A link between positive mood and creativity is supported by a study in which 87 students were put into different moods (using music and video clips) and then given a category learning task to do (classifying sets of pictures with visually complex patterns). There were two category tasks: one involved classification on the basis of a rule that could be verbalized; the other was based on a multi-dimensional pattern that could not easily be verbalized.

Happy volunteers were significantly better at learning the rule to classify the patterns than sad or neutral volunteers. There was no difference between those in a neutral mood and those in a negative mood.

It had been theorized that positive mood might only affect processes that require hypothesis testing and rule selection. The mechanism by which this might occur is through increased dopamine levels in the frontal cortex. Interestingly, however, although there was no difference in performance as a function of mood, analysis based on how closely the subjects’ responses matched an optimal strategy for the task found that, again, positive mood was of significant benefit.

The researchers suggest that this effect of positive mood may be the reason behind people liking to watch funny videos at work — they’re trying to enhance their performance by putting themselves in a good mood.

The music and video clips were rated for their mood-inducing effects. Mozart’s “Eine Kleine Nachtmusik—Allegro” was the highest rated music clip (at an average rating of 6.57 on a 7-point scale), Vivaldi’s Spring was next at 6.14. The most positive video was that of a laughing baby (6.57 again), with Whose Line is it Anyway sound effects scoring close behind (6.43).