The jokes you make and what makes you laugh reveal more about you than you realise.

Heard the one about the loveless marriage? The miserable mother-in-law? Oh, you must have. Along with death and sexual inadequacies, they provide some of the most popular themes for jokes. Why? The father of psychology, Sigmund Freud, is among those to have come up with an answer to that: we use jokes to deal with our anxieties and issues.

"A cigar may just be a cigar, but a joke is never just a joke," he famously said. "Sometimes people joke about the same thing over and over and that's when our antennae should go up," agrees Sydney psychologist Susan Nicholson. An example of this might be an older person laughing at jokes about dementia and deafness.

"They might be oblivious to the fact that the subject is a source of anxiety for them," Nicholson continues, "but if cracking those jokes helps release some of that anxiety, it serves a positive function." Dr Tim Sharp, psychologist and chief happiness officer at the Happiness Institute, says there is no doubt that a sense of humour is a strength that correlates with health and happiness.

This applies particularly to those in dire straits. "Being able to hang on to a sense of humour is an incredibly positive trait," Nicholson says. "It's a fantastic coping mechanism and has a reinforcing cycle, because the more you are able to see the funny side and laugh, the greater the sense of happiness it instils, and that allows you to see even more positive things."

"Humour is a core component in resiliency," Sharp agrees. "And one reason for that is because it's about seeing things from a different perspective; something that all the best cartoonists and comedians do. "The happiest and most successful people don't just stop at one way of looking at a situation; they'll explore other ways. That's also the basis of cognitive behavioural therapy, which is very successful in treating all kinds of depression."

When jokes aren't funny

Not all humour is positive, however. Greek scholar Aristotle argued that many successful clowns and comedians make us laugh by eliciting a sense of superiority. And throughout history it's not difficult to find support for that claim. Dwarves, hunchbacks and even people in psychiatric institutions have all had fun poked at them. And while we might like to think we are more evolved, the jokes we tell today that claim that people of a certain nationality are stupid, work-shy or stingy, suggest otherwise.

Does this matter? Yes it does. A study from Cardiff University in Wales found that if people repeatedly tell jokes that portray a race as stupid, they eventually believe that to be true.

Similarly, when a German professor, Jens Forster, gave intelligence tests to two groups of women, blonde women who were given blonde jokes to read beforehand obtained lower scores than a control group of blondes who were not. This suggests that jokes have the power to affect people's confidence and behaviour.

And what of those who appear to have no sense of humour at all? There is evidence that people who have suffered brain damage, particularly to the right hemisphere of the brain, are less able to understand jokes. Other people who have all their mental faculties intact still seem to have a problem with humour. They make what they think are jokes, while remaining oblivious to the fact that no-one is laughing.

"That's generally because they're not as empathic as most people, and a bit oblivious to the intuitive and feeling sides which give us clues to the fact that people have had enough," explains Nicholson.

"It might also be that they don't give a damn that no-one else finds them funny, but that still shows a lack of sensitivity in regard to other people's responses."

Worldly humour

Lots of humour is also cultural, adds Sharp. Australian humour, for instance (according to the government's Culture and Recreation website) is "dry, full of extremes, anti-authoritarian, self-mocking and ironic". This means that Asians, who are raised to respect authority, are confused by our penchant for mocking our rulers and leaders.

Similarly, Australian and British humour, which often features jokes that don't conform to convention (such as Monty Python), doesn't travel well to America, where people dislike spending a lot of time trying to figure out why something is funny.

"Even in different areas of Australia, we are subject to different cultural influences and laugh at different jokes," Sharp says. "In fact, even within our major cities, different things amuse us." Since humour can also be a great form of communication, it's important to remember that.

Battle of the sexes

According to psychologist Richard Wiseman's book Quirkology (Pan Macmillan), humour also differs between the sexes. Here's how the different genders shape up.

A year-long study revealed that 71 per cent of women laugh when a man tells a joke, but only 39 per cent of men laugh when a woman tells a joke.

Studies have found that men tell about 60 per cent of all jokes.

Researchers examining the scripts of male and female professional comedians found that 12 per cent of male scripts contained self-disparaging humour compared with 63 per cent of female scripts.

While men like women to laugh at their jokes, they don't like them to tell jokes.

What does your sense of humour say about you?

Humour can provide a window to your personality, says Susan Nicholson.