THE SEVEN DEADLY GRINS; Experts name laugh types a and how they give you away.
Aberdeen University's Dr Lesley Harbidge profiled more than 1000 people for comedy channel UKTV G2. She said: 'This is the season to be jolly and it's true, we seem to laugh more in December than at other time - and the way someone laughs can give quite a lot away.'
Channel controller John Keeling said: 'I'm sure we'll all pay more attention when someone starts laughing.'
Here are the seven kinds of laughter - and their celebrity owners
A SNOOTY type who is prone to expelling short, loud bursts of air through the nostrils.
This laugh is often associated with refined ladies and pompous men as well as those aspiring to a higher social class.
The snort often indicates contempt, or disapproval from someone who feels superior to those around them.
These are snotty people who snort like pigs.
Celebrity snorter: Michael Winner.
HOPE you don't find yourself in the company of a howler.
They have an uncontrollable and hysterical laugh which is likely to frighten animals and small children.
Streaming tears and flailing limbs - suggestive of a person slightly unhinged - are part of this attention seeker's expression of mirth.
They are an embarrassment to themselves and others.
Be wary of accompanying them in public or to parties.
And if you find yourself in their vicinity at the office party... get out fast - or risk redundancy.
Celebrity Howler: Jade Goody.
SUPPRESSED laughter - a closed, nasal form constricted by closed lips - is a snigger.
This is not an attractive or desirable quality. It shows an immature, insensitive and unsympathetic character.
Ignite the kitchen when you light the Christmas pudding and the place will have burned to the ground before he thinks about calling 999. He'll be too busy revelling in your misfortune.
Celebrity Sniggerer: Graham Norton.
THESE people vent a light, silly sound characterised by short, snatches of breath and a seemingly innocent smile.
It's the most flirtatious, suggestive and sexual of laughs and is commonly exhibited in groups of young females circling crowds of men.
Celebrity Gigglers: Paul Burrell, Cameron Diaz, Babs Windsor.
MORE earthy than the snorter, belly busters are less snooty and like to let rip with a roar which comes from deep in the abdomen.
This kind of laugh goes down well on a night out.
Belly busters are open, trustworthy and full of good spirits, but beware - one can be fatal.
Thirty years ago, builder Alex Mitchell, of King's Lynn, Norfolk, died of heart failure after laughing for half an hour watching The Goodies beating a black pudding with bagpipes.
Celebrity Belly Busters: Billy Connolly, Brian Blessed.
THE Cackler is prone to shrill primate-style shrieks. Guttural grunts unrelated to known human speech also a feature.
Popping eyes, the rubbing of hands and random arm movements accompany this disturbing show.
Cacklers are often found laughing at their good fortune or the bad luck of others.
It has a special importance at Christmas - as a character trait for pantomime villains.Celebrity Cackler: Janet Street Porter, Ruby Wax.
CHIRPY, easy on the ear - a little introspective but generally kindly.
In certain conditions, this can transform into a Sid James-style dirty laugh.
Celebrity Chucklers: Joe Pasquale and Del Boy.