Models of self-organization have gained a central importance in psychology and medicine. They explain the spontaneous emergence and change of orderly states in complex systems. This primarily concerns forms of dynamic order, such as chaotic processes. The principles of self-organization underlie a wide range of biological, psychological, and social phenomena, including (gestalt) perception, the construction of meaning and significance, the emergence of affective-cognitive structures (among others in mental disorders like schizophrenia), the functioning of the brain, the effects of psychotherapy, and the development of structure in interpersonal communication. This book provides an overview of the latest research findings in these areas and informs about the current state of methodology in synergetics and chaos research.