The Impact of Festive Cracker Gags Do to Our Brains?

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

This quip is met by groans that echo through a warehouse in London.

We're at a humor-evaluation meeting with a firm that produces supplies for social events. Its repertoire includes Christmas crackers.

The firm's owner smiles, nearly apologetically at the gag. But the pun has been selected and will appear in future crackers.

"You measure the joke by the number of moans and the loudness of the groans at the table," she says.

The secret to a great holiday cracker pun is not the same as a stand-up joke in itself. It is all about the context - in this instance, the shared laughter of the holiday meal with grandparents, children 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 Communal Amusement

Coming together to experience shared laughter is not only nothing new, experts say, it is likely to be older than humanity.

"Therefore when you are laughing with others at the holiday dinner you are dropping into what's almost certainly a really ancient mammal play vocalisation," says a neuroscience expert.

Communal laughter, she says, helps forge and strengthen social connections between people.

Researchers have discovered that a absence of such interactions can significantly damage mental and physical well-being.

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

Endorphins are the body's "feel-good compounds" and are produced both to alleviate tension and discomfort and in reaction to enjoyable activities, such as chuckling with friends over a truly awful festive cracker gag.

"It's not simply laughing at a foolish pun with a holiday cracker," she states. "You are in fact performing a lot of the really important work of making, maintaining the connections you have with the people you love."

What Happens In the Brain?

But what is actually happening inside the brain when we listen to a joke?

An awful lot happens in reaction to humour, it turns out.

Using functional magnetic resonance imaging (fMRI), a kind of neural imager which shows which parts of the brain are working harder, researchers have been able to map the areas that receive more blood flow.

The research entails imaging the brains of healthy subjects and then exposing them to a database of humorous words, accompanied by either a non-emotional sound, or recorded laughter.

"In the scanner we got a really interesting activation pattern of activation," says the professor.

A joke activates not just the parts of the brain responsible for hearing and interpreting language, but also brain areas associated with both preparation and initiating motion and those involved in sight and memory.

Combine all of this as a whole, and people hearing a pun have a complex series of neural responses that underpin the amusement we hear.

The Infectious Power of Chuckles

Scientists found that when a funny word is paired with chuckles there is a greater response in the brain than the same word when accompanied by a neutral sound.

"This activation occurred in areas of the mind that you would employ to move your expression into a grin or a laugh," she says.

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

Laughter, according to the professor, can be infectious.

So what does this imply for the laughter found around a holiday gathering?

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

When it comes to Christmas cracker puns, she says, the positive effect is more likely to be triggered not by the joke itself, but from the response to it.

"It's the laughter. The gag is the dreadful Christmas cracker pun, and it's just a reason to chuckle as a group."

The Quest for the Ideal Cracker Joke

Is it possible to discover the ultimate joke?

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

In 2001, a psychologist set up a research project for the planet's most humorous gag.

More than tens of thousands of gags later, with scores lodged by 350,000 participants around the world, he has a clearer idea than most as to what succeeds and what does not.

The ideal festive cracker joke must be short, he says.

"They must also be bad gags, puns that make us groan," he continues.

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

"The reason is that if no-one laughs – it's the gag's fault, not yours.

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

"It creates a shared experience around the table and I think it's lovely."