Check out this Chicago Tribune story: Happy is helpful, but fear fosters focus.
A bubbly mood may enhance creativity, but feeling happy can actually hinder the ability to focus on a task, according to a new study.Obviously, this rings true to me. Maybe it also explains why so many creative people are procrastinators who can't focus until they're on deadline.
Researchers found that happy subjects did well when asked to be innovative but that they struggled when they had to concentrate on a simple activity and ignore distractions.
Bring on the heavy metal, I've got to darken my mood.