The key to happiness is to keep yourself busy in various activities, say experts.

Even doing meaningless or unnecessary tasks makes you feel better than just sitting round getting bored, reports express.co.uk.

Being forced to wait for a quarter of an hour in the airport luggage lounge, for instance, leaves many of us feeling miserable. But if it was placed further away and we had to spend the same time walking there we would be much happier about it.

Unfortunately, our instinct is to be lazy because unless we have a reason for being active we choose to stare blankly into space - an evolutionary development that ensures we conserve energy.

Behavioural scientist professor Christopher Hsee, of the University of Chicago, asked students to complete a questionnaire and then wait 15 minutes.

They could drop off the completed survey nearby and wait out the remaining time or leave it at a place further away, where walking back and forth would keep them busy.

Afterwards the students who decided to walk reported feeling significantly happier than the idle ones. Professor Hsee believes it may be possible to use this principle to benefit society.

'If we can devise a mechanism for idle people to engage in activity that is at least not harmful, I think it is better than destructive idleness,' said Hsee.

'Governments may increase the happiness of idle citizens by having them build bridges that are actually useless,' he added.