If this topic intrigues you, this guide is for you: have established the enneagram as the gold standard for defining personality type. In particular, Donald's research on this ancient subject and his success in detecting personality types with increasing accuracy are well known, taught, and documented. a scientific psychological framework applied to many aspects of daily life. This revised and updated edition introduces the brand new, scientifically validated Type Indexer. It has also been refined and simplified to appeal primarily to beginners and anyone interested in discovering the secrets of personality. The most reliable, most accurate, and most accessible way to self-identify type, the enhanced enneagram questionnaire helps identify key character traits, revealing an invaluable guide for change and growth.