When you're feeling cranky or upset, it might feel like the worst time to tackle a problem or do something creative. A study by the British Psychological Society implies that may in fact not be the case.
The researchers found, while examining 100 creative professionals, that those who were in bad moods at the start of the day were more persistent in trying to find a solution to problems. Being cranky at the start might suck, but that energy and momentum can keep you going once you get started, even when your mood has long-since simmered. Or, to put it scientifically:
The narrow, alert focus on issues can be useful by focusing on things that are in need of a solution and spurring motivation to act on these; previous research does suggest that negative emotion can lead to more persistence in problem solving. Once this focus has been set, allowing the negative emotions to slide away and positive emotions to explore the possibility space is a good recipe for getting to innovative solutions.
Of course, doing things to upset yourself for no other reason than to be in a bad mood won't help. However, the next time you find yourself frustrated or angry find a way to funnel that energy into something productive or creative.