A horse goes into a bar. The barman says: "Why the long face?".
Cue, maybe a smirk. It's not the funniest joke in the world, but if it raised a chuckle it probably did some good.
There's any amount of research indicating that a good laugh can do anything from increasing the melatonin in mothers' breastmilk (and thereby reducing allergic reactions in their offspring) to reducing inflammation and aiding fertility.
Conventional wisdom, of course, has it that you can't beat a good laugh.
But don't bother waiting for the punchline, say a couple of Christchurch women who are heading to Dunedin to spread the gospel of giggle.
Still, it is laughter that she plans to export next week, in the form of a workshop on laughter yoga, with a view to setting up a second laughter club in Dunedin.
Not surprisingly, for someone from Christchurch, Ms Airey emphasises the contribution laughter can make as an antidote to stress. It fires up the good chemicals - endorphins and seratonin - to keep the body's stress hormones, cortisol and adrenaline, at bay.
"Laughter is the exact opposite from stress," Ms Airey says. "It is the body's natural antidote to stress. When you are stressed the oxygen intake is lowered, your muscles are contracted, you shallow-breathe, endorphins and seratonin, well there's none of that happening when you are stressed, but cortisol and adrenaline hormones go through the roof. When you laugh, you are flooding your body and brain with oxygen, your muscles are relaxed, you deep-breathe from the diaphragm, which is really important for stress, and endorphins and serotonin are released."
Ms Airey and her hooting co-host Honalee Hunter hopped on the titter train back in 2007, after training with Dr Madan Kataria, the founder of laughter yoga. His innovation was to incorporate "the ancient science of yogic breathing into laughter exercises", according to Ms Airey.
Shortly after they set up the South Island's first laughter club in Christchurch and have since been encouraging people to set them up elsewhere around the country.
So bring on the Eddie Izzard DVD? No, actually. Ms Airey's approach cuts out the middleman.
"We tend to wait for an opportunity to laugh, we tend to wait for an external force, if you like, to make us laugh, whether it's a joke or someone does something funny. And [laughter yoga] is really about generating laughter within, and laughing for no reason at all. And it's just so powerful and so simple and we don't really laugh enough for no reason, we always wait."
The trick, she says, is to develop laughter as a conditioned response to moments of stress, build new neural pathways - laugh it off.
Laughter yoga helps do that, she says.
"Your body will just go: I'm ready to laugh now."
The way it works is that those gathered for the laughter yoga sessions just start laughing - ha, ha, ha - using laughter exercises that stimulate laughter.
"Before you know it, it is a domino effect - laughter is contagious, it is infectious - and there is natural belly-laughter happening."
Even if you are faking, you body doesn't know it, so it gets the same health benefits, she says.
Ms Airey is cautious when asked if there is something in the Kiwi make-up that means we don't laugh often enough, but she does point out that children laugh up to 400 times a day, while adults might be lucky to chuckle on 15 occasions.
"So everyone, as we grow older, we are told that our laugh sounds funny, or to stop laughing as it is not the right time to laugh, or 'You are being silly'. At work if you are laughing you are not considered to be actually working. So it is interesting, our laughs get squashed. I have noticed in doing this I am a lot more playful, I have a lot more fun with my children for sure, I don't take myself as seriously.
"This is about being able to tap into what we have, without having to get anything else externally, so that it is as natural as breathing, so you can bring it up from inside."
We all have moments when a little laughter can defuse a potentially stressful situation, she says.
"I have done this many a time: you are driving, you are running late, someone cuts in front of you, you can see some road rage starting to come up and then you just start doing some laughter. Just 'Ha, ha, ha, ha, ha, ha'. People might think you are crazy, but we have hands-free phones these days so they do not know what you are doing inside your car."
Similarly, if she realises she hasn't laughed in a while she'll set herself a task - 10 minutes of laughing - and start with a quiet recitation of "Ha, ha, ha". Eventually the absurdity of the moment turns it into the real McCoy.
But 10 minutes of laughing? Exhausting surely?
"No, not really," she insists. "If you can laugh for 10 minutes the physiological and psychological benefits are huge on the body and the brain." She sounds really quite serious about that.
Ms Airey says she was always a fairly optimistic person, someone ready to share a laugh, but at the point at which she encountered laughter yoga she was in a bit of a trough.
"I was actually going through a separation with the father of my two kids and I was going through a really, really, really bad patch and this helped. I was actually on antidepressants, I had a breakdown, and within seven months of doing the laughter yoga I was off the antidepressants."
Nothing funny about that then. Maybe there's something in this laughter.
FACT FILE
• There are 10,000 laughter clubs in 65 countries
• Laughter yoga practitioners Hannah Airey and Honalee Hunter have trained 55 people in New Zealand in the past 24 months.
• Tauranga has a club, there are two in Nelson and one in Motueka, Auckland has several, but perhaps tellingly, none of the people who trained in Wellington have gone on to start a club.
The workshop:
• Laughter yoga practitioners Hannah Airey and Honalee Hunter will be in Dunedin on September 17 and 18 to run their laughter workshop.
• The workshop will train those attending to open a community laughter club - though it is also open to those who just want to get in touch with their inner mirth (cost $260 and students $200).
• There is also a public seminar on Friday September 16, 7pm to 8.30pm for those who are a little curious ($15).