Biological Function and Dysfunction

This chapter examines recent developments in the philosophical analysis of the concept of biological function. It focuses on etiological or historical accounts that interpret functions primarily as naturally selected effects. This approach to function is most relevant to evolutionary psychology and the most philosophically adequate approach. The chapter illustrates how the etiological analysis of function yields a notion of dysfunction that illuminatingly addresses conceptual questions at the foundation of evolutionary psychopathology. It focuses on a more fundamental issue for clinical psychology, namely, clarifying the concept of mental disorder itself. The chapter presents some practical implications for psychiatric diagnosis of taking an evolutionary perspective. The harmful dysfunction (HD) analysis holds that the intuitive concept of disorder requires dysfunction, and dysfunction in the relevant sense refers to processes of failure of natural design. The evolutionary theoretical argument applied in the case of function applies to dysfunction as well.