectious Power of Laughter

Scientists discovered that when a funny phrase is paired with chuckles there is a stronger reaction in the brain than the identical word when followed by a non-emotional sound.

"This was in areas of the mind that you would use to contort your expression into a grin or a laugh," the professor says.

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

Laughter, according to the professor, can be infectious.

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

"People laugh harder when you are familiar with people," she notes, "and you laugh further when you are fond of them or care for them."

When it comes to Christmas cracker jokes, she says, the positive effect is more probable to be caused not by the gag itself, but from the reaction to it.

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

The Search for the Ideal Festive Pun

Is it possible to find the ultimate gag?

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

Years ago, a professor established a scientific search for the planet's funniest gag.

Over 40,000 jokes submitted, with ratings lodged by hundreds of thousands of participants around the world, he has a better idea than most as to what succeeds and what does not.

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

"But they also need to be bad gags, jokes that cause us to groan," he continues.

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

"This is because if no-one laughs – it's the joke's fault, not yours.

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

"That's a shared moment around the table and I think it's lovely."