Below are the best videos we could find featuring ken wilber about shadow.
CLEAR ALL
Useful practices for transitioning from the 1st to the 2nd tier of human development.
In my opinion Ken Wilber gets really straight to the point here and is very clear - you'll have to be familiar with stages (Spiral Dynamics) and States however if you want to follow his talk. "Shadow" is a Jungian term for a part of the unconscious mind.
Photo Credit: Flickr user Kanzeon Zen Center / Distributed under the CC BY 2.0 Generic license