What Do Christmas Cracker Puns Do to Our Brains?

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

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

We're at a humor-evaluation session with a firm that makes supplies for social events. Its catalogue features festive crackers.

The firm's founder grins, nearly sheepishly 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 number of groans and the loudness of the groans at the table," the founder says.

The key to a great holiday cracker joke is not the identical as a stand-up gag in itself. It is all about the setting - in this case, the shared laughter of the holiday dinner table with elders, children and possibly friends.

"You want the gag to be something that brings the child in harmony with the 80-year-old," she adds.

The Science Behind Shared Laughter

Coming together to enjoy shared laughter is not only nothing new, scientists say, it is probably to be older than humanity.

"So when you are chuckling with others around the holiday dinner you are dropping into what's very likely a really primordial mammalian play sound," says a professor.

Shared amusement, she explains, aids in forge and strengthen social bonds between individuals.

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

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

Endorphins are the body's "happy chemicals" and are released both to alleviate stress and pain and in response to enjoyable experiences, such as laughing with loved ones over a truly terrible Christmas cracker joke.

"It's not simply chuckling at a foolish joke with a holiday cracker," the expert states. "You are actually performing a lot of the truly vital task of building, preserving the social bonds you have with the people you care about."

What Happens In the Brain?

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

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

Using brain scanning technology, a kind of neural imager which indicates which areas of the brain are working harder, scientists have been able to chart the areas that get more blood flow.

The research involves scanning the minds of healthy subjects and then exposing them to a collection of funny words, accompanied by either a neutral sound, or recorded chuckles.

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

A gag activates not just the parts of the mind in charge of auditory processing and interpreting language, but also brain areas associated with both planning and starting movement and those involved in sight and recall.

Combine these elements as a whole, and individuals hearing a pun have a complex set of brain responses that underpin the laughter we experience.

The Infectious Power of Laughter

Researchers discovered that when a funny word is paired with laughter there is a stronger reaction in the mind than the identical word when accompanied by a neutral sound.

"This was in parts of the brain that you would employ to contort your face into a smile or a chuckle," the professor explains.

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

Amusement, says the professor, can be infectious.

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

"You laugh harder when you know people," she says, "and laughter increases more when you like them or care for them."

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

"The laughter is key. The joke is the dreadful holiday cracker joke, and it's just a reason to chuckle as a group."

The Search for the Perfect Cracker Joke

Is it possible to discover the ultimate gag?

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

Years ago, a professor established a research project for the world's most humorous joke.

More than tens of thousands of jokes later, with scores lodged by 350,000 participants around the world, he has a better understanding than many as to what succeeds and what does not.

The ideal Christmas cracker joke must be short, he explains.

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

The more "terrible" the joke, he states the more effective.

"The reason is that if nobody finds it funny – it's the joke's shortcoming, not your own.

"The fascinating part about the holiday cracker puns is that none of us considers them humorous.

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