This book is an attempt to add to the theoretical discussion regarding the nature of the intrapsychic and interpersonal transformational changes associated with the transition from adolescence to young adulthood. The author introduces the concept of the 'Transformational Self', a phase-specific dimension of the neural self, and demonstrates the enhanced explanatory power that it offers in attempting to examine the sometimes dramatic shifting self-states accompanying the metamorphosis from adolescence into young adulthood. A necessary precondition for the emergence of the Transformational Self is the maturation of the pre-frontal cortex and its enhanced neural connectivity. With this biological achievement, executive functioning, a strengthened ego/self capacity, can arrive at a mature level of external stabilization and internal, intrapsychic structuralization. Conceptualized in self-referencing metaphor and expressed and reinforced through long term potentiation (repeated firing patterns of synchronous neural assemblies), the late adolescent reconfigured self-state becomes a true developmental potentiality evidenced by the use of different self (and other) representations.