This is a theory that has been developed by Brian Middleton & Robert Ennis, which stands on the shoulders of the giants that proceed us. The giants who influenced us the most are M. Scott Peck and Abraham Maslow. We highly recommend you look into their works.
This tool is simply offering another perspective on how people develop. It is a working theory. If you have insights or ideas as to how this theory could improve, please feel free to contact Brian via his site ExtremeMultitasker.com, or Robert at OrderOfTheTiger.com.