Final answer:
The underlying principles of the International Classification of Functioning, Disability and Health (ICF) are based on the biopsychosocial model, which integrates biological, psychological, and social factors to understand health and disability.
Step-by-step explanation:
Underlying Principles of the ICF
The underlying principles of the International Classification of Functioning, Disability and Health (ICF) follow the biopsychosocial model. This model suggests that health and illness are determined by the interplay of biological, psychological, and social factors. Rather than solely focusing on the medical or biological aspects of health and illness (a biological model) or the mind's influence over the body (psychoanalytic model), the biopsychosocial approach integrates these with the impacts of societal contexts, attitudes, and institutions (unlike the purely social model). Understanding the biopsychosocial model, and by extension the ICF, requires a recognition of how these three factors — biological, psychological, and social — dynamically interact to influence human function and disability.
According to the biopsychosocial model, not only does physical health (e.g., the presence of a disorder like bipolar disorder) play a role in a person's functionality and disability, but psychological components (like emotions and behaviors) and social components (such as social support and cultural norms) also have significant influences. This multifactorial view aligns with the multifaceted approach needed to understand the complexity of human health, such as seen in Graph 6 from the provided materials which illustrates the impact of various factors on human immune competence before, during, and after plague outbreaks.