As researchers estimate that chirpy folks are more likely to be alive ten years more than the least happy participants, it may not be all bad for the grumpy types.

In fact, a host of research shows that it is life's "Victor Meldrews" who often fare better in the long term.

Plus, forcing yourself to cheer up can cause debilitating stress, the Daily Mail.

For a start, optimism is not always as healthy as it might sound.

Rather, being a Pollyanna can have a dark side, as shown by a long-term study.

Psychologists followed the lives of 1,216 children who were first assessed in 1922.

They found that those who were rated as more happily optimistic died earlier in adult life than those who were more doleful.

The researchers, from the University of California, warned that the cheery youths grew up more likely to drink, smoke and take more risks.

This was most likely because their jolly optimism clouded their judgement and made the dangers appear insignificant.

"Although optimism has been shown to have positive effects when people are faced with a short-term crisis, the long-term effects of cheerfulness are more complex," the report said.

Being glum also seems to be a far more natural response to difficult times, as it can enable us to cope better during tough situations.

This is according to a 2007 Australian study. Through a series of tough intelligence tests, it was found that people who were in a bad mood outperformed the cheerful participants.

"They made fewer mistakes and were better communicators. In contrast to happy types, miserable people are better at decision-making and less gullible," researchers said.

John Maule, a professor of decision-making at Leeds University, explains that a broad body of research supports this idea.

"People in negative moods tend to think more deeply and in a more analytical style, and rely less on intuition," he said, adding that being a grump can enable us to think more clearly in hard times.

"Negative emotions flag up the fact there is a problem that the person needs to focus on. Positive moods signal the opposite — that you are in a position to freewheel."

"Both emotions, in their appropriate place, help us to live in a healthy manner," he said.

Furthermore, feeling obliged to keep smiling does not make us any happier — in fact, there are deadly dangers of feeling forced to cheer up, psychologist Professor Dieter Zapf said.

His studies of more than 4,000 workers have found that public-facing workers, such as shop assistants, suffer increased risks of depression, high blood pressure and cardiovascular problems, through the stress of having to constantly grin while on duty.

The study is published in the journal Personality and Social Psychology Bulletin.