How Do Christmas Cracker Jokes Do to The Brain?

"What was the price did Santa's sled cost? Zero, it was on the house."

This joke is met by groans that resonate through a storage facility in the capital.

This describes a humor-evaluation session with a company that produces products for social events. Its repertoire features festive crackers.

The firm's founder grins, nearly sheepishly at the gag. But the joke has made the cut and will feature in future crackers.

"The success is gauged by the joke by the number of moans and the loudness of the groans around the table," she explains.

The key to a great Christmas cracker joke is not the same as a stand-up gag in itself. It is all about the setting - in this case, the communal amusement of the Christmas meal with grandparents, children and possibly friends.

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

The Neuroscience Of Shared Laughter

Coming together to experience communal laughter is not only nothing new, experts argue, it is likely to be pre-human.

"Therefore when you are chuckling with others around the holiday table you are dropping into what's very likely a really ancient mammal social sound," explains a neuroscience expert.

Communal amusement, she explains, helps forge and strengthen social connections between people.

Researchers have found that a absence of these interactions can seriously damage mental and physical well-being.

"The people you talk to, and share laughter with, it leads to increased levels of endorphin uptake," she continues.

These natural chemicals are the body's "happy chemicals" and are released both to alleviate tension and discomfort and in reaction to enjoyable experiences, such as laughing with loved ones over a particularly awful festive cracker gag.

"You're not just chuckling at a foolish pun with a holiday cracker," she says. "You are in fact doing a lot of the really important task of building, preserving the social bonds you have with those you care about."

Which Happens In the Mind?

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

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

Using brain scanning technology, a type of brain scanner which indicates which parts of the brain are more active, researchers have been able to chart the areas that receive more blood flow.

The research entails imaging the minds of volunteer participants and then subjecting them to a database of humorous words, paired with either a non-emotional sound, or pre-recorded laughter.

"During the study we got a really interesting activation pattern of neural activity," says the neuroscientist.

A joke stimulates not just the areas of the mind in charge of hearing and interpreting language, but also neural regions associated with both preparation and initiating movement and those involved in vision and memory.

Combine all of this together, and people hearing a joke have a sophisticated set of neural reactions that underpin the laughter we experience.

The Infectious Power of Laughter

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

"This was in areas of the brain that you would use to move your face into a smile or a chuckle," she explains.

It means people are not just responding to humorous jokes, they are responding to the amusement that accompanies them.

Laughter, according to the professor, can be infectious.

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

"You laugh more when you are familiar with others," she notes, "and laughter increases more when you are fond of them or love them."

When it comes to Christmas cracker puns, she explains, the positive factor is more likely to be triggered not by the gag in itself, but from the response to it.

"The laughter is key. The gag is the terrible holiday cracker pun, and it's just a pretext to chuckle together."

The Search for the Perfect Festive Pun

Will we ever find the ultimate gag?

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

In 2001, a professor established a research search for the planet's funniest joke.

Over tens of thousands of gags later, with scores lodged by 350,000 people globally, he has a better idea than many as to what succeeds and what does not.

The perfect Christmas cracker pun must be brief, he explains.

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

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

"This is because if no-one finds it funny – it's the gag's shortcoming, not yours.

"What's interesting about the holiday cracker puns is that none of us find them humorous.

"It creates a shared moment at the table and I believe it's wonderful."