MEDICAL MATTERS: SOME OF you may be familiar with TED.com. TED is a non-profit organisation devoted to "ideas worth spreading". It started as a conference bringing together people from the worlds of technology, entertainment and design. As well as running conferences, it makes short talks available on its site - which is well worth dipping into for inspiration and thought-provoking perspectives.
On my most recent visit, I was fascinated by a talk given by Ron Gutman, founder and chief executive of HealthTap, a personalised health information site. The talk was about smiling your way to health and his starting point was a University of California Berkeley 30-year study that examined the photos of students in an old yearbook and tried to measure their success and wellbeing throughout their life.
By measuring smiles, researchers were able to predict how fulfilling and long-lasting a subject's marriage will be, how well she would score on tests of well-being and how inspiring she would be to others.
Apparently, children smile as many as 400 times a day; being around kids makes adults smile. Smiling is contagious and it suppresses the control we usually have over our facial muscles.
According to Gutman mimicking a smile can help us understand whether a smile is fake or real. "In a recent mimicking study at the University of Clermont-Ferrand in France, subjects were asked to determine whether a smile was real or fake while holding a pencil in their mouth to repress smiling muscles. Without the pencil, subjects were excellent judges, but with the pencil in their mouth, when they could not mimic the smile they saw, their judgment was impaired," he says.
German researchers have used fMRI imaging techniques to measure brain activity before and after injecting Botox to suppress smiling muscles. They showed that facial feedback modifies the neural processing of emotional content in the brain in a way that helps us feel better when we smile.
It ties in with a theory put forward by Charles Darwin: that the act of smiling itself makes us feel better rather than smiling just being the result of feeling good.
And British researchers have discovered that one smile can generate the same level of brain stimulation as up to 2,000 bars of chocolate. Of course, that amount of chocolate could cause its own set of health problems, whereas smiling has been shown to reduce the level of hormones such as cortisol and adrenaline, which we pump out when feeling stressed.
Smiling also increases the amount of mood-enhancing hormones such as endorphins in the body. Smiling even reduces blood pressure.
Because humour is found in every culture and ethnic group, it suggests a sense of humour must have appeared fairly early in our evolutionary cycle. The mind-reading hypothesis suggests that what we find funny is observing the wheels turning inside another persons head as they react to changing circumstances.
And research suggests people who initiate humour are seen as more sociable. This may confer a social advantage within groups; being the first to spot a leader's idiosyncrasies may boost your standing.
Smiling can actually make you look good in the eyes of others. Researchers at Penn State University found that when you smile, not only do you appear more likeable and courteous but you also appear more competent.
Separate research that looked at pictures of major league baseball players from before the 1950s found the breadth of a player's smile could predict their lifespan. Non-smilers lived on average until they were 73; those with beaming smiles had an average life span of 80 years.
It's hard to beat Gutman's summary: "So whenever you want to look great and competent, reduce your stress or improve your marriage, or feel as if you just had a whole stack of high-quality chocolate - without incurring the caloric cost - or whenever you want to tap into a superpower that will help you and everyone around you live a longer, healthier, happier life, smile."