How Do Holiday Cracker Jokes Influence The Brain?

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

This one-liner is greeted with moans that resonate through a warehouse in the capital.

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

The firm's owner smiles, almost sheepishly at the joke. But the pun has been selected and will appear in upcoming crackers.

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

The key to a good Christmas cracker joke is not the identical as a good gag in itself. It is entirely about the context - in this case, the shared amusement of the holiday dinner table with elders, kids and possibly friends.

"You want the gag to be something that unites the eight-year-old in harmony with the grandparent," she adds.

The Science Behind Shared Amusement

Gathering to experience communal laughter is not only ancient, scientists say, it is probably to be older than humanity.

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

Communal laughter, she says, aids in forge and strengthen social connections between individuals.

Researchers have discovered that a absence of such social exchanges can significantly harm mental and physical well-being.

"Those you converse with, and laugh with, it results in increased amounts of 'happy chemical' release," she adds.

These natural chemicals are the brain's "happy chemicals" and are released both to alleviate tension and discomfort and in reaction to pleasurable experiences, such as laughing with friends over a truly terrible festive cracker gag.

"It's not simply chuckling at a foolish pun with a holiday cracker," she says. "You are in fact performing a lot of the truly vital task of building, preserving the social bonds you have with the people you love."

Which Happens Inside the Brain?

But what is truly happening inside the mind when we hear a joke?

A tremendous amount occurs in response to comedy, it turns out.

Using brain scanning technology, a kind of neural imager which indicates which parts of the mind are more active, scientists have been able to chart the regions that receive more blood flow.

The research involves scanning the minds of volunteer participants and then exposing them to a collection of funny words, accompanied by either a neutral sound, or pre-recorded laughter.

"In the scanner we got a really fascinating activation pattern of activation," notes the neuroscientist.

A joke stimulates not just the areas of the brain responsible for auditory processing and interpreting speech, but also brain regions associated with both planning and initiating motion and those linked to sight and recall.

Put all of this together, and individuals listening to a joke have a complex set of neural responses that underpin the amusement we hear.

The Infectious Power of Chuckles

Researchers found that when a humorous word is combined with laughter there is a stronger reaction in the mind than the identical word when followed by a neutral sound.

"This activation occurred in areas of the brain that you would employ to contort your expression into a grin or a laugh," the professor says.

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

Laughter, according to the expert, can be infectious.

So what does this mean for the chuckles found at a holiday table?

"You laugh more when you know people," she says, "and laughter increases further when you like them or love them."

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

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

The Quest for the Ideal Cracker Joke

Is it possible to find the ultimate joke?

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

Years ago, a professor set up a research project for the planet's most humorous joke.

Over 40,000 jokes later, with ratings lodged by 350,000 people around the world, he has a clearer understanding than many as to what works and what fails.

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

"They must also need to be bad gags, puns that make us groan," he adds.

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

"The reason is that if no-one finds it funny – it's the gag's fault, not your own.

"What's interesting about the Christmas cracker jokes is that none of us considers them humorous.

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