The goal of this two-part paper is to familiarize readers with a conceptual contrast, or inconsistency, inherent in the process of adaptation to adversity, trauma, and disability onset. The contrasting viewpoints include, first, the belief that the adaptation process is best understood through adherence to homeostatic principles that underlie human behavior. The opposing view promotes the belief that this process typically follows a trajectory of either disintegration or, more likely, growth, transformation and transcendence into higher functioning levels. In this first paper, the authors attempt to elucidate and reconcile, when possible, this conceptual lacuna. In part I of the first paper, the following steps were applied. First, the concept of homeostasis is reviewed as it is traditionally conceived in both the context of physics and biology, as well as in psychology and human behavior. The review includes historical and modern perspectives on the nature and dynamics of homeostasis. Second, an overview of growth and transcendence models, in the fields of psychology and human behavior, is provided. Discussed are both early and modern contributions to these fields. In the second, separate, paper, applications of growth and transcendence models to coping with adversity, trauma and onset of disabling conditions are discussed. Next, a preliminary conceptual model of adaptation, and its underlying postulates, seeking to integrate the homeostatic and growth models into a dynamically unified concentric model, while preserving each of the models' main structural components, is offered. The second paper concludes with relevant research directions necessary to validate the model's preliminary structure.
Clinical Impact StatementThe concepts discussed, and the model proposed, in this two-part manuscript suggest two primary clinical impact venues, namely, conceptual-clinical, and goal setting-clinical:• The proposed (see Part II), although admittingly in need of further theoretical elaboration and empirical support, nevertheless, provides clinicians with a broad conceptual framework on how to address issues pertaining to psychosocial adaptation to traumatic experiences and onset of life-threatening medical conditions, using the concepts of homeostasis (regaining previously experienced functional levels) and personal growth (transitioning to higher levels of psychological, interpersonal, and spiritual experiences following trauma onset). • The proposed model, and associated discussion, could prepare clinicians to better conceive and plan therapeutic strategies, being cognizant of the model's preliminary developmental stages, that examine whether resumption of previously experienced homeostatic life functioning is more plausible, or under which conditions transition, or transformation, to higher level growth-producing functioning may be more appropriate, recognizing such factors as threat to one's stress level boundaries, limits of regulatory/normative homeostatic functioning, and anticipation of psychological break threshol...