New research published by the University of Waterloo found that being grumpy can help improve your attention to detail, time management and ability to prioritise. The same study found that those skills were negatively impacted for people in positive moods.
"Our results show that there are some people for whom a bad mood may actually hone the kind of thinking skills that are important for everyday life," said one of the researchers.
The participants of the study were asked to complete a range of tasks of a number of days, they also had to keep track of their moods when doing the tasks.
"People shouldn’t interpret the results as saying it’s fine to fly off the handle or overreact, or to be grouchy," said McAuley.
"We know that emotional reactivity differs from person to person starting at a very early age and that these individual differences have implications for mental health later in development."
They didn't have any conclusive reasoning for why this may be, but maybe grumpy people tend to shut off from others more meaning they can focus more on other things.