Is This Why Katy Perry Is "Creative"?

According to a new study by Lorenzo Stafford, a psychologist at the University of Portsmouth, outgoing people in a good mood are more creative than introverts are. In fact, extroverts did twice as well on a word association test when they were in a positive mood than when they were in a negative mood, while introverts' performance barely changed at all.

The reason? Higher levels of the "feel-good" hormone dopamine, Stafford believes:

The more outgoing a person is the more active their dopamine system is and a positive mood increases dopamine activity even further in many parts of the brain. It’s effectively a combination of these two things I would suggest leads to greater activity in certain areas of the brain controlling mental ability.
This is interesting in itself because it demonstrates that it is the combination of the extravert personality-type in a positive mood which encourages more creative performance, and not simply positive mood alone.