What Do Christmas Cracker Puns Affect The Brain?

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

This quip is greeted with moans that echo through a warehouse in the capital.

We're at a humor-evaluation session with a firm that makes products for gatherings. Its catalogue includes Christmas crackers.

The company's owner smiles, nearly sheepishly at the gag. But the joke has been selected and will appear in future crackers.

"The success is gauged by the gag by the number of groans and the intensity of the groans at the table," the founder explains.

The secret to a good Christmas cracker pun is not the same as a good gag per se. It is all about the setting - in this instance, the communal laughter of the holiday meal with grandparents, kids and possibly friends.

"You want the joke to be a thing that brings the eight-year-old in harmony with the 80-year-old," she adds.

The Science Of Communal Laughter

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

"So when you are laughing with others at the holiday table you are engaging in what's almost certainly a really primordial mammal play vocalisation," says a professor.

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

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

"Those you converse with, and share laughter with, it results in enhanced levels of 'happy chemical' release," the professor adds.

Endorphins are the brain's "feel-good compounds" and are produced both to alleviate tension and discomfort and in response to enjoyable experiences, such as laughing with loved ones over a particularly terrible festive cracker joke.

"You're not just chuckling at a silly joke with a Christmas cracker," she says. "You are actually doing a lot of the truly important work of making, maintaining the connections you have with the people you love."

What Occurs Inside the Brain?

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

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

Using brain scanning technology, a kind of brain scanner which shows which parts of the brain are working harder, researchers have been able to map the areas that get more blood flow.

The research involves scanning the minds of healthy subjects and then subjecting them to a database of funny phrases, paired with either a non-emotional sound, or recorded chuckles.

"During the study we got a very fascinating activation pattern of neural activity," notes the professor.

A gag stimulates not just the areas of the brain in charge of hearing and understanding language, but also brain regions involved in both preparation and initiating motion and those involved in sight and recall.

Put these elements as a whole, and individuals listening to a joke have a sophisticated series of neural responses that support the laughter we experience.

The Contagious Power of Chuckles

Scientists discovered that when a humorous word is combined with chuckles there is a stronger reaction in the mind than the identical word when accompanied by a neutral sound.

"This was in areas of the brain that you would use to move your expression into a smile or a laugh," the professor says.

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

Amusement, says the professor, can be infectious.

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

"People laugh harder when you know others," she notes, "and you laugh more when you like them or care for them."

When it comes to Christmas cracker puns, she says, the feel-good effect is more probable to be caused not by the joke itself, but from the response to it.

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

The Search for the Ideal Cracker Joke

Will we ever find the ultimate joke?

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

Years ago, a psychologist set up a scientific search for the planet's funniest gag.

Over 40,000 gags later, with scores provided by 350,000 people around the world, he has a better understanding than most as to what works and what fails.

The perfect festive cracker joke must be brief, he explains.

"They must also be poor jokes, puns that make us groan," he adds.

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

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

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

"It creates a common moment around the gathering and I believe it's lovely."