An attack of the grumps can make you communicate better, it is suggested
In a bad mood? Don't worry - according to research, it's good for you.
An Australian psychology expert who has been studying emotions has found being grumpy makes us think more clearly.
In contrast to those annoying happy types, miserable people are better at decision-making and less gullible, his experiments showed.
While cheerfulness fosters creativity, gloominess breeds attentiveness and careful thinking, Professor Joe Forgas told Australian Science Magazine.
The University of New South Wales researcher says a grumpy person can cope with more demanding situations than a happy one because of the way the brain "promotes information processing strategies".
He asked volunteers to watch different films and dwell on positive or negative events in their life, designed to put them in either a good or bad mood.
Next he asked them to take part in a series of tasks, including judging the truth of urban myths and providing eyewitness accounts of events.
Those in a bad mood outperformed those who were jolly - they made fewer mistakes and were better communicators.
Professor Forgas said: "Whereas positive mood seems to promote creativity, flexibility, co-operation and reliance on mental shortcuts, negative moods trigger more attentive, careful thinking, paying greater attention to the external world."
The study also found that sad people were better at stating their case through written arguments, which Forgas said showed that a "mildly negative mood may actually promote a more concrete, accommodative and ultimately more successful communication style".
His earlier work shows the weather has a similar impact on us - wet, dreary days sharpened memory, while bright sunny spells make people forgetful.
We asked you for your views on this story. Please find a selection of your comments below.
Halleluiah! I intend to show this to everyone who's ever branded me with various epithets for being "negative".
Marcy Sheiner, USA
Being grumpy raises my blood pressure and I usually make wrong decisions when I am grumpy. I usually sleep on it, relax and then make a decision which is usually the correct decision. I don't like grumpy people and I usually avoid them.
Iftikharuddin Faruqui, Pakistan
Absolutely right. There is certainly no point that I can see in viewing the world through rose-coloured spectacles. Anybody who wanders through life in a continuous state of bonhomie either has no idea what's going on around them or simply doesn't care! All my close friends are similar in temperament. We would inevitably consider those who do not fit the criteria to be shallow and lacking in perception. And yes, I am still at peace within myself for all the reasons stated in the article.
Dave Gordon, Exeter, UK
I am generally a very grumpy person, but I have definitely noticed my decision making and general awareness is far higher than that of my friends who are normally much happier, jollier and generally carefree. I love being grumpy, it's clearly an advantage!
David James Keeves, Loughborough, UK
Ah! This study provides a plausible explanation of Schopenhauer's philosophical clarity and superb prose. And yet, paradoxically, the Great Grump has had a more profound influence beyond philosophy, in the realm of all those cheerful, creative artists.
Cheryl F, South Kingstown, Rhode Island, USA
I find I am happier when I am just a little grumpy. The grumpy feeling seems to aid me in concentrating on menial tasks. Maybe in this stressful modern era a touch of grumpy is all that's needed rather than anti-depressants and other drugs.
Derek Penn, Falmouth, Cornwall, UK
As a self-confessed misery, I work on the premise that "misery is the thinking man's happiness". With misery comes a distinctive humour and a more realistic outlook on life, that actually makes me a more rounded and "real" person than those around me with a painted smile on their faces. I enjoy being grumpy and wouldn't have it any other way.
Dave Woods, Coventry, UK
Could it not also be argued or proven, possibly, that making decisions while grumpy can lead one to make rash decisions? Or is that only when you're angry - since angry and grumpy are not the same thing?
Parker, Louisiana, USA
I'm often identified by friends as someone who can be pessimistic, sometimes without any real reason. I also tick the box of sceptic - which I guess goes under the category of being less gullible. I won't say any more about my intelligence for fear of immodesty!
Chris Baker, Southampton, UK
I work with the grumpiest man in the world and he doesn't seem to be any more clever than me!
Gary, Watford, UK
Being grumpy or depressed goes hand in hand with thinking. When you're continually happy you can just skim along on the surface of life and not examine anything too deeply. Which is cause and which is effect, I don't know.
Amanda, Ely, UK