By Jackie Storer
Is the fridge half empty or half full?
Why do some people look you straight in the eye when they are talking to you, while others let their gaze fall to the floor? A psychologist in America says its all down to whether you are an optimist or a pessimist.
Apparently, happy, cheerful souls are more likely to look upwards when they are thinking, while those who favour a more depressed disposition will look down.
The research by psychologist Brian Meier at the North Dakota State University suggests that changing postures could actually change a
"It suggests it may be possible to relieve depression simply by persuading them to break their habits and move their gaze upwards," he says.
So should we all bear in mind the words of that great playwright and poet Oscar Wilde when he observed: "We are all in the gutter, but some of us are looking at the stars"?
What are the other benefits of looking upwards, apart from giving an insight to our personality traits? Do toddlers always seem to look skywards, because to them, the only way is up?
Wander round Westminster during a busy lunch-hour and it is easy to see why people might feel happier if they averted their gaze from the ground.
You can miss the full beauty of Big Ben if you don't look upwards
By looking upwards, you can take in the full glory of some of Britain's finest architecture. Parts of buildings you may never have noticed become apparent.
Without looking skywards, you would certainly miss the gold Roman numerals on the clock at Westminster Abbey.
You wouldn't appreciate the gradual motion of the London Eye, or the soaring tower of Big Ben. You might never notice the dome at the top of the Methodist Central Hall or the prettiness of the odd hanging basket.
But there again, looking upwards means you might also notice the sky is grey, despite it being mid-summer. You may also be surprised at how really ugly the Queen Elizabeth II Conference Centre is.
Keep your eyes on the ground and cracks in the pavement become apparent. You can see fag butts, discarded drinks cartons, puddles, drains, dead leaves, chewing gum and newspaper billboards crying out with depressing headlines like: "3,000 armed police hunt bombers".
Richard Brindley, director of practice at the Royal Institute of British Architects, said: "Architects are very conscious of skylines - all buildings need good tops.
"They say you can always tell the architect because he tends to be looking up - we are very concerned about the over all form of the building."
According to Cary Cooper, a professor of organisational psychology and health at Lancaster University, where a person looks is usually a good indicator of their underlying personality.
"If when you are just walking around you tend to look at the pavement and you don't look at what's happening around you, I can see that being symptomatic of someone who is pessimistic, less self confident," he says.
But look down and - oh dear
"People who avoid eye contact are less self confident, less optimistic," he says. "Looking down may be an indication of avoiding eye contact so you can see that being a characteristic of a pessimist."
However, if you look to the sky, you are more likely to be a glass half full person, than a glass half empty, he says.
"In public life, almost by definition, the kind of people who are of celebrity status, i.e. successful, are more likely to be optimistic people. They wouldn't get where they are if they were negative," he says. "That's a characteristic. They see obstacles as opportunities. They are not pessimistic."
So apply the theory to those walking round Westminster at lunchtime and what do you see? Most people seemed to be looking straight ahead... talking on their mobile phones.