The book states that procrastination is caused by anxiety, and I agree. Perfectionism is just one way to create anxiety. Frustration, boredom, frustration are others.

We put off the task to avoid these negative emotions IN THE FUTURE. The definition of anxiety is anticipating something bad in the future, so we can avoid it.

Techniques like the Unschedule work extremely well for me and other people. Other things that work well is splitting the task into sub-task, writing everything down, recording the intensity of what you do.