The old saying, “Laughter is the best medicine” has been proven to have some truth in it: studies demonstrate how people who can laugh at themselves and at life live longer and more happily. Laughter is aerobic and releases serotonin, which boosts your immunity, shoots pain-relieving endorphins around your bloodstream, and even counters the effects of stress.

Above all, laughter is a social phenomenon, which provides a profound connection between human beings. Shared laughter is undeniably bonding; studies have shown that people are 30 per cent more likely to laugh at the same content if they are in a social group, rather than sitting in isolation. We’ve probably all experienced how sitting down to watch a comedy together, sharing a laugh together, is a much more satisfying experience than watching it alone.

Laughter is genuinely contagious. Most people will mirror your mirth; if they see you laughing, they will naturally join in. In fact, people tend to smile when they hear laughter. It has been proposed that our human ancestors laughed before language evolved – a way of bonding in groups, which we still recognise today.

Guffaws of genuine, heartfelt amusement – sometimes called belly laughter – are the holy grail of laughter: comedians strive endlessly to elicit this response; social animals are always gratified when their anecdotes and repartee are greeted by a chorus of (laughing) approval. There are many other different types of laughter, and not all of them are welcome:

Nervous Laughter

Nervous laughter often seems to break out at times when you’re trying to demonstrate that you are dignified or authoritative. A rising, choking tide of giggles may well be the result of a subconscious attempt to reduce stress and calm down, but of course its impact is not desirable – in many contexts (eg a presentation at work, an interview, a meeting with an important client), snorts of laughter are going to be viewed with disapproval and disappointment. You will be castigated for your lack of seriousness and gravitas.

If you’re prone to nervous laughter, the first step is to be fully conscious of the occasions when your chuckling has nothing to do with amusement. Try and find substitute reactions that you can use to consciously pre-empt the laughter: a slow head nod; a head tilt; clasping your hands together. You might even find that alternative methods of relieving tension will forestall the laughter: taking deep breaths; tapping your foot; tapping your thumb and forefinger together.

Stress-Relieving Laughter

Where laughter can genuinely release stress is in instances when you, and your companions, are being put under pressure (eg a team-building exercise, a demanding meeting, a rush to complete an important task or beat a deadline) and are cooperating to complete the challenge. As soon as the task is complete and you can relax, you may well find that general hilarity is a highly effective way of dealing with the aftermath of all the tension. If you complete an arduous task or undergo an experience that you have been dreading (an operation, courtroom appearance etc), you may find yourself overwhelmed by feelings of relief and laughter will come readily.

Polite Laughter

Sometimes laughter is just good manners, not a sign of genuine amusement. If you are trying to please, or placate somebody – a demanding boss, an important guest, an awkward customer – an obvious way of disarming and flattering them is to laugh at their jokes and anecdotes, even if you don’t find them remotely funny. Genuine laughter is a way of bonding with your fellow humans; polite laughter is a good way of simulating this kind of intimacy – just make sure you don’t exaggerate the sound-effects, as artificial-sounding laughter will give the game away.

Inappropriate Laughter

Because of its stress-relieving properties, laughter can bubble up, irrepressibly, in a host of inappropriate situations. Laughing at a funeral is generally not acceptable (unless the eulogy is a comic tour de force) but laughing at the wake afterwards can be a life-affirming release. Laughing at a child’s ear-piercing first attempts to play their recorder will never endear you to their proud parents; laughing at their stories of the little one’s potty-training escapades will. It’s all about prepositions – laughing with but not at.

Cruel Laughter

A little judgement should be exercised before unleashing laughter indiscriminately. Laughing at someone else, or at someone else’s expense, will lead to trouble, so it is best to always check at what or whom your laughter is directed and remembering that laughter can also be cruel. This is especially the case if your laughter is directed at someone who is trying hard to do something they really care about (and failing), because it shows that you are dismissive of their efforts.

Annoying Laughter

As for how one laughs – the sound of laughter is not universally tinkling and infectious and can be downright grating. Ask a close friend for honest feedback on whether your laughter is charming or, frankly, frightening.

We’ve probably all been in social situations where we have been driven mad by someone who is prone to emitting deafening barks of laughter, who snorts and snuffles after every statement, or who whoops with high-pitched hysterical glee. In most cases, there is very little you can do about these maddening sound-effects.

If you are very close to a terrible laugher, whose humorous outbursts have the same effect on you (and other people – check this out first) as chalk screeching on a blackboard, you might feel compelled to raise the issue. The only way to do this is to hedge your critique about with heartfelt compliments and then say something like “You have a very loud laugh and I think some people find it a bit disconcerting” or “You laugh after everything you say, and I think it might be undermining you”. It is important to point out that the laugh might be impeding your friend’s social/professional progress, rather than getting bogged down in vivid descriptions of your own irritation. Adopt this approach with real caution, however, as many people will not react well to this sort of criticism.