How Do Holiday Cracker Jokes Affect The Brain?

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

This quip is greeted with groans that echo through a warehouse in London.

This describes a humor-evaluation meeting with a company that produces supplies for gatherings. Its catalogue includes festive crackers.

The company's owner grins, almost sheepishly at the joke. But the pun has been selected and will feature in upcoming crackers.

"You measure the joke by the volume of moans and the loudness of the groans at the table," the founder explains.

The secret to a great Christmas cracker joke is not the same as a good gag in itself. It is all about the context - in this instance, the shared amusement of the holiday meal with elders, children and potentially friends.

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

The Science Of Shared Amusement

Coming together to enjoy shared laughter is not only ancient, scientists say, it is likely to be older than humanity.

"Therefore when you are chuckling with people at the Christmas dinner you are engaging in what's almost certainly a really primordial mammalian play vocalisation," explains a neuroscience expert.

Shared amusement, she says, aids in forge and strengthen social connections between individuals.

Scientists have found that a absence of these social exchanges can significantly harm both psychological and bodily well-being.

"Those you converse with, and laugh with, it leads to enhanced amounts of 'happy chemical' uptake," the professor continues.

These natural chemicals are the brain's "happy chemicals" and are produced both to reduce tension and discomfort and in reaction to pleasurable experiences, such as laughing with loved ones over a particularly terrible Christmas cracker gag.

"You're not just laughing at a silly pun with a holiday cracker," she states. "You are in fact doing a lot of the truly important work of making, maintaining the social bonds you have with the people you care about."

Which Happens Inside the Brain?

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

An awful lot happens in reaction to comedy, it transpires.

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

Testing involves scanning the brains of healthy subjects and then exposing them to a collection of humorous words, paired with either a non-emotional sound, or recorded laughter.

"In the scanner we observed a very interesting pattern of activation," says the professor.

A joke stimulates not just the parts of the brain in charge of auditory processing and understanding speech, but also neural regions associated with both preparation and initiating motion and those involved in sight and memory.

Put these elements together, and individuals listening to a joke have a complex set of neural reactions that underpin the laughter we hear.

The Infectious Power of Laughter

Scientists discovered that when a funny phrase is combined with laughter there is a greater reaction in the brain than the identical phrase when accompanied by a neutral sound.

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

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

Laughter, says the expert, can be contagious.

So what does this mean for the laughter found at a Christmas gathering?

"People laugh harder when you are familiar with people," she says, "and laughter increases more when you like them or love them."

When it comes to festive cracker jokes, she says, the feel-good effect is more probable to be triggered not by the joke itself, but from the reaction to it.

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

The Quest for the Ideal Festive Pun

Will we ever discover the ultimate gag?

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

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

Over 40,000 gags later, 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 fails.

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

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

The more "awful" the joke, he states the better.

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

"The fascinating part about the Christmas cracker jokes is that not one person find them funny.

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